fix(maestro): match the web form's distinct branch-field labels in the TUI (#94)

The draft pane's new-branch gutter was labelled "br:" in both branch
modes — since #94's web fix now says "New branch name" / "Pick a
branch", mirror the same distinction here: "new:" for the branch-name
input, "pick:" for the existing-branch list (which previously had no
label at all).

.gitea/workflows/ci.yml

@@ -97,3 +97,24 @@ jobs:
 
       - name: build
         run: pnpm -C web build
+
+  # The flake pins pnpmDeps.hash against web/pnpm-lock.yaml (#98). A lockfile
+  # change invalidates the pin silently elsewhere, so the packaged build has to
+  # fail here too.
+  flake:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install nix
+        run: |
+          curl -fsSL https://nixos.org/nix/install | sh -s -- --daemon --yes
+          echo "/nix/var/nix/profiles/default/bin" >> "$GITHUB_PATH"
+
+      - name: build flake packages
+        run: |
+          nix build \
+            .#webFrontend \
+            .#maestro \
+            .#maestro-web \
+            --no-link

CLAUDE.md

@@ -62,6 +62,10 @@ nix/                     # Home Manager module (`services.maestro`)
 
 See `docs/INSTALL.md` for end-user install instructions.
 
+`docs/WORKTREES.md` is the contract for session worktrees — placement,
+collisions, what blocks a kill, what `--force` retains, and what reclaim
+touches. Read it before changing anything that creates or removes one.
+
 `nix run .#dev` (or `just dev`) brings up the whole local stack under
 process-compose: a debug daemon on 127.0.0.1:7071, then Vite on :5173 once the
 daemon answers `/api/info`. The SPA proxies `/api/*` back to the daemon, so only

crates/maestro-cli/src/cli.rs

@@ -41,6 +41,36 @@ pub enum Command {
     Attach(AttachArgs),
     /// Kill a session by ID.
     Kill(KillArgs),
+    /// List retained worktrees, or reclaim one by ID (#86).
+    Worktrees(WorktreesArgs),
+}
+
+/// `maestro worktrees <list|reclaim>`
+#[derive(Debug, clap::Args)]
+pub struct WorktreesArgs {
+    #[command(subcommand)]
+    pub command: WorktreesCommand,
+}
+
+#[derive(Debug, Subcommand)]
+pub enum WorktreesCommand {
+    /// List retained worktrees and what is in the way of reclaiming each.
+    List(ListWorktreesArgs),
+    /// Reclaim one retained worktree: removes the directory, never the branch.
+    Reclaim(ReclaimArgs),
+}
+
+#[derive(Debug, clap::Args)]
+pub struct ListWorktreesArgs {
+    /// Output as JSON instead of a table.
+    #[arg(long)]
+    pub json: bool,
+}
+
+#[derive(Debug, clap::Args)]
+pub struct ReclaimArgs {
+    /// Retained worktree ID to reclaim. Required — there is no reclaim-all.
+    pub id: Uuid,
 }
 
 #[derive(Debug, clap::Args)]
@@ -72,11 +102,6 @@ pub struct SpawnArgs {
     /// there.
     #[arg(long)]
     pub existing_branch: bool,
-    /// Remove the worktree when the session is killed. Kept for wire
-    /// compatibility (#56): the daemon now always cleans up on kill, guarded
-    /// against unsaved work.
-    #[arg(long, default_value_t = true)]
-    pub cleanup_on_kill: bool,
     /// After spawning, attach immediately.
     #[arg(long, short = 'a')]
     pub attach: bool,
@@ -95,6 +120,11 @@ pub struct AttachArgs {
 pub struct KillArgs {
     /// Session ID to kill.
     pub session_id: Uuid,
+    /// End the session even when its worktree holds unsaved work (#81). The
+    /// worktree is retained — never removed — and enters the retained store;
+    /// the output says where the work went.
+    #[arg(long)]
+    pub force: bool,
 }
 
 fn parse_kv(s: &str) -> Result<(String, String), String> {
@@ -133,7 +163,6 @@ mod tests {
             "/repos/foo",
             "--branch",
             "feat/x",
-            "--cleanup-on-kill",
             "-e",
             "FOO=bar",
             "-e",
@@ -144,7 +173,6 @@ mod tests {
             Command::Spawn(a) => {
                 assert_eq!(a.command, "bash");
                 assert_eq!(a.branch.as_deref(), Some("feat/x"));
-                assert!(a.cleanup_on_kill);
                 assert_eq!(
                     a.env,
                     vec![("FOO".into(), "bar".into()), ("BAZ".into(), "qux".into()),]
@@ -154,27 +182,6 @@ mod tests {
         }
     }
 
-    #[test]
-    fn cleanup_on_kill_defaults_true_for_the_wire() {
-        let cli = Cli::try_parse_from([
-            "maestro",
-            "spawn",
-            "--cwd",
-            "/tmp",
-            "--command",
-            "bash",
-            "--worktree-from",
-            "/repos/foo",
-            "--branch",
-            "feat/x",
-        ])
-        .unwrap();
-        match cli.command {
-            Command::Spawn(a) => assert!(a.cleanup_on_kill),
-            _ => panic!("wrong subcommand"),
-        }
-    }
-
     /// Review fix: without a flag the CLI always sent `create_branch: true`,
     /// so the daemon's existing-branch path was unreachable and spawning onto
     /// a branch that already existed just failed.
@@ -226,6 +233,32 @@ mod tests {
         }
     }
 
+    #[test]
+    fn parses_kill_with_force() {
+        let id = "01234567-89ab-cdef-0123-456789abcdef";
+        let cli = Cli::try_parse_from(["maestro", "kill", "--force", id]).unwrap();
+        match cli.command {
+            Command::Kill(a) => {
+                assert!(a.force);
+                assert_eq!(a.session_id.to_string(), id);
+            }
+            _ => panic!("wrong subcommand"),
+        }
+    }
+
+    #[test]
+    fn kill_force_defaults_false() {
+        let id = "01234567-89ab-cdef-0123-456789abcdef";
+        let cli = Cli::try_parse_from(["maestro", "kill", id]).unwrap();
+        match cli.command {
+            Command::Kill(a) => {
+                assert!(!a.force);
+                assert_eq!(a.session_id.to_string(), id);
+            }
+            _ => panic!("wrong subcommand"),
+        }
+    }
+
     #[test]
     fn rejects_env_without_equals() {
         let err = Cli::try_parse_from([
@@ -241,4 +274,56 @@ mod tests {
         .unwrap_err();
         assert!(err.to_string().contains("KEY=VALUE"));
     }
+
+    #[test]
+    fn parses_worktrees_list() {
+        let cli = Cli::try_parse_from(["maestro", "worktrees", "list", "--json"]).unwrap();
+        match cli.command {
+            Command::Worktrees(w) => match w.command {
+                WorktreesCommand::List(a) => assert!(a.json),
+                _ => panic!("wrong worktrees subcommand"),
+            },
+            _ => panic!("wrong subcommand"),
+        }
+    }
+
+    #[test]
+    fn parses_worktrees_reclaim() {
+        let id = "01234567-89ab-cdef-0123-456789abcdef";
+        let cli = Cli::try_parse_from(["maestro", "worktrees", "reclaim", id]).unwrap();
+        match cli.command {
+            Command::Worktrees(w) => match w.command {
+                WorktreesCommand::Reclaim(a) => assert_eq!(a.id.to_string(), id),
+                _ => panic!("wrong worktrees subcommand"),
+            },
+            _ => panic!("wrong subcommand"),
+        }
+    }
+
+    /// Contract rule: reclaim refuses to run without an explicit target.
+    /// There is no reclaim-everything convenience.
+    #[test]
+    fn reclaim_requires_an_explicit_target() {
+        let err = Cli::try_parse_from(["maestro", "worktrees", "reclaim"]).unwrap_err();
+        assert!(
+            matches!(
+                err.kind(),
+                clap::error::ErrorKind::InvalidSubcommand
+                    | clap::error::ErrorKind::MissingRequiredArgument
+            ),
+            "{err}"
+        );
+    }
+
+    #[test]
+    fn worktrees_without_subcommand_shows_help() {
+        let err = Cli::try_parse_from(["maestro", "worktrees"]).unwrap_err();
+        assert!(
+            matches!(
+                err.kind(),
+                clap::error::ErrorKind::DisplayHelpOnMissingArgumentOrSubcommand
+            ),
+            "{err}"
+        );
+    }
 }

crates/maestro-cli/src/dispatch.rs

@@ -9,8 +9,9 @@ use std::path::{Path, PathBuf};
 use maestro_protocol::DaemonClient;
 
 use crate::attach::{parse_detach_key, run_attach_url};
-use crate::cli::Command;
+use crate::cli::{Command, WorktreesCommand};
 use crate::sessions::{run_kill, run_list, run_spawn};
+use crate::worktrees::{run_list as run_worktree_list, run_reclaim as run_worktree_reclaim};
 use maestro_config::{default_config_path, MaestroConfigFile};
 
 #[derive(Debug, thiserror::Error)]
@@ -61,9 +62,41 @@ pub async fn dispatch(
             run_attach_url(&daemon.attach_url(args.session_id)?, detach).await?;
         }
         Command::Kill(args) => {
-            run_kill(&daemon, &args).await?;
+            // #83: warn BEFORE the attempt, so the refusal is not a surprise.
+            // Best-effort: an unreachable list must not block the kill.
+            if !args.force {
+                warn_if_blocked(&daemon, args.session_id).await;
+            }
+            let outcome = run_kill(&daemon, &args).await?;
             println!("killed {}", args.session_id);
+            if let Some(w) = outcome.retained {
+                println!(
+                    "worktree retained at {} (branch {}, force-killed)",
+                    w.path.display(),
+                    w.branch
+                );
+            }
         }
+        Command::Worktrees(args) => match args.command {
+            WorktreesCommand::List(list_args) => {
+                let mut stdout = std::io::stdout().lock();
+                run_worktree_list(&daemon, &list_args, &mut stdout).await?;
+            }
+            WorktreesCommand::Reclaim(reclaim_args) => {
+                // The daemon removes the directory and the store entry; the
+                // branch is never deleted — worth saying out loud (#86).
+                let entry = run_worktree_reclaim(&daemon, &reclaim_args).await?;
+                match entry {
+                    Some(wt) => println!(
+                        "reclaimed {} ({})\nbranch '{}' kept",
+                        wt.id,
+                        wt.path.display(),
+                        wt.branch
+                    ),
+                    None => println!("reclaimed {}\nbranch kept", reclaim_args.id),
+                }
+            }
+        },
     }
     Ok(())
 }
@@ -71,6 +104,25 @@ pub async fn dispatch(
 /// Default detach byte, matching `maestro attach --detach-key`'s `^q`.
 const CTRL_Q: u8 = 0x11;
 
+/// #83: say "this will be refused" before the operator commits to it, in the
+/// same words [`maestro_protocol::InTheWay`] uses everywhere else.
+async fn warn_if_blocked(daemon: &DaemonClient, id: uuid::Uuid) {
+    let Ok(sessions) = daemon.list_sessions().await else {
+        return;
+    };
+    if let Some(b) = sessions
+        .iter()
+        .find(|s| s.id == id)
+        .and_then(|s| s.blocked_work)
+    {
+        if !b.is_clear() {
+            eprintln!(
+                "warning: this kill will be refused — the session's worktree holds unsaved work ({b}); use --force to retain it"
+            );
+        }
+    }
+}
+
 /// HTTP client pointed at the daemon's API. That surface needs no auth —
 /// reaching `bind_addr` is the authorization.
 #[allow(clippy::result_large_err)]

crates/maestro-cli/src/lib.rs

@@ -6,5 +6,6 @@ pub mod attach;
 pub mod cli;
 pub mod dispatch;
 pub mod sessions;
+pub mod worktrees;
 
 pub use dispatch::{dispatch, CliError};

crates/maestro-cli/src/sessions.rs

@@ -43,7 +43,6 @@ pub async fn run_spawn(client: &DaemonClient, args: SpawnArgs) -> Result<Session
         (Some(repo), Some(branch)) => Some(WorktreeSpec {
             base_repo: repo.clone(),
             branch: branch.clone(),
-            cleanup_on_kill: args.cleanup_on_kill,
             create_branch: !args.existing_branch,
         }),
         _ => None,
@@ -59,9 +58,14 @@ pub async fn run_spawn(client: &DaemonClient, args: SpawnArgs) -> Result<Session
     client.create_session(&body).await
 }
 
-/// `maestro kill`
-pub async fn run_kill(client: &DaemonClient, args: &KillArgs) -> Result<(), ClientError> {
-    client.kill_session(args.session_id).await
+/// `maestro kill`. A forced kill (#81) retains the guarded worktree instead
+/// of removing it; the outcome names what was kept so dispatch can say where
+/// the work went.
+pub async fn run_kill(
+    client: &DaemonClient,
+    args: &KillArgs,
+) -> Result<maestro_protocol::KillOutcome, ClientError> {
+    client.kill_session(args.session_id, args.force).await
 }
 
 #[allow(clippy::write_literal)]
@@ -89,8 +93,8 @@ fn print_session_table(out: &mut impl Write, sessions: &[Session], info: &Daemon
     }
     writeln!(
         out,
-        "  {:<36}  {:<8}  {:<9}  {:<28}  {}",
-        "ID", "STATUS", "ACTIVITY", "DIR", "COMMAND"
+        "  {:<36}  {:<8}  {:<9}  {:<28}  {:<40}  {}",
+        "ID", "STATUS", "ACTIVITY", "DIR", "COMMAND", "BLOCKED"
     )
     .ok();
     for s in sorted {
@@ -111,18 +115,31 @@ fn print_session_table(out: &mut impl Write, sessions: &[Session], info: &Daemon
             Some(fg) if fg != &s.command => format!("{} [{}]", s.command, fg),
             _ => s.command.clone(),
         };
+        // #83: what an unforced kill would be refused for, in InTheWay's own
+        // words; blank while nothing blocks (or hasn't been probed yet).
+        let blocked = blocked_label(s);
         writeln!(
             out,
-            "  {:<36}  {:<8}  {:<9}  {:<28}  {command}",
-            s.id, status, activity, dir
+            "  {:<36}  {:<8}  {:<9}  {:<28}  {:<40}  {blocked}",
+            s.id, status, activity, dir, command
         )
         .ok();
     }
 }
 
+/// The blocked-work indicator (#83), phrased by [`InTheWay`]'s `Display`.
+/// Empty unless something actually blocks — "no unsaved work" would just be
+/// noise on every row.
+pub(crate) fn blocked_label(s: &Session) -> String {
+    s.blocked_work
+        .filter(|b| !b.is_clear())
+        .map(|b| b.to_string())
+        .unwrap_or_default()
+}
+
 /// Render a path with the daemon's home dir collapsed to `~`. Mirrors the web
 /// UI's abbreviation so CLI and browser show the same directory shorthand.
-fn abbreviate_dir(path: &std::path::Path, home: &str) -> String {
+pub(crate) fn abbreviate_dir(path: &std::path::Path, home: &str) -> String {
     let p = path.to_string_lossy();
     if !home.is_empty() {
         if p == home {
@@ -153,12 +170,14 @@ mod tests {
             command: command.into(),
             env: HashMap::new(),
             metadata: HashMap::new(),
+            worktree: None,
             status: SessionStatus::Running,
             created_at: Utc.with_ymd_and_hms(2026, 5, 25, 12, 0, 0).unwrap(),
             foreground: None,
             activity: Default::default(),
             last_activity_at: chrono::Utc::now(),
             current_cwd: None,
+            blocked_work: None,
         }
     }
 
@@ -219,4 +238,37 @@ mod tests {
         super::print_session_table(&mut buf, &[], &info(""));
         assert_eq!(String::from_utf8(buf).unwrap(), "no sessions\n");
     }
+
+    /// #83: a blocked session shows what an unforced kill would be refused
+    /// for, in `InTheWay`'s own words; a clear or unprobed one shows nothing.
+    #[test]
+    fn shows_the_blocked_work_summary_only_when_something_blocks() {
+        use maestro_protocol::InTheWay;
+
+        let mut blocked = session("/tmp", "claude", 1);
+        blocked.blocked_work = Some(InTheWay {
+            uncommitted_files: 3,
+            unpushed_commits: 2,
+            ..InTheWay::default()
+        });
+        let mut clear = session("/tmp", "bash", 2);
+        clear.blocked_work = Some(InTheWay::default());
+        let unprobed = session("/tmp", "zsh", 3);
+
+        let mut buf = Vec::new();
+        super::print_session_table(&mut buf, &[blocked, clear, unprobed], &info(""));
+        let out = String::from_utf8(buf).unwrap();
+        assert!(
+            out.contains("3 uncommitted files, 2 unpushed commits"),
+            "{out}"
+        );
+        // Clear and unprobed rows stay blank in the BLOCKED column.
+        let lines: Vec<&str> = out.lines().collect();
+        let header = lines.iter().position(|l| l.contains("BLOCKED")).unwrap();
+        for line in &lines[header + 1..] {
+            if !line.contains("uncommitted files") {
+                assert!(!line.contains("unsaved work"), "{line}");
+            }
+        }
+    }
 }

crates/maestro-cli/src/worktrees.rs

@@ -0,0 +1,204 @@
+//! `maestro worktrees list / reclaim` — the retained-store surface (#86).
+//!
+//! `reclaim` removes one directory; it never deletes the branch, which is
+//! said out loud in the output because "reclaim" otherwise sounds like it
+//! takes the commits too.
+
+use std::io::Write;
+
+use maestro_protocol::{ClientError, DaemonClient, DaemonInfo, InTheWay, RetainedWorktree};
+
+use crate::cli::{ListWorktreesArgs, ReclaimArgs};
+use crate::sessions::abbreviate_dir;
+
+/// `maestro worktrees list`
+pub async fn run_list(
+    client: &DaemonClient,
+    args: &ListWorktreesArgs,
+    out: &mut impl Write,
+) -> Result<(), ClientError> {
+    let worktrees = client.list_worktrees().await?;
+    let info = client.daemon_info().await.unwrap_or_default();
+
+    if args.json {
+        let body = serde_json::json!({ "worktrees": worktrees });
+        writeln!(out, "{}", serde_json::to_string_pretty(&body)?).ok();
+        return Ok(());
+    }
+
+    print_worktree_table(out, &worktrees, &info);
+    Ok(())
+}
+
+/// `maestro worktrees reclaim <id>`
+///
+/// Returns the entry as listed just before the reclaim, when it was found in
+/// the listing, so the confirmation can name what was removed.
+pub async fn run_reclaim(
+    client: &DaemonClient,
+    args: &ReclaimArgs,
+) -> Result<Option<RetainedWorktree>, ClientError> {
+    let listed = client
+        .list_worktrees()
+        .await?
+        .into_iter()
+        .find(|w| w.id == args.id);
+    client.reclaim_worktree(args.id).await?;
+    Ok(listed)
+}
+
+fn print_worktree_table(out: &mut impl Write, worktrees: &[RetainedWorktree], info: &DaemonInfo) {
+    if worktrees.is_empty() {
+        writeln!(out, "no retained worktrees").ok();
+        return;
+    }
+
+    let mut sorted: Vec<&RetainedWorktree> = worktrees.iter().collect();
+    sorted.sort_by_key(|w| w.retained_at);
+
+    if !info.hostname.is_empty() {
+        let warn = if maestro_protocol::is_compatible(&info.version) {
+            ""
+        } else {
+            "  (protocol mismatch)"
+        };
+        let version = if info.version.is_empty() {
+            String::new()
+        } else {
+            format!("  maestro {}{warn}", info.version)
+        };
+        writeln!(out, "\n{}{version}", info.hostname).ok();
+    }
+    writeln!(
+        out,
+        "  {:<36}  {:<24}  {:<28}  {:<24}  IN THE WAY",
+        "ID", "BRANCH", "PATH", "REASON"
+    )
+    .ok();
+    for w in sorted {
+        writeln!(
+            out,
+            "  {:<36}  {:<24}  {:<28}  {:<24}  {}",
+            w.id,
+            w.branch,
+            abbreviate_dir(&w.path, &info.home_dir),
+            reason_label(w.reason),
+            blocker_label(&w.in_the_way),
+        )
+        .ok();
+    }
+    // The branch survives every reclaim — see docs/WORKTREES.md.
+    writeln!(
+        out,
+        "\nreclaim removes the directory only; branches are never deleted"
+    )
+    .ok();
+}
+
+fn reason_label(reason: maestro_protocol::RetainedReason) -> &'static str {
+    match reason {
+        maestro_protocol::RetainedReason::ForceKilled => "force-killed",
+        maestro_protocol::RetainedReason::ExitedWithUnsavedWork => "exited-with-unsaved-work",
+    }
+}
+
+/// The same breakdown that blocks an unforced kill, as words: what is still
+/// in the way, or `clear` when the work has since been committed and pushed.
+fn blocker_label(in_the_way: &InTheWay) -> String {
+    if in_the_way.is_clear() {
+        return "clear".into();
+    }
+    let mut parts: Vec<String> = Vec::new();
+    if in_the_way.uncommitted_files > 0 {
+        parts.push(format!("{} uncommitted", in_the_way.uncommitted_files));
+    }
+    if in_the_way.untracked_files > 0 {
+        parts.push(format!("{} untracked", in_the_way.untracked_files));
+    }
+    if in_the_way.unpushed_commits > 0 {
+        parts.push(format!("{} unpushed", in_the_way.unpushed_commits));
+    }
+    parts.join(", ")
+}
+
+#[cfg(test)]
+mod tests {
+    use std::path::PathBuf;
+
+    use chrono::{TimeZone, Utc};
+    use maestro_protocol::{DaemonInfo, InTheWay, RetainedReason, RetainedWorktree};
+    use uuid::Uuid;
+
+    fn worktree(branch: &str, path: &str, id: u128) -> RetainedWorktree {
+        RetainedWorktree {
+            id: Uuid::from_u128(id),
+            path: PathBuf::from(path),
+            base_repo: PathBuf::from("/home/naps/maestro"),
+            branch: branch.into(),
+            reason: RetainedReason::ForceKilled,
+            retained_at: Utc.with_ymd_and_hms(2026, 8, 24, 10, 0, 0).unwrap(),
+            in_the_way: InTheWay::default(),
+        }
+    }
+
+    fn info(home: &str) -> DaemonInfo {
+        DaemonInfo {
+            hostname: "naps-laptop".into(),
+            home_dir: home.into(),
+            ..Default::default()
+        }
+    }
+
+    #[test]
+    fn formats_table() {
+        let mut w = worktree("feat/login", "/home/naps/maestro/worktrees/feat/login", 1);
+        w.in_the_way = InTheWay {
+            uncommitted_files: 2,
+            untracked_files: 1,
+            unpushed_commits: 3,
+        };
+        let mut buf = Vec::new();
+        super::print_worktree_table(&mut buf, &[w], &info("/home/naps"));
+        let s = String::from_utf8(buf).unwrap();
+        assert!(s.contains("naps-laptop"), "{s}");
+        assert!(s.contains("feat/login"), "{s}");
+        // Home dir collapses to ~ in the PATH column, like sessions' DIR.
+        assert!(s.contains("~/maestro/worktrees/feat/login"), "{s}");
+        assert!(s.contains("force-killed"), "{s}");
+        assert!(s.contains("2 uncommitted, 1 untracked, 3 unpushed"), "{s}");
+        assert!(s.contains("IN THE WAY"), "{s}");
+    }
+
+    /// Contract rule, visible to the operator: reclaiming a tree must not
+    /// throw away commits on its branch.
+    #[test]
+    fn says_the_branch_survives() {
+        let mut buf = Vec::new();
+        super::print_worktree_table(
+            &mut buf,
+            &[worktree("feat/x", "/repo/worktrees/feat/x", 1)],
+            &info(""),
+        );
+        let s = String::from_utf8(buf).unwrap();
+        assert!(s.contains("never deleted"), "{s}");
+    }
+
+    #[test]
+    fn clear_tree_says_clear() {
+        let mut buf = Vec::new();
+        super::print_worktree_table(
+            &mut buf,
+            &[worktree("main-ish", "/repo/worktrees/main-ish", 1)],
+            &info(""),
+        );
+        let s = String::from_utf8(buf).unwrap();
+        assert!(s.contains("clear"), "{s}");
+    }
+
+    #[test]
+    fn empty_store() {
+        let mut buf = Vec::new();
+        super::print_worktree_table(&mut buf, &[], &info(""));
+        assert_eq!(String::from_utf8(buf).unwrap(), "no retained worktrees\n");
+    }
+}

crates/maestro-cli/tests/against_mock_daemon.rs

@@ -76,7 +76,7 @@ async fn killing_an_unknown_session_reports_the_daemon_reason() {
 
     let err = mock
         .client()
-        .kill_session(Uuid::new_v4())
+        .kill_session(Uuid::new_v4(), false)
         .await
         .expect_err("should fail");
 
@@ -102,6 +102,9 @@ async fn spawn_round_trips_through_the_daemon() {
     assert_eq!(created.command, "bash");
     assert_eq!(mock.session_count(), 1);
 
-    mock.client().kill_session(created.id).await.expect("kill");
+    mock.client()
+        .kill_session(created.id, false)
+        .await
+        .expect("kill");
     assert_eq!(mock.session_count(), 0);
 }

crates/maestro-daemon/src/cli.rs

@@ -56,6 +56,9 @@ async fn run(config_override: Option<PathBuf>) -> Result<(), Box<dyn Error>> {
         Some(p) => Tmux::new().with_tmpdir(p),
         None => Tmux::new(),
     };
+    let retained = std::sync::Arc::new(crate::retained_store::RetainedStore::new(
+        config.retained_worktree_dir(),
+    ));
     let manager = SessionManager::new_with_replay(
         std::sync::Arc::new(tmux),
         sidecar,
@@ -66,7 +69,10 @@ async fn run(config_override: Option<PathBuf>) -> Result<(), Box<dyn Error>> {
     .with_spawn_history(crate::spawn_history::SpawnHistory::new(
         config.spawn_history_path(),
         config.spawn_history_days,
-    ));
+    ))
+    // One store instance shared with the API handlers: forced kills (#81)
+    // record here, `GET /api/worktrees` (#80) reads back from here.
+    .with_retained_store((*retained).clone());
 
     let recovered = manager.recover().await?;
     tracing::info!(recovered, "adopted existing tmux sessions");
@@ -85,6 +91,7 @@ async fn run(config_override: Option<PathBuf>) -> Result<(), Box<dyn Error>> {
         config.home_dir.clone(),
         config.spawn_presets.clone(),
         projects,
+        retained,
     ));
 
     let listener = TcpListener::bind(config.bind_addr).await?;

crates/maestro-daemon/src/config.rs

@@ -103,6 +103,11 @@ impl DaemonConfig {
     pub fn spawn_history_path(&self) -> PathBuf {
         self.state_dir.join("spawn-history.jsonl")
     }
+
+    /// Retained-worktree store directory (#78): `<state_dir>/retained-worktrees/`.
+    pub fn retained_worktree_dir(&self) -> PathBuf {
+        self.state_dir.join("retained-worktrees")
+    }
 }
 
 /// Env-var overrides applied by [`load_config`]. Tests pass explicit

crates/maestro-daemon/src/dirlist.rs

@@ -111,6 +111,7 @@ fn io_error(dir: &Path, e: &std::io::Error) -> ErrorInfo {
     ErrorInfo {
         code: code.into(),
         message: format!("{message}: {}", dir.display()),
+        unsaved_work: None,
     }
 }
 

crates/maestro-daemon/src/lib.rs

@@ -19,11 +19,13 @@ pub mod panes;
 pub mod proc;
 pub mod projects;
 pub mod pty;
+pub mod retained_store;
 pub mod session;
 pub mod sidecar;
 pub mod spawn_history;
 pub mod tmux;
 pub mod worktree;
+pub mod worktree_probe;
 
 pub use config::{default_config_path, default_state_dir, load_config, DaemonConfig, EnvOverrides};
 pub use session::{SessionError, SessionManager};

crates/maestro-daemon/src/local_api.rs

@@ -38,6 +38,9 @@ pub struct LocalApiState {
     pub presets: Arc<Vec<SpawnPreset>>,
     /// Project discovery (#54) backing `GET /api/projects`.
     pub projects: Arc<crate::projects::ProjectScanner>,
+    /// Retained worktrees (#78) backing `GET /api/worktrees` and their
+    /// reclaim endpoint (#80).
+    pub retained: Arc<crate::retained_store::RetainedStore>,
 }
 
 pub fn router(state: LocalApiState) -> Router {
@@ -50,6 +53,8 @@ pub fn router(state: LocalApiState) -> Router {
         .route(routes::GITROOT, get(git_root))
         .route(routes::BRANCHES, get(crate::branches::handler))
         .route(routes::NAMES, get(names))
+        .route(routes::WORKTREES, get(list_worktrees))
+        .route(routes::patterns::WORKTREE, delete(reclaim_worktree))
         .route(routes::INFO, get(daemon_info))
         .route(routes::EVENTS, any(events_ws))
         .route(routes::patterns::ATTACH, any(attach_ws))
@@ -94,6 +99,10 @@ fn session_error_status(code: &str) -> StatusCode {
     match code {
         "not_found" => StatusCode::NOT_FOUND,
         "invalid_env" => StatusCode::BAD_REQUEST,
+        // A guard refusal is the daemon doing its job, not a failure (#79).
+        "kill_guarded" => StatusCode::CONFLICT,
+        // The retention record failed before anything was torn down (#81).
+        "retain_failed" => StatusCode::INTERNAL_SERVER_ERROR,
         _ => StatusCode::BAD_GATEWAY,
     }
 }
@@ -168,17 +177,144 @@ async fn create_session(
 /// `kill` already reports a missing session as `SessionError::NotFound`, which
 /// maps to 404. Checking first would only add a window in which the liveness
 /// watcher reaps the session between the two awaits, turning a 404 into a 502.
-async fn kill_session(State(s): State<LocalApiState>, Path(id): Path<Uuid>) -> Response {
-    match s.manager.kill(id).await {
-        Ok(()) => StatusCode::NO_CONTENT.into_response(),
+///
+/// The full error info is passed through rather than rebuilt from
+/// code + message: a `kill_guarded` refusal (#79) carries the unsaved-work
+/// breakdown clients render as "3 uncommitted files, 2 unpushed commits".
+///
+/// With `force=true` (#81) the refusal is overridden and the worktree
+/// retained; the answer is `200` with a [`KillOutcome`] naming what was kept.
+/// Without it the historical `204` stands.
+#[derive(Debug, Deserialize)]
+struct KillQuery {
+    #[serde(default)]
+    force: bool,
+}
+
+async fn kill_session(
+    State(s): State<LocalApiState>,
+    Path(id): Path<Uuid>,
+    Query(q): Query<KillQuery>,
+) -> Response {
+    match s.manager.kill(id, q.force).await {
+        Ok(outcome) => {
+            if q.force {
+                (StatusCode::OK, Json(outcome)).into_response()
+            } else {
+                StatusCode::NO_CONTENT.into_response()
+            }
+        }
         Err(e) => {
             let info = e.to_error_info();
-            error_response(
-                session_error_status(&info.code),
-                info.code.as_str(),
-                info.message.as_str(),
+            let status = session_error_status(&info.code);
+            (status, Json(ApiError { error: info })).into_response()
+        }
+    }
+}
+
+/// `GET /api/worktrees` (#80): every retained worktree, with the in-the-way
+/// breakdown recomputed at read time — never stored, so a tree whose work has
+/// since been committed or pushed says so. Entries whose directory somebody
+/// removed by hand are pruned on the way through.
+async fn list_worktrees(State(s): State<LocalApiState>) -> Response {
+    let retained = s.retained.clone();
+    let listed = tokio::task::spawn_blocking(move || {
+        retained.prune_missing()?;
+        retained
+            .load_all()?
+            .iter()
+            .map(|entry| {
+                // A tree git cannot read (permissions, corrupt checkout)
+                // still gets listed; it just reports nothing in the way.
+                let in_the_way = crate::worktree_probe::in_the_way(&entry.path).unwrap_or_default();
+                Ok(maestro_protocol::RetainedWorktree {
+                    id: entry.id,
+                    path: entry.path.clone(),
+                    base_repo: entry.base_repo.clone(),
+                    branch: entry.branch.clone(),
+                    reason: entry.reason,
+                    retained_at: entry.retained_at,
+                    in_the_way,
+                })
+            })
+            .collect::<Result<Vec<_>, crate::retained_store::RetainedStoreError>>()
+    })
+    .await;
+    match listed {
+        Ok(Ok(worktrees)) => Json(worktrees).into_response(),
+        Ok(Err(e)) => error_response(
+            StatusCode::INTERNAL_SERVER_ERROR,
+            "store_failed",
+            &e.to_string(),
+        ),
+        Err(e) => error_response(
+            StatusCode::INTERNAL_SERVER_ERROR,
+            "join_failed",
+            &e.to_string(),
+        ),
+    }
+}
+
+/// `DELETE /api/worktrees/:id` (#80): reclaim one retained worktree. Removes
+/// the directory and drops the store entry, without consulting the guard —
+/// reclaim is the deliberate destructive act, chosen while looking at what is
+/// in the way. The branch itself is never deleted; commits on it survive.
+async fn reclaim_worktree(State(s): State<LocalApiState>, Path(id): Path<Uuid>) -> Response {
+    let found = {
+        let retained = s.retained.clone();
+        tokio::task::spawn_blocking(move || -> Result<
+            Option<crate::retained_store::RetainedWorktreeRecord>,
+            crate::retained_store::RetainedStoreError,
+        > {
+            Ok(retained.load_all()?.into_iter().find(|e| e.id == id))
+        })
+        .await
+    };
+    let entry = match found {
+        Ok(Ok(Some(entry))) => entry,
+        Ok(Ok(None)) => {
+            return error_response(
+                StatusCode::NOT_FOUND,
+                "not_found",
+                "no such retained worktree",
             )
         }
+        Ok(Err(e)) => {
+            return error_response(
+                StatusCode::INTERNAL_SERVER_ERROR,
+                "store_failed",
+                &e.to_string(),
+            )
+        }
+        Err(e) => {
+            return error_response(
+                StatusCode::INTERNAL_SERVER_ERROR,
+                "join_failed",
+                &e.to_string(),
+            )
+        }
+    };
+
+    let outcome = {
+        let retained = s.retained.clone();
+        tokio::task::spawn_blocking(move || -> Result<(), String> {
+            crate::worktree_probe::reclaim(&entry.base_repo, &entry.path)
+                .map_err(|e| e.to_string())?;
+            retained.remove(id).map_err(|e| e.to_string())?;
+            Ok(())
+        })
+        .await
+    };
+    match outcome {
+        Ok(Ok(())) => StatusCode::NO_CONTENT.into_response(),
+        // The directory could not be removed: leave the entry so the
+        // operator still sees the tree and can retry.
+        Ok(Err(e)) => error_response(StatusCode::BAD_GATEWAY, "reclaim_failed", &e.to_string()),
+        Err(e) => error_response(
+            StatusCode::INTERNAL_SERVER_ERROR,
+            "join_failed",
+            &e.to_string(),
+        ),
     }
 }
 
@@ -197,6 +333,7 @@ pub fn state_for(
     home_dir: impl Into<String>,
     presets: Vec<SpawnPreset>,
     projects: Arc<crate::projects::ProjectScanner>,
+    retained: Arc<crate::retained_store::RetainedStore>,
 ) -> LocalApiState {
     LocalApiState {
         manager,
@@ -204,6 +341,7 @@ pub fn state_for(
         home_dir: Arc::new(home_dir.into()),
         presets: Arc::new(presets),
         projects,
+        retained,
     }
 }
 

crates/maestro-daemon/src/projects.rs

@@ -261,6 +261,8 @@ impl ProjectScanner {
     }
 
     /// Cached snapshot, rescanning (off-thread) when the TTL has lapsed.
+    /// Also the background timer's entry point: a tick inside the TTL is a
+    /// no-op (#75).
     pub async fn repos(&self) -> std::sync::Arc<Vec<DiscoveredRepo>> {
         let mut cache = self.cache.lock().await;
         if let Some((at, repos)) = cache.as_ref() {
@@ -281,7 +283,9 @@ impl ProjectScanner {
         repos
     }
 
-    /// Rescan now, ignoring the TTL. Called by the background timer.
+    /// One background-refresh tick: rescan only if the cached snapshot has
+    /// passed its TTL (#75) — the timer used to bypass it and re-walk the
+    /// roots every [`REFRESH_INTERVAL`].
     async fn refresh(&self) {
         self.repos().await;
     }
@@ -536,6 +540,32 @@ mod tests {
         assert_eq!(fresh[0].name, "late");
     }
 
+    #[tokio::test]
+    async fn background_refresh_honours_the_ttl() {
+        let tmp = tempfile::tempdir().unwrap();
+        let mut scanner = ProjectScanner::new(
+            vec![tmp.path().to_path_buf()],
+            3,
+            PathBuf::from("/nonexistent"),
+        );
+
+        let empty = scanner.repos().await;
+        assert!(empty.is_empty());
+
+        make_repo(tmp.path(), "late");
+        // A background tick inside the TTL must not re-walk the filesystem:
+        // the new repo stays invisible until the cache expires.
+        scanner.refresh().await;
+        assert!(scanner.repos().await.is_empty());
+
+        // Once the TTL lapses, the next tick picks it up.
+        scanner.ttl = Duration::ZERO;
+        scanner.refresh().await;
+        let fresh = scanner.repos().await;
+        assert_eq!(fresh.len(), 1);
+        assert_eq!(fresh[0].name, "late");
+    }
+
     #[test]
     fn disabled_scanner_always_serves_empty() {
         let scanner = ProjectScanner::disabled();

crates/maestro-daemon/src/retained_store.rs

@@ -0,0 +1,310 @@
+//! Store of retained worktrees (#78): worktrees the daemon created whose
+//! session is gone.
+//!
+//! One JSON file per entry under `<state_dir>/retained-worktrees/`, written
+//! the way `sidecar.rs` writes session records — atomic tmp+rename replace,
+//! missing or malformed files tolerated on read. The store survives a daemon
+//! restart; it is the recovery path for everything else in the worktree
+//! lifecycle.
+//!
+//! It is not an ownership record: it must never be consulted to decide whether
+//! a path may be adopted. Its only job is to remember what the daemon is
+//! holding so it can be listed and reclaimed.
+
+use std::path::{Path, PathBuf};
+
+use chrono::{DateTime, Utc};
+/// Why a worktree outlived its session — [`maestro_protocol::RetainedReason`],
+/// so the store and the wire payload cannot drift apart.
+pub use maestro_protocol::RetainedReason;
+use uuid::Uuid;
+
+#[derive(Debug, thiserror::Error)]
+pub enum RetainedStoreError {
+    #[error("io: {0}")]
+    Io(#[from] std::io::Error),
+    #[error("json: {0}")]
+    Json(#[from] serde_json::Error),
+}
+
+#[derive(Debug, Clone, PartialEq, serde::Serialize, serde::Deserialize)]
+pub struct RetainedWorktreeRecord {
+    pub id: Uuid,
+    pub path: PathBuf,
+    pub base_repo: PathBuf,
+    pub branch: String,
+    pub reason: RetainedReason,
+    pub retained_at: DateTime<Utc>,
+}
+
+#[derive(Debug, Clone)]
+pub struct RetainedStore {
+    dir: PathBuf,
+}
+
+impl RetainedStore {
+    pub fn new(dir: impl Into<PathBuf>) -> Self {
+        Self { dir: dir.into() }
+    }
+
+    pub fn dir(&self) -> &Path {
+        &self.dir
+    }
+
+    fn path_for(&self, id: Uuid) -> PathBuf {
+        self.dir.join(format!("{id}.json"))
+    }
+
+    /// Record a retained worktree and return the entry that was written.
+    pub fn retain(
+        &self,
+        path: &Path,
+        base_repo: &Path,
+        branch: &str,
+        reason: RetainedReason,
+    ) -> Result<RetainedWorktreeRecord, RetainedStoreError> {
+        let entry = RetainedWorktreeRecord {
+            id: Uuid::new_v4(),
+            path: path.to_path_buf(),
+            base_repo: base_repo.to_path_buf(),
+            branch: branch.to_string(),
+            reason,
+            retained_at: Utc::now(),
+        };
+        self.overwrite(&entry)?;
+        Ok(entry)
+    }
+
+    /// Atomically write `entry`. Creates the directory if it does not exist.
+    pub fn overwrite(&self, entry: &RetainedWorktreeRecord) -> Result<(), RetainedStoreError> {
+        std::fs::create_dir_all(&self.dir)?;
+        let final_path = self.path_for(entry.id);
+        let tmp = self.dir.join(format!("{}.json.tmp", entry.id));
+        let json = serde_json::to_vec_pretty(entry)?;
+        std::fs::write(&tmp, json)?;
+        std::fs::rename(&tmp, &final_path)?;
+        Ok(())
+    }
+
+    /// Drop one entry. No-op when the id is unknown — reclaiming an entry the
+    /// store already lost (e.g. pruned) must not fail.
+    pub fn remove(&self, id: Uuid) -> Result<(), RetainedStoreError> {
+        match std::fs::remove_file(self.path_for(id)) {
+            Ok(()) => Ok(()),
+            Err(e) if e.kind() == std::io::ErrorKind::NotFound => Ok(()),
+            Err(e) => Err(e.into()),
+        }
+    }
+
+    /// Read every entry. Files that are missing or malformed are skipped
+    /// silently: a corrupt record must not hide the others, and an empty or
+    /// absent directory simply means nothing is retained.
+    pub fn load_all(&self) -> Result<Vec<RetainedWorktreeRecord>, RetainedStoreError> {
+        let mut out = Vec::new();
+        let entries = match std::fs::read_dir(&self.dir) {
+            Ok(e) => e,
+            Err(e) if e.kind() == std::io::ErrorKind::NotFound => return Ok(out),
+            Err(e) => return Err(e.into()),
+        };
+        for entry in entries {
+            let entry = entry?;
+            let path = entry.path();
+            if path.extension().and_then(|s| s.to_str()) != Some("json") {
+                continue;
+            }
+            let Ok(bytes) = std::fs::read(&path) else {
+                continue;
+            };
+            if let Ok(worktree) = serde_json::from_slice::<RetainedWorktreeRecord>(&bytes) {
+                out.push(worktree);
+            }
+        }
+        out.sort_by_key(|w| w.retained_at);
+        Ok(out)
+    }
+
+    /// Drop entries whose worktree directory no longer exists — somebody
+    /// removed it by hand. Returns the ids that were pruned.
+    pub fn prune_missing(&self) -> Result<Vec<Uuid>, RetainedStoreError> {
+        let mut pruned = Vec::new();
+        for entry in self.load_all()? {
+            if !entry.path.exists() {
+                self.remove(entry.id)?;
+                pruned.push(entry.id);
+            }
+        }
+        Ok(pruned)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use chrono::Duration;
+    use std::path::PathBuf;
+
+    fn tmp_dir() -> tempfile::TempDir {
+        tempfile::tempdir().expect("tempdir")
+    }
+
+    fn sample_path(root: &std::path::Path, name: &str) -> PathBuf {
+        let p = root.join(name);
+        std::fs::create_dir_all(&p).expect("mkdir");
+        p
+    }
+
+    #[test]
+    fn retain_then_load_round_trips_every_field() {
+        let dir = tmp_dir();
+        let store = RetainedStore::new(dir.path());
+        let wt = sample_path(dir.path(), "wt");
+        let repo = sample_path(dir.path(), "repo");
+
+        let entry = store
+            .retain(&wt, &repo, "feature/login", RetainedReason::ForceKilled)
+            .expect("retain");
+
+        let all = store.load_all().expect("load_all");
+        assert_eq!(all, vec![entry.clone()]);
+        assert_eq!(entry.path, wt);
+        assert_eq!(entry.base_repo, repo);
+        assert_eq!(entry.branch, "feature/login");
+        assert_eq!(entry.reason, RetainedReason::ForceKilled);
+        let age = Utc::now() - entry.retained_at;
+        assert!(age >= Duration::zero() && age < Duration::minutes(1));
+    }
+
+    #[test]
+    fn reason_serializes_kebab_case() {
+        let json =
+            serde_json::to_string(&RetainedReason::ExitedWithUnsavedWork).expect("serialize");
+        assert_eq!(json, r#""exited-with-unsaved-work""#);
+    }
+
+    #[test]
+    fn entries_survive_a_restart() {
+        let dir = tmp_dir();
+        let wt = sample_path(dir.path(), "wt");
+
+        let first = RetainedStore::new(dir.path());
+        let entry = first
+            .retain(&wt, dir.path(), "main", RetainedReason::ForceKilled)
+            .expect("retain");
+
+        // A fresh store over the same state_dir — what a daemon restart sees.
+        let second = RetainedStore::new(dir.path());
+        assert_eq!(second.load_all().expect("load_all"), vec![entry]);
+    }
+
+    #[test]
+    fn missing_store_reads_as_empty() {
+        let dir = tmp_dir();
+        let store = RetainedStore::new(dir.path().join("does-not-exist"));
+        assert_eq!(store.load_all().expect("load_all"), Vec::new());
+    }
+
+    #[test]
+    fn malformed_entries_are_skipped_silently() {
+        let dir = tmp_dir();
+        let store = RetainedStore::new(dir.path());
+        let wt = sample_path(dir.path(), "wt");
+        store
+            .retain(&wt, dir.path(), "kept", RetainedReason::ForceKilled)
+            .expect("retain");
+        std::fs::write(dir.path().join("not-a-uuid.json"), b"{oops").expect("write junk");
+
+        let all = store.load_all().expect("load_all");
+        assert_eq!(all.len(), 1);
+        assert_eq!(all[0].branch, "kept");
+    }
+
+    #[test]
+    fn ids_are_unique() {
+        let dir = tmp_dir();
+        let store = RetainedStore::new(dir.path());
+        let a = store
+            .retain(dir.path(), dir.path(), "a", RetainedReason::ForceKilled)
+            .expect("retain");
+        let b = store
+            .retain(dir.path(), dir.path(), "b", RetainedReason::ForceKilled)
+            .expect("retain");
+        assert_ne!(a.id, b.id);
+    }
+
+    #[test]
+    fn remove_drops_the_entry() {
+        let dir = tmp_dir();
+        let store = RetainedStore::new(dir.path());
+        let wt = sample_path(dir.path(), "wt");
+        let entry = store
+            .retain(&wt, dir.path(), "main", RetainedReason::ForceKilled)
+            .expect("retain");
+
+        store.remove(entry.id).expect("remove");
+        assert_eq!(store.load_all().expect("load_all"), Vec::new());
+
+        // Removing an unknown id is a no-op, not an error.
+        store.remove(entry.id).expect("remove again");
+    }
+
+    #[test]
+    fn load_all_is_sorted_by_time() {
+        let dir = tmp_dir();
+        let store = RetainedStore::new(dir.path());
+        let mut first = store
+            .retain(dir.path(), dir.path(), "first", RetainedReason::ForceKilled)
+            .expect("retain");
+        first.retained_at -= Duration::hours(1);
+        store.overwrite(&first).expect("rewrite");
+
+        let second = store
+            .retain(
+                dir.path(),
+                dir.path(),
+                "second",
+                RetainedReason::ForceKilled,
+            )
+            .expect("retain");
+
+        let branches: Vec<_> = store
+            .load_all()
+            .expect("load_all")
+            .into_iter()
+            .map(|e| e.branch)
+            .collect();
+        assert_eq!(branches, vec!["first", "second"]);
+        let _ = second;
+    }
+
+    #[test]
+    fn prune_missing_drops_gone_directories_only() {
+        let dir = tmp_dir();
+        let store = RetainedStore::new(dir.path());
+        let alive = sample_path(dir.path(), "alive");
+        let gone = sample_path(dir.path(), "gone");
+        let keep = store
+            .retain(&alive, dir.path(), "keep", RetainedReason::ForceKilled)
+            .expect("retain");
+        let drop = store
+            .retain(
+                &gone,
+                dir.path(),
+                "drop",
+                RetainedReason::ExitedWithUnsavedWork,
+            )
+            .expect("retain");
+        std::fs::remove_dir_all(&gone).expect("rm");
+
+        let pruned = store.prune_missing().expect("prune_missing");
+        assert_eq!(pruned, vec![drop.id]);
+
+        let branches: Vec<_> = store
+            .load_all()
+            .expect("load_all")
+            .into_iter()
+            .map(|e| e.branch)
+            .collect();
+        assert_eq!(branches, vec!["keep"]);
+        let _ = keep;
+    }
+}

crates/maestro-daemon/src/session.rs

@@ -12,8 +12,8 @@ use std::time::Duration;
 
 use chrono::Utc;
 use maestro_protocol::{
-    ActivityState, CatalogEvent, CreateSessionRequest, ErrorInfo, Session, SessionStatus,
-    WorktreeSpec,
+    ActivityState, CatalogEvent, CreateSessionRequest, ErrorInfo, KillOutcome, RetainedReason,
+    RetainedWorktree, Session, SessionStatus, WorktreeSpec,
 };
 use tokio::sync::{broadcast, Mutex};
 use uuid::Uuid;
@@ -33,17 +33,29 @@ pub const EVENTS_CAPACITY: usize = maestro_config::EVENTS_CAPACITY;
 /// How often the liveness watcher polls tmux for sessions that disappeared.
 pub const DEFAULT_LIVENESS_INTERVAL: Duration = Duration::from_secs(2);
 
+/// How often the liveness watcher re-probes worktrees for the blocked-work
+/// indicator (#83). Each probe costs three git subprocesses per session, so
+/// the pass rides the same tick as everything else but runs on a slower
+/// cadence: an indicator a few seconds stale still warns before the kill
+/// attempt, which is all #83 needs.
+pub const DEFAULT_BLOCKED_WORK_INTERVAL: Duration = Duration::from_secs(15);
+
 /// Per-session daemon-local bookkeeping that complements the public `Session`.
 #[derive(Debug)]
 pub struct SessionRecord {
     pub session: Session,
     pub fifo_path: PathBuf,
-    /// Worktree we created at spawn time; removed on kill unless the
-    /// dirty-work guard refuses (#56).
+    /// Worktree we created at spawn time; removed on kill, but only after the
+    /// kill guard (#79) found nothing worth keeping in it.
     pub worktree_path: Option<PathBuf>,
     /// `base_repo` from the original `WorktreeSpec`. Needed because `git
     /// worktree remove` is invoked from the base repo.
     pub worktree_base_repo: Option<PathBuf>,
+    /// Branch the worktree was created for, recorded at spawn time so a
+    /// forced kill (#81) can name it in the retained store without asking
+    /// git. Sessions adopted from a sidecar have no branch on record and
+    /// fall back to a probe.
+    pub worktree_branch: Option<String>,
     pub bridge: PtyBridge,
 }
 
@@ -61,6 +73,16 @@ pub enum SessionError {
     NotFound(Uuid),
     #[error("invalid environment variable name: {0:?}")]
     InvalidEnv(String),
+    /// The kill was refused (#79): the session's worktree holds unsaved work.
+    /// Nothing happened — the session keeps running and the tree is untouched,
+    /// so it stays the operator's handle on their own unfinished work.
+    #[error("kill refused: the session's worktree holds unsaved work ({0})")]
+    KillGuarded(maestro_protocol::InTheWay),
+    /// A forced kill (#81) records the retained worktree *before* tearing
+    /// anything down; if that write fails nothing was destroyed, and the
+    /// error says so rather than silently dropping unrecorded work.
+    #[error("could not record the retained worktree: {0}")]
+    RetainFailed(String),
 }
 
 impl SessionError {
@@ -72,10 +94,17 @@ impl SessionError {
             SessionError::Io(_) => "io_failed",
             SessionError::NotFound(_) => "not_found",
             SessionError::InvalidEnv(_) => "invalid_env",
+            SessionError::KillGuarded(_) => "kill_guarded",
+            SessionError::RetainFailed(_) => "retain_failed",
+        };
+        let unsaved_work = match self {
+            SessionError::KillGuarded(b) => Some(*b),
+            _ => None,
         };
         ErrorInfo {
             code: code.into(),
             message: self.to_string(),
+            unsaved_work,
         }
     }
 }
@@ -99,6 +128,9 @@ struct Inner {
     /// `None` when not wired (tests, or before `with_spawn_history`); a present
     /// but disabled (`0`-day) history no-ops internally.
     spawn_history: Option<SpawnHistory>,
+    /// Retained-worktree store (#78). `None` when not wired (tests); a forced
+    /// kill (#81) without one fails rather than destroying unrecorded work.
+    retained: Option<crate::retained_store::RetainedStore>,
     sessions: Mutex<HashMap<Uuid, SessionRecord>>,
     events: broadcast::Sender<CatalogEvent>,
 }
@@ -137,6 +169,7 @@ impl SessionManager {
                 fifo_dir,
                 replay_bytes,
                 spawn_history: None,
+                retained: None,
                 sessions: Mutex::new(HashMap::new()),
                 events,
             }),
@@ -159,6 +192,16 @@ impl SessionManager {
         self
     }
 
+    /// Attach the retained-worktree store (#78). A forced kill (#81) needs it
+    /// to record what it retained; without one, forcing a guarded kill fails
+    /// instead of destroying unrecorded work.
+    pub fn with_retained_store(mut self, store: crate::retained_store::RetainedStore) -> Self {
+        let inner = Arc::get_mut(&mut self.inner)
+            .expect("with_retained_store must be called before the SessionManager is cloned");
+        inner.retained = Some(store);
+        self
+    }
+
     /// Recent working dirs for the spawn form's picker (#24), newest-first and
     /// deduped by dir. Empty when no history is wired or it's disabled.
     pub fn recent_dirs(&self) -> Vec<RecentDir> {
@@ -226,6 +269,9 @@ impl SessionManager {
                 let WorktreeSpec {
                     base_repo, branch, ..
                 } = spec;
+                // A path collision is sidestepped inside `run_add` (#77), and
+                // a branch already checked out elsewhere is git's refusal,
+                // not ours.
                 let path = if spec.create_branch {
                     self.inner.worktree_mgr.add_new(base_repo, branch)
                 } else {
@@ -290,6 +336,12 @@ impl SessionManager {
             command: req.command,
             env: req.env,
             metadata: req.metadata,
+            worktree: worktree_path.as_ref().zip(worktree_base_repo.as_ref()).map(
+                |(path, base_repo)| maestro_protocol::SessionWorktree {
+                    path: path.clone(),
+                    base_repo: base_repo.clone(),
+                },
+            ),
             status: SessionStatus::Running,
             created_at: Utc::now(),
             // A freshly-spawned session is producing its initial output; the
@@ -299,6 +351,9 @@ impl SessionManager {
             last_activity_at: Utc::now(),
 
             current_cwd: None,
+            // The watcher fills this in on its first blocked-work pass; a
+            // fresh tree has nothing in the way anyway.
+            blocked_work: None,
         };
 
         if let Err(e) = self.inner.sidecar.write(&session) {
@@ -320,6 +375,7 @@ impl SessionManager {
                     fifo_path,
                     worktree_path,
                     worktree_base_repo,
+                    worktree_branch: req.worktree.as_ref().map(|w| w.branch.clone()),
                     bridge,
                 },
             );
@@ -361,22 +417,78 @@ impl SessionManager {
         }
     }
 
-    /// Kill a session and remove its on-disk artifacts. The worktree is
-    /// always pruned -- unless it holds uncommitted changes or commits not on
-    /// any other ref, in which case the guard leaves it on disk (#56).
+    /// Kill a session and remove its on-disk artifacts.
+    ///
+    /// Refused (#79) when the session's worktree holds unsaved work —
+    /// uncommitted tracked changes, untracked non-ignored files, or commits
+    /// reachable from no remote-tracking ref. Nothing is killed and nothing
+    /// is removed; the error names what blocked it and how much of it there
+    /// is. The session stays as the operator's handle on their own unfinished
+    /// work, so ending a session that still matters becomes a deliberate
+    /// `--force`, which retains rather than destroys (WORKTREES.md).
+    ///
+    /// With `force` (#81) the refusal — and nothing else — is overridden:
+    /// the session ends and the guarded worktree is retained into the store
+    /// with reason `force-killed`, never removed. The outcome names what was
+    /// kept so a client can say where the work went. A tree whose guard is
+    /// clear never needed the override; force removes it as usual.
     ///
     /// This is also how an already-dead session is dismissed. tmux is only
     /// asked to kill something it still has — calling `kill-session` on a
     /// session tmux already lost fails, and that failure is not interesting.
-    pub async fn kill(&self, id: Uuid) -> Result<(), SessionError> {
+    pub async fn kill(&self, id: Uuid, force: bool) -> Result<KillOutcome, SessionError> {
+        let (worktree, alive, known_branch) = {
+            let sessions = self.inner.sessions.lock().await;
+            match sessions.get(&id) {
+                None => return Err(SessionError::NotFound(id)),
+                Some(record) => (
+                    record
+                        .worktree_base_repo
+                        .clone()
+                        .zip(record.worktree_path.clone()),
+                    record.session.status == SessionStatus::Running,
+                    record.worktree_branch.clone(),
+                ),
+            }
+        };
+        let probe = match &worktree {
+            Some(wt) => Some(probe_worktree(wt).await?),
+            None => None,
+        };
+        let guarded = probe.as_ref().is_some_and(|p| !p.is_clear());
+        if guarded && !force {
+            return Err(SessionError::KillGuarded(probe.expect("guarded ⇒ probed")));
+        }
+
+        let mut retained = None;
+        if guarded {
+            let entry = record_retention(
+                &self.inner,
+                worktree.as_ref().expect("guarded ⇒ worktree"),
+                known_branch,
+                RetainedReason::ForceKilled,
+            )
+            .await?;
+            retained = Some((entry, probe.expect("guarded ⇒ probed")));
+        }
+
         let removed = {
             let mut sessions = self.inner.sessions.lock().await;
             sessions.remove(&id)
         };
         let record = removed.ok_or(SessionError::NotFound(id))?;
-        let alive = record.session.status == SessionStatus::Running;
-        cleanup_record(&self.inner, id, record, alive).await;
-        Ok(())
+        cleanup_record(&self.inner, id, record, alive, retained.is_some()).await;
+        Ok(KillOutcome {
+            retained: retained.map(|(entry, in_the_way)| RetainedWorktree {
+                id: entry.id,
+                path: entry.path,
+                base_repo: entry.base_repo,
+                branch: entry.branch,
+                reason: entry.reason,
+                retained_at: entry.retained_at,
+                in_the_way,
+            }),
+        })
     }
 
     /// Spawn a background task that polls tmux every `interval` and reaps any
@@ -387,6 +499,17 @@ impl SessionManager {
     /// `SessionManager` clone is dropped — call this once from the daemon
     /// startup path after [`Self::recover`] has populated the map.
     pub fn start_liveness_watcher(&self, interval: Duration) {
+        self.start_liveness_watcher_with_blocked_work(interval, DEFAULT_BLOCKED_WORK_INTERVAL);
+    }
+
+    /// [`Self::start_liveness_watcher`] with the blocked-work cadence (#83)
+    /// made explicit. Tests pass a small `blocked_work_interval` to watch the
+    /// probe actually happen.
+    pub fn start_liveness_watcher_with_blocked_work(
+        &self,
+        interval: Duration,
+        blocked_work_interval: Duration,
+    ) {
         let weak = Arc::downgrade(&self.inner);
         tokio::spawn(async move {
             let mut ticker = tokio::time::interval(interval);
@@ -394,6 +517,9 @@ impl SessionManager {
             // first tick fires immediately — skip it so we don't reap before
             // the caller has a chance to create anything.
             ticker.tick().await;
+            // Start "due" so the first live tick probes: a recovered daemon
+            // should not wait a full interval to show what blocks.
+            let mut since_probe = blocked_work_interval;
             loop {
                 ticker.tick().await;
                 let Some(inner) = weak.upgrade() else {
@@ -403,6 +529,11 @@ impl SessionManager {
                 // Same tick, no new timer (NAP-340): refresh activity for the
                 // survivors and emit SessionUpdated on any transition.
                 run_activity_pass(&inner).await;
+                since_probe += interval;
+                if since_probe >= blocked_work_interval {
+                    since_probe = Duration::ZERO;
+                    run_blocked_work_pass(&inner).await;
+                }
             }
         });
     }
@@ -430,6 +561,7 @@ impl SessionManager {
                     command: String::new(),
                     env: Default::default(),
                     metadata: Default::default(),
+                    worktree: None,
                     status: SessionStatus::Running,
                     created_at: Utc::now(),
                     // Activity is unknown on adoption; the watcher fills it in.
@@ -438,6 +570,7 @@ impl SessionManager {
                     last_activity_at: Utc::now(),
 
                     current_cwd: None,
+                    blocked_work: None,
                 },
             };
             let fifo_path = self.inner.fifo_dir.join(format!("{id}.fifo"));
@@ -457,8 +590,14 @@ impl SessionManager {
                 SessionRecord {
                     session: session.clone(),
                     fifo_path,
-                    worktree_path: None,
-                    worktree_base_repo: None,
+                    // Restored from the sidecar: without it the recovered
+                    // session cleans up nothing on kill, and the leftover
+                    // directory blocks that branch forever (#54 review).
+                    worktree_path: session.worktree.as_ref().map(|w| w.path.clone()),
+                    worktree_base_repo: session.worktree.as_ref().map(|w| w.base_repo.clone()),
+                    // The sidecar carries no branch; a forced kill of a
+                    // recovered session probes git for it at retain time.
+                    worktree_branch: None,
                     bridge,
                 },
             );
@@ -535,6 +674,49 @@ where
         .expect("tmux blocking task panicked")
 }
 
+/// What would be lost if this session's worktree were removed right now.
+///
+/// The single [`crate::worktree_probe::in_the_way`] call site behind both
+/// endings of a session — the kill guard (#79) and the natural-exit
+/// classifier (#82) — so neither can grow its own answer. Runs on the
+/// blocking pool; callers invoke it before anything is torn down, because
+/// refusing (#79), recording a retention (#81) and classifying an exit (#82)
+/// must all see the tree as it stands.
+async fn probe_worktree(
+    (_, path): &(PathBuf, PathBuf),
+) -> Result<maestro_protocol::InTheWay, SessionError> {
+    let path = path.clone();
+    tmux_blocking(move || crate::worktree_probe::in_the_way(&path))
+        .await
+        .map_err(|e| SessionError::Worktree(crate::worktree::WorktreeError::from(e)))
+}
+
+/// Record a guarded worktree into the retained store with `reason`, BEFORE
+/// the caller tears anything down: a failed write then leaves every artifact
+/// untouched instead of destroying work nothing records anymore. Shared by
+/// the forced kill (`ForceKilled`, #81) and the natural exit
+/// (`ExitedWithUnsavedWork`, #82) so the two paths cannot drift apart.
+async fn record_retention(
+    inner: &Arc<Inner>,
+    (base_repo, path): &(PathBuf, PathBuf),
+    known_branch: Option<String>,
+    reason: RetainedReason,
+) -> Result<crate::retained_store::RetainedWorktreeRecord, SessionError> {
+    let store = inner
+        .retained
+        .clone()
+        .ok_or_else(|| SessionError::RetainFailed("no retained store is wired".into()))?;
+    // Sessions adopted from a sidecar carry no branch; ask the tree itself.
+    let branch = known_branch
+        .or_else(|| crate::worktree_probe::current_branch(path))
+        .unwrap_or_default();
+    let base_repo = base_repo.clone();
+    let path = path.clone();
+    tmux_blocking(move || store.retain(&path, &base_repo, &branch, reason))
+        .await
+        .map_err(|e| SessionError::RetainFailed(e.to_string()))
+}
+
 /// One pass of the liveness watcher: diff the in-memory session set against
 /// the tmux-reported one, and reap anything we still track but tmux has lost.
 async fn run_liveness_pass(inner: &Arc<Inner>) {
@@ -657,18 +839,79 @@ async fn run_activity_pass(inner: &Arc<Inner>) {
     }
 }
 
+/// Refresh each running session's blocked-work indicator (#83): what its
+/// worktree holds right now that would block an unforced kill. Rides the
+/// liveness tick on its own (slower) cadence — see
+/// [`DEFAULT_BLOCKED_WORK_INTERVAL`] — because every probe is three git
+/// subprocesses per session.
+///
+/// Sessions without a worktree are filtered out BEFORE any probe: they can
+/// never block a kill, so their indicator must cost nothing at all. A failed
+/// probe keeps the previous value rather than clearing it — a transient git
+/// error must not read as "nothing blocks". Like the activity pass, this only
+/// emits `SessionUpdated` when the value actually changed.
+async fn run_blocked_work_pass(inner: &Arc<Inner>) {
+    let targets: Vec<(Uuid, (PathBuf, PathBuf))> = {
+        let sessions = inner.sessions.lock().await;
+        sessions
+            .iter()
+            .filter(|(_, r)| r.session.status == SessionStatus::Running)
+            .filter_map(|(id, r)| {
+                let wt = r.worktree_base_repo.clone().zip(r.worktree_path.clone())?;
+                Some((*id, wt))
+            })
+            .collect()
+    };
+    if targets.is_empty() {
+        return;
+    }
+
+    for (id, wt) in targets {
+        // The kill guard's own probe (#79), so the indicator can never
+        // disagree with what a kill attempt would find.
+        let breakdown = match probe_worktree(&wt).await {
+            Ok(breakdown) => breakdown,
+            Err(e) => {
+                tracing::debug!(%id, error = ?e, "blocked-work: probe failed; keeping previous value");
+                continue;
+            }
+        };
+        let updated = {
+            let mut sessions = inner.sessions.lock().await;
+            let Some(rec) = sessions.get_mut(&id) else {
+                continue;
+            };
+            if rec.session.blocked_work == Some(breakdown) {
+                None
+            } else {
+                rec.session.blocked_work = Some(breakdown);
+                Some(rec.session.clone())
+            }
+        };
+        if let Some(session) = updated {
+            let _ = inner.events.send(CatalogEvent::SessionUpdated { session });
+        }
+    }
+}
+
 /// Mark a session whose tmux session has disappeared as [`SessionStatus::Dead`]
-/// and announce it, keeping everything else intact.
+/// and settle its worktree per the natural-exit rule (#82).
 ///
 /// The record, its [`PtyBridge`] and its sidecar all survive, so a client can
 /// still attach and read the replay buffer — the last thing a crashed agent
-/// printed. Artifacts are only released when the operator dismisses the session
-/// via [`SessionManager::kill`].
+/// printed. The worktree, though, is settled right away: a pristine tree is
+/// removed, anything else is retained into the store with reason
+/// `exited-with-unsaved-work` (#82) — nobody is waiting for an answer here,
+/// so there is nothing to refuse. Once settled, the session drops its
+/// worktree reference so a later dismissal neither re-probes nor retains
+/// twice. When settling is impossible (probe or store failure) nothing is
+/// destroyed: the tree stays attached to the dead record for a later forced
+/// dismissal (#81).
 ///
 /// Dead sessions do not survive a daemon restart: [`SessionManager::recover`]
 /// adopts only what tmux still holds.
 async fn mark_session_dead(inner: &Arc<Inner>, id: Uuid) {
-    let updated = {
+    let flipped = {
         let mut sessions = inner.sessions.lock().await;
         match sessions.get_mut(&id) {
             Some(record) if record.session.status == SessionStatus::Running => {
@@ -676,19 +919,114 @@ async fn mark_session_dead(inner: &Arc<Inner>, id: Uuid) {
                 // Release anyone attached; the scrollback survives for a later
                 // attach.
                 record.bridge.seal();
-                Some(record.session.clone())
+                let session = record.session.clone();
+                let worktree = record
+                    .worktree_base_repo
+                    .clone()
+                    .zip(record.worktree_path.clone());
+                let branch = record.worktree_branch.clone();
+                Some((session, worktree, branch))
             }
             _ => None,
         }
     };
-    let Some(session) = updated else {
+    let Some((mut session, worktree, branch)) = flipped else {
         return;
     };
     tracing::info!(%id, "session vanished from tmux — marking dead");
+
+    if let Some(wt) = &worktree {
+        if settle_worktree_on_exit(inner, id, wt, branch).await {
+            // The tree is settled (removed or retained); a stale "in the
+            // way" would describe something the session no longer holds.
+            session.blocked_work = None;
+            let mut sessions = inner.sessions.lock().await;
+            if let Some(record) = sessions.get_mut(&id) {
+                record.session.worktree = None;
+                record.session.blocked_work = None;
+                record.worktree_path = None;
+                record.worktree_base_repo = None;
+                record.worktree_branch = None;
+            }
+        }
+    }
+
     let _ = inner.sidecar.write(&session);
     let _ = inner.events.send(CatalogEvent::SessionUpdated { session });
 }
 
+/// Apply the exit rule (#82) to a vanished session's worktree: probe what
+/// would be lost through the kill's own predicate, then remove a pristine
+/// tree or retain anything else under `exited-with-unsaved-work` — recorded
+/// before anything is torn down, exactly as the forced kill does (#81). A
+/// removal that fails falls back to retaining, since whatever blocked it is
+/// by definition something worth keeping.
+///
+/// Returns whether the worktree was fully accounted for. When it wasn't,
+/// nothing was destroyed and the caller keeps the reference on the record.
+async fn settle_worktree_on_exit(
+    inner: &Arc<Inner>,
+    id: Uuid,
+    (base_repo, path): &(PathBuf, PathBuf),
+    known_branch: Option<String>,
+) -> bool {
+    let probe = match probe_worktree(&(base_repo.clone(), path.clone())).await {
+        Ok(probe) => probe,
+        Err(e) => {
+            tracing::error!(
+                %id,
+                path = %path.display(),
+                error = ?e,
+                "natural exit: could not probe the worktree; leaving it untouched"
+            );
+            return false;
+        }
+    };
+    if probe.is_clear() {
+        match inner.worktree_mgr.remove(base_repo, path) {
+            Ok(()) => {
+                tracing::info!(%id, path = %path.display(), "natural exit: pristine worktree removed");
+                return true;
+            }
+            Err(e) => {
+                tracing::warn!(
+                    %id,
+                    path = %path.display(),
+                    error = ?e,
+                    "natural exit: removal failed; falling back to retention"
+                );
+            }
+        }
+    }
+    match record_retention(
+        inner,
+        &(base_repo.clone(), path.clone()),
+        known_branch,
+        RetainedReason::ExitedWithUnsavedWork,
+    )
+    .await
+    {
+        Ok(entry) => {
+            tracing::info!(
+                %id,
+                path = %path.display(),
+                entry = %entry.id,
+                "natural exit: worktree retained with unsaved work"
+            );
+            true
+        }
+        Err(e) => {
+            tracing::error!(
+                %id,
+                path = %path.display(),
+                error = ?e,
+                "natural exit: could not record the retained worktree; leaving it untouched"
+            );
+            false
+        }
+    }
+}
+
 /// Tear down a session's artifacts after it has already been removed from the
 /// live map. Shared by [`SessionManager::kill`] and [`reap_dead_session`],
 /// which previously hand-rolled the same five-step choreography and only
@@ -698,7 +1036,17 @@ async fn mark_session_dead(inner: &Arc<Inner>, id: Uuid) {
 /// gone from the authoritative in-memory map, so a stray FIFO or sidecar can't
 /// resurrect it. `kill_tmux` is `true` for an explicit kill and `false` for the
 /// liveness reaper (tmux already lost the session).
-async fn cleanup_record(inner: &Arc<Inner>, id: Uuid, record: SessionRecord, kill_tmux: bool) {
+///
+/// `retain_worktree` is `true` for a forced kill (#81) that retained the
+/// worktree instead of removing it: the store entry is already written, so
+/// only the removal is skipped.
+async fn cleanup_record(
+    inner: &Arc<Inner>,
+    id: Uuid,
+    record: SessionRecord,
+    kill_tmux: bool,
+    retain_worktree: bool,
+) {
     if kill_tmux {
         let tmux = inner.tmux.clone();
         let _ = tmux_blocking(move || tmux.kill_session(id)).await;
@@ -707,12 +1055,18 @@ async fn cleanup_record(inner: &Arc<Inner>, id: Uuid, record: SessionRecord, kil
     if let Err(e) = inner.sidecar.delete(id) {
         tracing::warn!(error = ?e, %id, "cleanup: failed to delete sidecar");
     }
-    // Cleanup is unconditional now (#56): `cleanup_on_kill` is no longer a
-    // user-facing choice. The manager's guard is what protects unsaved work --
-    // when it refuses, leave the tree on disk and say where it is so the
-    // operator can find it.
     if let (Some(base), Some(path)) = (&record.worktree_base_repo, &record.worktree_path) {
-        if let Err(e) = inner.worktree_mgr.remove(base, path) {
+        if retain_worktree {
+            tracing::info!(
+                %id,
+                path = %path.display(),
+                "forced kill: worktree retained in the store"
+            );
+        } else if let Err(e) = inner.worktree_mgr.remove(base, path) {
+            // The kill already passed the unsaved-work guard (#79), so this
+            // removal is unconditional; the manager's own nested-worktree
+            // refusal is all that can still leave a tree on disk, and it
+            // says where.
             tracing::warn!(
                 %id,
                 path = %path.display(),

crates/maestro-daemon/src/worktree.rs

@@ -10,15 +10,24 @@ pub enum WorktreeError {
     Spawn(#[from] std::io::Error),
     #[error("git exited with code {code}: {stderr}")]
     NonZero { code: i32, stderr: String },
-    /// A worktree already occupies the target path. The caller decides what
-    /// to do; the daemon never relocates to a different directory (#56).
-    #[error("worktree path already exists: {}", .path.display())]
-    PathExists { path: PathBuf },
-    /// The worktree holds unsaved work; removal was refused (#56).
+    /// A registered worktree lives under the tree about to be removed; git
+    /// hides its contents from `git status`, so removal would delete its
+    /// uncommitted work unseen (#54 review).
     #[error("left {} on disk: {}", .path.display(), .reason)]
     Guarded { path: PathBuf, reason: String },
 }
 
+impl From<crate::worktree_probe::ProbeError> for WorktreeError {
+    fn from(e: crate::worktree_probe::ProbeError) -> Self {
+        match e {
+            crate::worktree_probe::ProbeError::Spawn(io) => WorktreeError::Spawn(io),
+            crate::worktree_probe::ProbeError::NonZero { code, stderr } => {
+                WorktreeError::NonZero { code, stderr }
+            }
+        }
+    }
+}
+
 /// Runs `git worktree add` rooted at `base_repo`. By default worktrees land
 /// inside the repository itself at `<repo>/worktrees/<branch>` (#56) so they
 /// are findable from the repo; an operator-set root overrides that.
@@ -39,9 +48,9 @@ impl WorktreeManager {
     }
 
     /// Where a worktree for `branch` will be created: the override root, or
-    /// `<main checkout>/worktrees/<sanitized branch>` by default. The path is
-    /// predictable (no UUID suffix), so an existing directory at the target
-    /// is an error rather than a silently different location.
+    /// `<main checkout>/worktrees/<sanitized branch>` by default. If the path
+    /// is occupied, [`Self::add_new`] / [`Self::add_existing`] sidestep to
+    /// `<path>-2`, `<path>-3`, ... instead.
     ///
     /// `base_repo` is whatever the client picked, which the project list makes
     /// easy to point at a *linked worktree* — placing the new tree inside it
@@ -51,23 +60,36 @@ impl WorktreeManager {
     /// uncommitted work (#54 review). Always place against the main checkout.
     ///
     /// The override root gets the repo's basename too: without it two repos
-    /// spawning the same branch name target one directory and the second
-    /// fails with `PathExists`.
+    /// spawning the same branch name target one directory.
     fn target_path(&self, base_repo: &Path, branch: &str) -> PathBuf {
-        let slug = sanitize_branch_for_path(branch);
+        // An unusable branch name falls back to a digest rather than escaping
+        // the root; `run_add` surfaces git's own error for it anyway.
+        let slug = branch_relpath(branch).unwrap_or_else(|| PathBuf::from(short_hash(branch)));
         let main = main_checkout(base_repo);
         match &self.root_override {
             Some(root) => {
-                let repo = main
+                // Basename alone collides for two checkouts of the same name
+                // (`~/a/maestro` and `~/b/maestro`), so disambiguate with a
+                // digest of the full path (#54 review).
+                let base = main
                     .file_name()
                     .map(|n| n.to_string_lossy().into_owned())
                     .unwrap_or_else(|| "repo".into());
+                let repo = format!("{base}-{}", short_hash(&main.to_string_lossy()));
                 root.join(repo).join(slug)
             }
             None => main.join("worktrees").join(slug),
         }
     }
 
+    /// [`Self::target_path`] with `-n` appended to the final component, the
+    /// collision suffix (#77).
+    fn target_path_suffixed(&self, base_repo: &Path, branch: &str, n: u32) -> PathBuf {
+        let mut name = self.target_path(base_repo, branch).into_os_string();
+        name.push(format!("-{n}"));
+        PathBuf::from(name)
+    }
+
     /// `git -C <base_repo> worktree add -b <branch> <path>` — creates the
     /// branch. Returns the path of the new worktree on success.
     pub fn add_new(&self, base_repo: &Path, branch: &str) -> Result<PathBuf, WorktreeError> {
@@ -86,12 +108,18 @@ impl WorktreeManager {
         branch: &str,
         create_branch: bool,
     ) -> Result<PathBuf, WorktreeError> {
-        let path = self.target_path(base_repo, branch);
-        // Clear registrations whose directory is gone before testing the
-        // path, so a previously-leaked entry doesn't block this branch.
+        // Clear registrations whose directory is gone first, so a
+        // previously-leaked entry doesn't push this branch to a suffix.
         prune(base_repo)?;
-        if path.symlink_metadata().is_ok() {
-            return Err(WorktreeError::PathExists { path });
+        // Anything occupying the target — a tree we left behind, one the
+        // operator made, an unrelated directory — is sidestepped with a
+        // numeric suffix on the directory; the branch stays whatever was
+        // requested (#77). The daemon never adopts what it finds.
+        let mut path = self.target_path(base_repo, branch);
+        let mut n = 1;
+        while path.symlink_metadata().is_ok() {
+            n += 1;
+            path = self.target_path_suffixed(base_repo, branch, n);
         }
         // The parent (`<repo>/worktrees` or the override root) may not exist
         // yet; the target itself must not.
@@ -111,12 +139,13 @@ impl WorktreeManager {
         Ok(path)
     }
 
-    /// `git -C <base_repo> worktree remove <path>` — but only when the
-    /// worktree holds nothing unique (#56). A worktree with uncommitted
-    /// changes, or with commits reachable from no other ref, is refused and
-    /// left on disk so the operator can rescue it; cleanup is unconditional,
-    /// which makes this guard the only thing standing between a stray kill
-    /// and destroyed work.
+    /// `git -C <base_repo> worktree remove <path>`.
+    ///
+    /// Unconditional (#79): the guard moved off the worktree and onto the
+    /// kill, so by the time removal runs the caller has already chosen to
+    /// destroy the tree — the kill only gets here after
+    /// [`crate::worktree_probe::in_the_way`] came back clear. Still refused for a tree holding a
+    /// nested registered worktree, which `git status` cannot see.
     pub fn remove(&self, base_repo: &Path, path: &Path) -> Result<(), WorktreeError> {
         // Gone from disk already (operator `rm -rf`, or a create that failed
         // half-way). Probing it with git would fail and be misread as unsaved
@@ -132,12 +161,6 @@ impl WorktreeManager {
                 reason: format!("holds a nested worktree at {}", inner.display()),
             });
         }
-        if let Some(reason) = unsafe_to_remove(path)? {
-            return Err(WorktreeError::Guarded {
-                path: path.to_path_buf(),
-                reason,
-            });
-        }
         let out = Command::new("git")
             .arg("-C")
             .arg(base_repo)
@@ -180,44 +203,60 @@ fn nested_worktree(path: &Path) -> Option<PathBuf> {
         .args(["worktree", "list", "--porcelain"])
         .output()
         .ok()?;
+    // `worktree list` prints fully-resolved paths while ours comes from
+    // `--git-common-dir` and may still hold symlinks. Comparing the two forms
+    // directly makes the guard silently pass on any symlinked repo path — and
+    // this guard is what stands between a kill and deleting an inner
+    // worktree's uncommitted work (#54 review).
+    let needle = path.canonicalize().unwrap_or_else(|_| path.to_path_buf());
     let text = String::from_utf8_lossy(&out.stdout);
     text.lines()
         .filter_map(|l| l.strip_prefix("worktree "))
         .map(PathBuf::from)
-        .find(|p| p != path && p.starts_with(path))
+        .find(|p| {
+            let real = p.canonicalize().unwrap_or_else(|_| p.clone());
+            real != needle && real.starts_with(&needle)
+        })
 }
 
-fn sanitize_branch_for_path(branch: &str) -> String {
-    let mut out = String::with_capacity(branch.len());
-    for c in branch.chars() {
-        if c.is_ascii_alphanumeric() || c == '-' || c == '_' {
-            out.push(c);
-        } else if c == '/' || c == '.' {
-            out.push('-');
-        }
-    }
-    if out.is_empty() {
-        out.push_str("wt");
-    }
-    out
-}
-
-/// `Some(reason)` when deleting `path` would destroy work.
+/// Short digest used to disambiguate override roots.
 ///
-/// Only an unclean working tree qualifies. `git worktree remove` deletes the
-/// checkout but keeps `refs/heads/<branch>`, so committed work — pushed or
-/// not — stays reachable and is never at risk. Guarding on "commits on no
-/// other ref" instead would refuse every ordinary unpushed feature branch,
-/// and because the path is deterministic that branch could then never be
-/// spawned again (#56 review).
-fn unsafe_to_remove(path: &Path) -> Result<Option<String>, WorktreeError> {
-    // `--ignored=no` keeps build output out of it; untracked sources count,
-    // since removal would delete them.
-    let status = run_git(path, ["status", "--porcelain", "--ignored=no"])?;
-    if !status.stdout.is_empty() {
-        return Ok(Some("has uncommitted changes".into()));
+/// Hand-rolled FNV-1a rather than `DefaultHasher`: this value becomes a
+/// directory name, and `DefaultHasher`'s algorithm is explicitly not
+/// guaranteed stable across Rust releases — a toolchain bump would remap every
+/// repo to a new directory and orphan the worktrees under the old one
+/// (#67 review).
+fn short_hash(s: &str) -> String {
+    let mut h: u32 = 0x811c_9dc5;
+    for b in s.as_bytes() {
+        h ^= u32::from(*b);
+        h = h.wrapping_mul(0x0100_0193);
     }
-    Ok(None)
+    format!("{h:08x}")
+}
+
+/// The relative directory a branch's worktree lives in.
+///
+/// A git branch name is already a valid relative path — git stores it as
+/// `.git/refs/heads/feat/example` — so it is used verbatim and `feat/example`
+/// nests under `worktrees/feat/`. That keeps the path readable *and* keeps the
+/// mapping injective: flattening `/` and `.` to `-` made `feat/x`, `feat.x`
+/// and `feat-x` share one directory (#54 review).
+///
+/// Git already forbids holding both `feat` and `feat/x`, so the directory
+/// collision that nesting could cause cannot arise from valid refs. Only
+/// traversal and absolute components are rejected.
+fn branch_relpath(branch: &str) -> Option<PathBuf> {
+    use std::path::Component;
+    let candidate = Path::new(branch);
+    if branch.is_empty()
+        || !candidate
+            .components()
+            .all(|c| matches!(c, Component::Normal(_)))
+    {
+        return None;
+    }
+    Some(candidate.to_path_buf())
 }
 
 /// `git -C <base_repo> worktree prune` — drops registrations whose directory
@@ -231,22 +270,6 @@ fn prune(base_repo: &Path) -> Result<(), WorktreeError> {
     check(out)
 }
 
-fn run_git(
-    dir: &Path,
-    args: impl IntoIterator<Item = &'static str>,
-) -> Result<Output, WorktreeError> {
-    let mut cmd = Command::new("git");
-    cmd.arg("-C").arg(dir).args(args);
-    let out = cmd.output()?;
-    if !out.status.success() {
-        return Err(WorktreeError::NonZero {
-            code: out.status.code().unwrap_or(-1),
-            stderr: String::from_utf8_lossy(&out.stderr).into_owned(),
-        });
-    }
-    Ok(out)
-}
-
 fn check(out: Output) -> Result<(), WorktreeError> {
     if out.status.success() {
         Ok(())

crates/maestro-daemon/src/worktree_probe.rs

@@ -0,0 +1,325 @@
+//! The one git probe for what a worktree holds that would be lost, plus
+//! guard-free reclaim (#79, #80).
+//!
+//! [`in_the_way`] is the single predicate behind all three paths: the kill
+//! refusal (#79), the natural-exit classifier (#82), and the retained list
+//! (#80). It lives here rather than in `worktree.rs` so that none of them can
+//! answer the question differently — #79 and #80 were built in parallel and
+//! each grew its own copy, which is exactly the drift this collapses.
+//!
+//! Reclaim never consults it: reclaim is the deliberate destructive act, and
+//! the operator chose it while looking at what was in the way.
+
+use std::path::Path;
+
+use maestro_protocol::InTheWay;
+
+#[derive(Debug, thiserror::Error)]
+pub enum ProbeError {
+    #[error("failed to spawn git: {0}")]
+    Spawn(#[from] std::io::Error),
+    #[error("git exited with code {code}: {stderr}")]
+    NonZero { code: i32, stderr: String },
+}
+
+/// What a kill refusal would report about the worktree at `path`, right now.
+///
+/// Ignored files never count (`--ignored=no`) — every Rust worktree has a
+/// `target/`, and counting those would put every tree permanently in the way.
+/// A directory that no longer exists reports nothing in the way: there is
+/// nothing left to lose, and the store's own pruning drops the entry.
+pub fn in_the_way(path: &Path) -> Result<InTheWay, ProbeError> {
+    let mut breakdown = InTheWay::default();
+    // `symlink_metadata` rather than `exists`: a broken symlink is gone for
+    // our purposes, and following it would probe the wrong tree.
+    if std::fs::symlink_metadata(path).is_err() {
+        return Ok(breakdown);
+    }
+    let status = run_git(
+        path,
+        [
+            "status",
+            "--porcelain",
+            "--ignored=no",
+            "--untracked-files=normal",
+        ],
+    )?;
+    for line in String::from_utf8_lossy(&status.stdout).lines() {
+        if line.starts_with("??") {
+            breakdown.untracked_files += 1;
+        } else if !line.is_empty() {
+            breakdown.uncommitted_files += 1;
+        }
+    }
+    // Resolved inside the worktree so a detached HEAD still has a starting
+    // point; asking the base repo for `refs/heads/<branch>` fails there.
+    let head = run_git(path, ["rev-parse", "--abbrev-ref", "HEAD"])?;
+    let branch = String::from_utf8_lossy(&head.stdout).trim().to_string();
+    let tip: &str = if branch == "HEAD" { "HEAD" } else { &branch };
+    // Commits reachable from the tip but from no remote-tracking ref. A branch
+    // pushed anywhere counts as pushed; there is no "which remote" question to
+    // get wrong.
+    let unpushed = run_git(path, ["rev-list", "--count", tip, "--not", "--remotes"])?;
+    breakdown.unpushed_commits = String::from_utf8_lossy(&unpushed.stdout)
+        .trim()
+        .parse()
+        .unwrap_or(0);
+    Ok(breakdown)
+}
+
+/// Remove a retained worktree's directory without consulting any guard, per
+/// the reclaim contract: the operator chose this while looking at what was in
+/// the way. `git worktree remove` keeps `refs/heads/<branch>`, so commits on
+/// the branch survive even when they were never pushed.
+///
+/// A directory that is already gone only leaves a stale registration behind;
+/// `worktree prune` clears it so the branch can be spawned again.
+pub fn reclaim(base_repo: &Path, path: &Path) -> Result<(), ProbeError> {
+    if !path.exists() {
+        return run_git(base_repo, ["worktree", "prune"]).map(|_| ());
+    }
+    run_git(
+        base_repo,
+        [
+            "worktree",
+            "remove",
+            "--force",
+            path.to_str().expect("worktree path is valid utf-8"),
+        ],
+    )
+    .map(|_| ())
+}
+
+/// Branch checked out at `path`. Sessions adopted from a sidecar carry no
+/// branch on record, so a forced kill (#81) asks the tree itself when it
+/// needs one for the retained store. `None` when git cannot answer.
+pub fn current_branch(path: &Path) -> Option<String> {
+    let out = run_git(path, ["rev-parse", "--abbrev-ref", "HEAD"]).ok()?;
+    Some(String::from_utf8_lossy(&out.stdout).trim().to_string())
+}
+
+fn run_git<I, S>(dir: &Path, args: I) -> Result<std::process::Output, ProbeError>
+where
+    I: IntoIterator<Item = S>,
+    S: AsRef<std::ffi::OsStr>,
+{
+    let mut cmd = std::process::Command::new("git");
+    cmd.arg("-C").arg(dir).args(args);
+    let out = cmd.output()?;
+    if !out.status.success() {
+        return Err(ProbeError::NonZero {
+            code: out.status.code().unwrap_or(-1),
+            stderr: String::from_utf8_lossy(&out.stderr).into_owned(),
+        });
+    }
+    Ok(out)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::path::PathBuf;
+    use std::process::Command;
+
+    struct Repo {
+        root: tempfile::TempDir,
+        repo: PathBuf,
+    }
+
+    fn git(dir: &Path, args: &[&str]) {
+        let out = Command::new("git")
+            .arg("-C")
+            .arg(dir)
+            .args(args)
+            .output()
+            .expect("git spawn");
+        assert!(
+            out.status.success(),
+            "git {args:?} failed: {}",
+            String::from_utf8_lossy(&out.stderr)
+        );
+    }
+
+    /// A repo with a remote, one commit on `main`, and a linked worktree for
+    /// branch `feature` at `<repo>/worktrees/feature`.
+    fn repo_with_worktree() -> Repo {
+        let root = tempfile::tempdir().expect("tempdir");
+        let repo = root.path().join("repo");
+        let remote = root.path().join("remote.git");
+        std::fs::create_dir_all(&repo).unwrap();
+        std::fs::create_dir_all(&remote).unwrap();
+        git(&repo, &["init", "-q", "-b", "main"]);
+        git(&repo, &["config", "user.email", "t@t"]);
+        git(&repo, &["config", "user.name", "T"]);
+        std::fs::write(repo.join("README"), b"hello\n").unwrap();
+        git(&repo, &["add", "."]);
+        git(&repo, &["commit", "-q", "-m", "init"]);
+        git(&remote, &["init", "-q", "--bare"]);
+        git(&repo, &["remote", "add", "origin", &path_str(&remote)]);
+        git(&repo, &["push", "-q", "-u", "origin", "main"]);
+        git(
+            &repo,
+            &[
+                "worktree",
+                "add",
+                "-q",
+                "-b",
+                "feature",
+                "worktrees/feature",
+            ],
+        );
+        Repo { root, repo }
+    }
+
+    fn path_str(path: &Path) -> String {
+        path.to_string_lossy().into_owned()
+    }
+
+    impl Repo {
+        fn wt(&self) -> PathBuf {
+            self.repo.join("worktrees").join("feature")
+        }
+
+        fn commit_in_wt(&self, msg: &str) {
+            std::fs::write(self.wt().join("README"), msg.as_bytes()).unwrap();
+            git(&self.wt(), &["add", "-A"]);
+            git(&self.wt(), &["commit", "-qm", msg]);
+        }
+    }
+
+    #[test]
+    fn a_clean_pushed_worktree_has_nothing_in_the_way() {
+        let r = repo_with_worktree();
+        git(&r.wt(), &["push", "-q", "-u", "origin", "feature"]);
+        let breakdown = in_the_way(&r.wt()).expect("probe");
+        assert_eq!(breakdown, InTheWay::default());
+        assert!(breakdown.is_clear());
+    }
+
+    #[test]
+    fn uncommitted_untracked_and_unpushed_are_counted_separately() {
+        let r = repo_with_worktree();
+        std::fs::write(r.wt().join("README"), b"edited\n").unwrap();
+        std::fs::write(r.wt().join("scratch.txt"), b"untracked\n").unwrap();
+
+        let dirty = in_the_way(&r.wt()).expect("probe");
+        assert_eq!(dirty.uncommitted_files, 1);
+        assert_eq!(dirty.untracked_files, 1);
+        assert_eq!(dirty.unpushed_commits, 0);
+        assert!(!dirty.is_clear());
+
+        // Committing clears exactly one dimension and creates another.
+        git(&r.wt(), &["add", "README"]);
+        git(&r.wt(), &["commit", "-qm", "wip"]);
+
+        let breakdown = in_the_way(&r.wt()).expect("probe");
+        assert_eq!(breakdown.uncommitted_files, 0);
+        assert_eq!(breakdown.untracked_files, 1);
+        assert_eq!(breakdown.unpushed_commits, 1);
+    }
+
+    #[test]
+    fn tracked_edits_count_as_uncommitted() {
+        let r = repo_with_worktree();
+        std::fs::write(r.wt().join("README"), b"edited\n").unwrap();
+        let breakdown = in_the_way(&r.wt()).expect("probe");
+        assert_eq!(breakdown.uncommitted_files, 1);
+        assert_eq!(breakdown.untracked_files, 0);
+    }
+
+    #[test]
+    fn pushing_clears_unpushed_but_keeps_other_entries() {
+        let r = repo_with_worktree();
+        std::fs::write(r.wt().join("new.txt"), b"x\n").unwrap();
+        r.commit_in_wt("wip");
+
+        let before = in_the_way(&r.wt()).expect("probe");
+        assert_eq!(before.unpushed_commits, 1);
+
+        git(&r.wt(), &["push", "-q", "-u", "origin", "feature"]);
+        // Same stored entry, different tree: the breakdown must move with it.
+        let after = in_the_way(&r.wt()).expect("probe");
+        assert_eq!(after.unpushed_commits, 0);
+        assert_eq!(after.untracked_files, 0);
+
+        std::fs::write(r.wt().join("loose.txt"), b"x\n").unwrap();
+        let dirty = in_the_way(&r.wt()).expect("probe");
+        assert_eq!(dirty.untracked_files, 1);
+    }
+
+    #[test]
+    fn ignored_files_never_count() {
+        let r = repo_with_worktree();
+        std::fs::write(r.wt().join(".gitignore"), b"target/\n").unwrap();
+        std::fs::create_dir_all(r.wt().join("target")).unwrap();
+        std::fs::write(r.wt().join("target/artifact"), b"x").unwrap();
+
+        let breakdown = in_the_way(&r.wt()).expect("probe");
+        assert_eq!(
+            breakdown,
+            InTheWay {
+                untracked_files: 1,
+                ..InTheWay::default()
+            },
+            "the .gitignore itself is untracked; target/ is not"
+        );
+    }
+
+    #[test]
+    fn a_missing_directory_reports_nothing_in_the_way() {
+        let r = repo_with_worktree();
+        let gone = r.root.path().join("nowhere");
+        let breakdown = in_the_way(&gone).expect("probe");
+        assert!(breakdown.is_clear());
+    }
+
+    #[test]
+    fn reclaim_removes_the_directory_and_prunes_a_gone_one() {
+        let r = repo_with_worktree();
+        r.commit_in_wt("precious");
+        reclaim(&r.repo, &r.wt()).expect("reclaim");
+        assert!(!r.wt().exists());
+
+        // A second reclaim over the now-missing path just prunes.
+        reclaim(&r.repo, &r.wt()).expect("reclaim again");
+    }
+
+    #[test]
+    fn reclaim_keeps_the_branch_and_its_commits() {
+        let r = repo_with_worktree();
+        r.commit_in_wt("precious");
+        let sha = {
+            let out = Command::new("git")
+                .arg("-C")
+                .arg(r.wt())
+                .args(["rev-parse", "HEAD"])
+                .output()
+                .unwrap();
+            String::from_utf8_lossy(&out.stdout).trim().to_string()
+        };
+
+        reclaim(&r.repo, &r.wt()).expect("reclaim");
+
+        let out = Command::new("git")
+            .arg("-C")
+            .arg(&r.repo)
+            .args(["rev-parse", "--verify", "refs/heads/feature"])
+            .output()
+            .unwrap();
+        assert!(
+            out.status.success(),
+            "branch must survive reclaim: {}",
+            String::from_utf8_lossy(&out.stderr)
+        );
+        assert_eq!(String::from_utf8_lossy(&out.stdout).trim(), sha);
+    }
+
+    #[test]
+    fn reclaim_is_guard_free_on_a_dirty_tree() {
+        let r = repo_with_worktree();
+        std::fs::write(r.wt().join("README"), b"unsaved\n").unwrap();
+        std::fs::write(r.wt().join("notes.txt"), b"unsaved\n").unwrap();
+        reclaim(&r.repo, &r.wt()).expect("reclaim ignores the guard");
+        assert!(!r.wt().exists());
+    }
+}

crates/maestro-daemon/tests/attach.rs

@@ -38,6 +38,7 @@ async fn spawn_daemon_ws() -> Harness {
         "/home/test",
         Vec::new(),
         std::sync::Arc::new(maestro_daemon::projects::ProjectScanner::disabled()),
+        std::sync::Arc::new(fx.retained_store()),
     ));
     let listener = TcpListener::bind(SocketAddr::from((Ipv4Addr::LOCALHOST, 0)))
         .await
@@ -121,7 +122,7 @@ async fn pty_round_trip_through_real_tmux() {
         "marker not seen in {} bytes",
         got.len()
     );
-    let _ = h.manager.kill(id).await;
+    let _ = h.manager.kill(id, false).await;
 }
 
 #[tokio::test]
@@ -169,7 +170,7 @@ async fn multi_attach_broadcasts_to_every_client() {
         "client B missed marker"
     );
 
-    let _ = h.manager.kill(id).await;
+    let _ = h.manager.kill(id, false).await;
 }
 
 #[tokio::test]
@@ -218,7 +219,7 @@ async fn sends_close_frame_when_session_is_killed() {
     // give the broadcast subscriber a moment to register before killing.
     tokio::time::sleep(Duration::from_millis(100)).await;
 
-    h.manager.kill(id).await.unwrap();
+    h.manager.kill(id, false).await.unwrap();
 
     let mut saw_close = false;
     let deadline = std::time::Instant::now() + Duration::from_secs(2);
@@ -266,7 +267,7 @@ async fn ping_text_frame_gets_pong() {
         }
     }
     assert!(saw_pong, "no Pong frame received");
-    let _ = h.manager.kill(id).await;
+    let _ = h.manager.kill(id, false).await;
 }
 
 #[tokio::test]

crates/maestro-daemon/tests/blocked_work_cost.rs

@@ -0,0 +1,116 @@
+//! The performance contract of #83: the blocked-work pass must cost NO git
+//! probe at all for a session without a worktree, while a session with one is
+//! still probed.
+//!
+//! `git` itself is shimmed through PATH with a wrapper that logs every
+//! invocation before exec'ing the real binary, so the assertion counts actual
+//! probes rather than inferring them from state. This lives in its own test
+//! binary because it mutates the process environment.
+
+mod common;
+
+use std::collections::HashMap;
+use std::process::Command;
+use std::time::Duration;
+
+use common::{init_bare_repo, init_repo, push_all_to_origin, wait_for_async, DaemonFixture};
+use maestro_protocol::{CreateSessionRequest, InTheWay, WorktreeSpec};
+use tempfile::TempDir;
+
+fn request(cwd: &std::path::Path, repo: &std::path::Path, branch: &str) -> CreateSessionRequest {
+    CreateSessionRequest {
+        cwd: cwd.to_path_buf(),
+        command: "sleep 30".into(),
+        env: HashMap::new(),
+        metadata: HashMap::new(),
+        worktree: Some(WorktreeSpec {
+            base_repo: repo.to_path_buf(),
+            branch: branch.into(),
+            create_branch: true,
+        }),
+    }
+}
+
+#[tokio::test]
+async fn a_session_without_a_worktree_costs_no_probe() {
+    let fx = DaemonFixture::new();
+    let log = TempDir::new().unwrap();
+    let log_path = log.path().join("git-calls.log");
+
+    // Session A owns a real (pristine, pushed) worktree; session B has none.
+    let repo_a = TempDir::new().unwrap();
+    init_repo(repo_a.path());
+    init_bare_repo(&repo_a.path().join("origin.git"));
+    push_all_to_origin(repo_a.path(), &repo_a.path().join("origin.git"));
+    fx.manager
+        .create(request(repo_a.path(), repo_a.path(), "feat/probed"))
+        .await
+        .expect("create A");
+
+    let cwd_b = TempDir::new().unwrap();
+    let mut req_b = request(cwd_b.path(), cwd_b.path(), "feat/unused");
+    req_b.worktree = None;
+    fx.manager.create(req_b).await.expect("create B");
+
+    // Shim `git` AFTER setup so only watcher-driven probes get logged.
+    let real_git = String::from_utf8(
+        Command::new("sh")
+            .arg("-c")
+            .arg("command -v git")
+            .output()
+            .expect("locate git")
+            .stdout,
+    )
+    .unwrap()
+    .trim()
+    .to_string();
+    let shim_dir = TempDir::new().unwrap();
+    let script = format!(
+        "#!/bin/sh\nprintf '%s\\n' \"$*\" >> {}\nexec {} \"$@\"\n",
+        log_path.display(),
+        real_git,
+    );
+    std::fs::write(shim_dir.path().join("git"), script).unwrap();
+    #[cfg(unix)]
+    {
+        use std::os::unix::fs::PermissionsExt;
+        std::fs::set_permissions(
+            shim_dir.path().join("git"),
+            std::fs::Permissions::from_mode(0o755),
+        )
+        .unwrap();
+    }
+    let old_path = std::env::var("PATH").unwrap_or_default();
+    std::env::set_var(
+        "PATH",
+        format!("{}:{}", shim_dir.path().display(), old_path),
+    );
+
+    fx.manager.start_liveness_watcher_with_blocked_work(
+        Duration::from_millis(50),
+        Duration::from_millis(100),
+    );
+
+    // The pass demonstrably runs and probed A's tree...
+    wait_for_async(Duration::from_secs(5), || async {
+        fx.manager
+            .snapshot()
+            .await
+            .iter()
+            .any(|s| s.worktree.is_some() && s.blocked_work == Some(InTheWay::default()))
+    })
+    .await;
+
+    std::env::set_var("PATH", &old_path);
+
+    let calls = std::fs::read_to_string(&log_path).unwrap_or_default();
+    assert!(
+        !calls.is_empty(),
+        "the pass never probed anything — the shim saw no git call at all"
+    );
+    // ...while B — no worktree, so nothing to probe — was never touched.
+    assert!(
+        !calls.contains(cwd_b.path().to_str().unwrap()),
+        "a worktree-less session was probed:\n{calls}"
+    );
+}

crates/maestro-daemon/tests/branches.rs

@@ -27,6 +27,7 @@ async fn spawn() -> Harness {
         "/home/test",
         presets,
         Arc::new(maestro_daemon::projects::ProjectScanner::disabled()),
+        std::sync::Arc::new(fx.retained_store()),
     ));
     let listener = TcpListener::bind(SocketAddr::from((Ipv4Addr::LOCALHOST, 0)))
         .await

crates/maestro-daemon/tests/common/mod.rs

@@ -93,6 +93,38 @@ fn run(cmd: &mut Command) {
     );
 }
 
+/// An empty bare repository at `dir`, usable as a push target (#79).
+pub fn init_bare_repo(dir: &Path) {
+    run(Command::new("git")
+        .arg("init")
+        .arg("-q")
+        .arg("--bare")
+        .arg(dir.to_str().expect("non-utf8 bare repo path")));
+}
+
+/// Push every branch of `repo` to `origin`, creating remote-tracking refs.
+///
+/// The unsaved-work probe (#79) counts commits reachable from no
+/// remote-tracking ref as unpushed, so tests that want a killable worktree
+/// must give its branch one. Safe to call again: re-adding an existing
+/// remote is ignored.
+pub fn push_all_to_origin(repo: &Path, origin: &Path) {
+    let _ = Command::new("git")
+        .arg("-C")
+        .arg(repo)
+        .args([
+            "remote",
+            "add",
+            "origin",
+            origin.to_str().expect("non-utf8 origin path"),
+        ])
+        .status();
+    run(Command::new("git")
+        .arg("-C")
+        .arg(repo)
+        .args(["push", "-q", "--all", "origin"]));
+}
+
 /// Async polling sibling of [`wait_for`] for tokio tests.
 pub async fn wait_for_async<F, Fut>(timeout: Duration, mut cond: F)
 where
@@ -144,6 +176,11 @@ impl DaemonFixture {
             manager =
                 manager.with_spawn_history(SpawnHistory::new(Self::history_path(&state_dir), days));
         }
+        // Same wiring as production: the manager records retained worktrees
+        // into the same dir the API reads back from (#78/#81).
+        let retained =
+            maestro_daemon::retained_store::RetainedStore::new(Self::retained_path(&state_dir));
+        manager = manager.with_retained_store(retained.clone());
         Self {
             tmux,
             manager,
@@ -155,6 +192,10 @@ impl DaemonFixture {
         state_dir.path().join("spawn-history.jsonl")
     }
 
+    fn retained_path(state_dir: &TempDir) -> PathBuf {
+        state_dir.path().join("retained-worktrees")
+    }
+
     pub fn spawn_history_path(&self) -> PathBuf {
         Self::history_path(&self.state_dir)
     }
@@ -163,6 +204,15 @@ impl DaemonFixture {
         self.state_dir.path().join("sessions")
     }
 
+    /// Retained-worktree store rooted at the fixture's own state dir (#78).
+    pub fn retained_store(&self) -> maestro_daemon::retained_store::RetainedStore {
+        maestro_daemon::retained_store::RetainedStore::new(self.retained_dir())
+    }
+
+    pub fn retained_dir(&self) -> PathBuf {
+        self.state_dir.path().join("retained-worktrees")
+    }
+
     pub fn fifo_dir(&self) -> PathBuf {
         self.state_dir.path().join("fifos")
     }

crates/maestro-daemon/tests/local_api.rs

@@ -9,7 +9,7 @@ use std::time::Duration;
 use common::DaemonFixture;
 use futures_util::{SinkExt, StreamExt};
 use maestro_daemon::local_api;
-use maestro_protocol::{CreateSessionRequest, Session};
+use maestro_protocol::{ApiError, CreateSessionRequest, Session, WorktreeSpec};
 use tokio::net::TcpListener;
 use tokio::sync::oneshot;
 use tokio_tungstenite::tungstenite::Message as WsMessage;
@@ -25,6 +25,13 @@ struct Harness {
     _fx: DaemonFixture,
 }
 
+impl Harness {
+    /// Store over the same dir the manager records into.
+    fn fx_retained(&self) -> maestro_daemon::retained_store::RetainedStore {
+        self._fx.retained_store()
+    }
+}
+
 async fn spawn(hostname: &str) -> Harness {
     spawn_with(
         hostname,
@@ -48,6 +55,7 @@ async fn spawn_with(
         "/home/test",
         presets,
         projects,
+        std::sync::Arc::new(fx.retained_store()),
     ));
     let listener = TcpListener::bind(SocketAddr::from((Ipv4Addr::LOCALHOST, 0)))
         .await
@@ -338,6 +346,107 @@ async fn delete_owned_session_kills_it() {
     assert!(!h.manager.has(session.id).await);
 }
 
+/// The kill guard on the wire (#79): `DELETE /api/sessions/:id` answers 409
+/// with the structured breakdown, and the session keeps running.
+#[tokio::test]
+async fn delete_a_session_whose_worktree_holds_unsaved_work_returns_409_with_the_breakdown() {
+    let h = spawn("naps-laptop").await;
+    let repo = tempfile::TempDir::new().unwrap();
+    common::init_repo(repo.path());
+    let session = h
+        .manager
+        .create(CreateSessionRequest {
+            cwd: repo.path().to_path_buf(),
+            command: "sleep 60".into(),
+            env: HashMap::new(),
+            metadata: HashMap::new(),
+            worktree: Some(WorktreeSpec {
+                base_repo: repo.path().to_path_buf(),
+                branch: "feat/guarded".into(),
+                create_branch: true,
+            }),
+        })
+        .await
+        .unwrap();
+    std::fs::write(
+        repo.path()
+            .join("worktrees")
+            .join("feat")
+            .join("guarded")
+            .join("README"),
+        b"unsaved edits\n",
+    )
+    .unwrap();
+
+    let resp = reqwest::Client::new()
+        .delete(url(h.addr, &format!("/api/sessions/{}", session.id)))
+        .send()
+        .await
+        .unwrap();
+    assert_eq!(resp.status(), reqwest::StatusCode::CONFLICT);
+    let body: ApiError = resp.json().await.unwrap();
+    assert_eq!(body.error.code, "kill_guarded");
+    let breakdown = body.error.unsaved_work.expect("breakdown on the wire");
+    assert_eq!(breakdown.uncommitted_files, 1);
+
+    assert!(h.manager.has(session.id).await, "the session keeps running");
+}
+
+/// `?force=true` on the wire (#81): the refusal is overridden, the session
+/// ends, and the answer is 200 with the retained worktree named — path,
+/// branch, reason — while the directory survives on disk.
+#[tokio::test]
+async fn delete_with_force_ends_the_session_and_answers_what_was_retained() {
+    let h = spawn("naps-laptop").await;
+    let repo = tempfile::TempDir::new().unwrap();
+    common::init_repo(repo.path());
+    let wt_path = repo
+        .path()
+        .join("worktrees")
+        .join("feat")
+        .join("guarded")
+        .to_path_buf();
+    let session = h
+        .manager
+        .create(CreateSessionRequest {
+            cwd: repo.path().to_path_buf(),
+            command: "sleep 60".into(),
+            env: HashMap::new(),
+            metadata: HashMap::new(),
+            worktree: Some(WorktreeSpec {
+                base_repo: repo.path().to_path_buf(),
+                branch: "feat/guarded".into(),
+                create_branch: true,
+            }),
+        })
+        .await
+        .unwrap();
+    std::fs::write(wt_path.join("README"), b"unsaved edits\n").unwrap();
+
+    let resp = reqwest::Client::new()
+        .delete(url(h.addr, &format!("/api/sessions/{}", session.id)))
+        .query(&[("force", "true")])
+        .send()
+        .await
+        .unwrap();
+    assert_eq!(resp.status(), reqwest::StatusCode::OK);
+    let body: maestro_protocol::KillOutcome = resp.json().await.unwrap();
+    let retained = body.retained.expect("force names what was kept");
+    assert_eq!(retained.path, wt_path);
+    assert_eq!(retained.branch, "feat/guarded");
+    assert_eq!(
+        retained.reason,
+        maestro_protocol::RetainedReason::ForceKilled
+    );
+
+    // The tree would have blocked; force must not have removed it.
+    assert!(wt_path.exists(), "a forced kill never removes the worktree");
+    // And the store entry exists, so reclaim can find it (#80).
+    let all = h.fx_retained().load_all().unwrap();
+    assert_eq!(all.len(), 1);
+    assert_eq!(all[0].id, retained.id);
+}
+
 #[tokio::test]
 async fn attach_ws_streams_pty_bytes() {
     let h = spawn("naps-laptop").await;
@@ -428,7 +537,7 @@ async fn events_ws_sends_a_snapshot_then_streams_deltas() {
         other => panic!("expected SessionAdded, got {other:?}"),
     }
 
-    h.manager.kill(created.id).await.expect("kill");
+    h.manager.kill(created.id, false).await.expect("kill");
 
     // Activity ticks may interleave; the removal is what we are waiting for.
     let deadline = tokio::time::Instant::now() + Duration::from_secs(5);
@@ -492,3 +601,234 @@ async fn next_event(ws: &mut WsClient) -> maestro_protocol::CatalogEvent {
         }
     }
 }
+
+// ---------------------------------------------------------------------------
+// GET /api/worktrees + DELETE /api/worktrees/:id (#80)
+// ---------------------------------------------------------------------------
+
+/// `git -C dir args`, asserting success — the worktree endpoints are tested
+/// against real git, like everything else in this crate.
+fn git(dir: &std::path::Path, args: &[&str]) {
+    let out = std::process::Command::new("git")
+        .arg("-C")
+        .arg(dir)
+        .args(args)
+        .output()
+        .expect("git spawn");
+    assert!(
+        out.status.success(),
+        "git {args:?} failed: {}",
+        String::from_utf8_lossy(&out.stderr)
+    );
+}
+
+struct RetainedFixture {
+    repo: tempfile::TempDir,
+    wt: std::path::PathBuf,
+}
+
+/// A real repo with a linked worktree for branch `feat/login` whose tree holds
+/// an uncommitted tracked edit and an unpushed commit.
+fn retained_fixture() -> RetainedFixture {
+    let repo = tempfile::tempdir().unwrap();
+    common::init_repo(repo.path());
+    // A pushed main, so "unpushed" means commits made on the feature branch,
+    // not the shared history.
+    let remote = repo.path().join("remote.git");
+    std::fs::create_dir_all(&remote).unwrap();
+    let remote_s = remote.to_string_lossy().into_owned();
+    git(&remote, &["init", "-q", "--bare"]);
+    git(repo.path(), &["remote", "add", "origin", &remote_s]);
+    git(repo.path(), &["push", "-q", "-u", "origin", "main"]);
+    git(
+        repo.path(),
+        &[
+            "worktree",
+            "add",
+            "-q",
+            "-b",
+            "feat/login",
+            "worktrees/feat/login",
+        ],
+    );
+    let wt = repo.path().join("worktrees").join("feat").join("login");
+    RetainedFixture { repo, wt }
+}
+
+impl RetainedFixture {
+    fn commit_in_wt(&self, msg: &str) {
+        std::fs::write(self.wt.join("README"), msg.as_bytes()).unwrap();
+        git(&self.wt, &["add", "-A"]);
+        git(&self.wt, &["commit", "-qm", msg]);
+    }
+
+    fn branch_sha(&self, branch: &str) -> String {
+        let out = std::process::Command::new("git")
+            .arg("-C")
+            .arg(self.repo.path())
+            .args(["rev-parse", "--verify", &format!("refs/heads/{branch}")])
+            .output()
+            .unwrap();
+        assert!(out.status.success(), "branch {branch} must exist");
+        String::from_utf8_lossy(&out.stdout).trim().to_string()
+    }
+}
+
+#[tokio::test]
+async fn worktrees_lists_retained_entries_with_recomputed_breakdown() {
+    let h = spawn("naps-laptop").await;
+    let fx = retained_fixture();
+    // Uncommitted tracked edit + an untracked file; the branch has no commits
+    // beyond main yet.
+    std::fs::write(fx.wt.join("README"), b"unsaved\n").unwrap();
+    std::fs::write(fx.wt.join("scratch.txt"), b"loose\n").unwrap();
+
+    let store = h._fx.retained_store();
+    let entry = store
+        .retain(
+            &fx.wt,
+            fx.repo.path(),
+            "feat/login",
+            maestro_daemon::retained_store::RetainedReason::ForceKilled,
+        )
+        .unwrap();
+
+    let listed: Vec<maestro_protocol::RetainedWorktree> =
+        reqwest::get(url(h.addr, "/api/worktrees"))
+            .await
+            .unwrap()
+            .json()
+            .await
+            .unwrap();
+    assert_eq!(listed.len(), 1);
+    let w = &listed[0];
+    assert_eq!(w.id, entry.id);
+    assert_eq!(w.path, fx.wt);
+    assert_eq!(w.base_repo, fx.repo.path());
+    assert_eq!(w.branch, "feat/login");
+    assert_eq!(w.reason, maestro_protocol::RetainedReason::ForceKilled);
+    assert_eq!(w.in_the_way.uncommitted_files, 1);
+    assert_eq!(w.in_the_way.untracked_files, 1);
+    assert_eq!(w.in_the_way.unpushed_commits, 0);
+
+    // The operator saves the work themselves. The stored entry is untouched —
+    // the next read must report the tree as it is *now*, not as it was when
+    // it was retained.
+    fx.commit_in_wt("saved");
+    let listed: Vec<maestro_protocol::RetainedWorktree> =
+        reqwest::get(url(h.addr, "/api/worktrees"))
+            .await
+            .unwrap()
+            .json()
+            .await
+            .unwrap();
+    assert_eq!(listed.len(), 1, "same entry, still retained");
+    assert_eq!(listed[0].id, entry.id);
+    assert_eq!(listed[0].in_the_way.uncommitted_files, 0);
+    assert_eq!(listed[0].in_the_way.unpushed_commits, 1);
+}
+
+#[tokio::test]
+async fn reclaim_removes_directory_and_entry_but_never_the_branch() {
+    let h = spawn("naps-laptop").await;
+    let fx = retained_fixture();
+    fx.commit_in_wt("precious");
+    let sha = fx.branch_sha("feat/login");
+    std::fs::write(fx.wt.join("README"), b"unsaved\n").unwrap(); // guard would refuse
+
+    let store = h._fx.retained_store();
+    let entry = store
+        .retain(
+            &fx.wt,
+            fx.repo.path(),
+            "feat/login",
+            maestro_daemon::retained_store::RetainedReason::ExitedWithUnsavedWork,
+        )
+        .unwrap();
+
+    let resp = reqwest::Client::new()
+        .delete(url(h.addr, &format!("/api/worktrees/{}", entry.id)))
+        .send()
+        .await
+        .unwrap();
+    assert_eq!(resp.status(), reqwest::StatusCode::NO_CONTENT);
+
+    assert!(!fx.wt.exists(), "reclaim removes the directory");
+    let listed: Vec<maestro_protocol::RetainedWorktree> =
+        reqwest::get(url(h.addr, "/api/worktrees"))
+            .await
+            .unwrap()
+            .json()
+            .await
+            .unwrap();
+    assert!(listed.is_empty(), "reclaim drops the store entry");
+    assert_eq!(
+        fx.branch_sha("feat/login"),
+        sha,
+        "the branch and its commits survive"
+    );
+}
+
+#[tokio::test]
+async fn reclaim_of_an_already_gone_directory_still_drops_the_entry() {
+    let h = spawn("naps-laptop").await;
+    let fx = retained_fixture();
+    let store = h._fx.retained_store();
+    let entry = store
+        .retain(
+            &fx.wt,
+            fx.repo.path(),
+            "feat/login",
+            maestro_daemon::retained_store::RetainedReason::ForceKilled,
+        )
+        .unwrap();
+    std::fs::remove_dir_all(&fx.wt).unwrap(); // operator rm -rf
+
+    let resp = reqwest::Client::new()
+        .delete(url(h.addr, &format!("/api/worktrees/{}", entry.id)))
+        .send()
+        .await
+        .unwrap();
+    assert_eq!(resp.status(), reqwest::StatusCode::NO_CONTENT);
+    assert!(store.load_all().unwrap().is_empty());
+}
+
+#[tokio::test]
+async fn reclaim_unknown_id_returns_404() {
+    let h = spawn("naps-laptop").await;
+    let resp = reqwest::Client::new()
+        .delete(url(h.addr, &format!("/api/worktrees/{}", Uuid::new_v4())))
+        .send()
+        .await
+        .unwrap();
+    assert_eq!(resp.status(), reqwest::StatusCode::NOT_FOUND);
+}
+
+#[tokio::test]
+async fn worktrees_prunes_entries_whose_directory_vanished_by_hand() {
+    let h = spawn("naps-laptop").await;
+    let fx = retained_fixture();
+    let store = h._fx.retained_store();
+    store
+        .retain(
+            &fx.wt,
+            fx.repo.path(),
+            "feat/login",
+            maestro_daemon::retained_store::RetainedReason::ForceKilled,
+        )
+        .unwrap();
+    std::fs::remove_dir_all(&fx.wt).unwrap();
+
+    let listed: Vec<maestro_protocol::RetainedWorktree> =
+        reqwest::get(url(h.addr, "/api/worktrees"))
+            .await
+            .unwrap()
+            .json()
+            .await
+            .unwrap();
+    assert!(listed.is_empty(), "a hand-removed directory is not listed");
+    assert!(
+        store.load_all().unwrap().is_empty(),
+        "and its entry is gone"
+    );
+}

crates/maestro-daemon/tests/session_decisions.rs

@@ -211,7 +211,7 @@ async fn killing_a_dead_session_dismisses_it_without_touching_tmux() {
     fx.manager.start_liveness_watcher(Duration::from_millis(25));
     wait_for_status(&fx.manager, s.id, SessionStatus::Dead).await;
 
-    fx.manager.kill(s.id).await.expect("dismiss");
+    fx.manager.kill(s.id, false).await.expect("dismiss");
 
     assert!(fx.manager.snapshot().await.is_empty());
     assert!(
@@ -371,7 +371,7 @@ async fn killing_an_unknown_session_is_reported_as_not_found() {
     let fx = Fx::new();
     let err = fx
         .manager
-        .kill(uuid::Uuid::new_v4())
+        .kill(uuid::Uuid::new_v4(), false)
         .await
         .expect_err("should fail");
     assert_eq!(err.to_error_info().code, "not_found");

crates/maestro-daemon/tests/session_manager.rs

@@ -4,10 +4,14 @@ mod common;
 
 use std::collections::HashMap;
 use std::path::PathBuf;
+use std::process::Command;
 use std::sync::Arc;
 use std::time::Duration;
 
-use common::{init_repo, wait_for_async, DaemonFixture};
+use common::{
+    init_bare_repo, init_repo, push_all_to_origin, wait_for_async, DaemonFixture, TmuxFixture,
+};
+use maestro_daemon::SessionError;
 use maestro_protocol::CreateSessionRequest;
 use maestro_protocol::{CatalogEvent, SessionStatus, WorktreeSpec};
 use tempfile::TempDir;
@@ -42,7 +46,7 @@ async fn create_then_kill_round_trip() {
     // FIFO should also exist
     assert!(fx.fifo_dir().join(format!("{}.fifo", session.id)).exists());
 
-    fx.manager.kill(session.id).await.expect("kill");
+    fx.manager.kill(session.id, false).await.expect("kill");
     assert!(!fx.manager.has(session.id).await);
     assert!(!fx
         .sidecar_dir()
@@ -77,7 +81,7 @@ async fn create_appends_to_spawn_history() {
     assert_eq!(recents[0].cwd, cwd.path());
     assert_eq!(recents[0].last_command, "sleep 30");
 
-    fx.manager.kill(session.id).await.expect("kill");
+    fx.manager.kill(session.id, false).await.expect("kill");
     // History is durable — it survives the kill that deletes the sidecar.
     assert_eq!(fx.manager.recent_dirs().len(), 1);
 }
@@ -183,7 +187,7 @@ async fn create_captures_initial_output_in_replay_buffer() {
         "first-line marker never reached the replay buffer — pipe-pane raced past the child's initial output",
     );
 
-    fx.manager.kill(s.id).await.unwrap();
+    fx.manager.kill(s.id, false).await.unwrap();
 }
 
 /// Regression for NAP-228: after `recover`, PTY output must reach new
@@ -249,7 +253,7 @@ async fn recover_re_pipes_pane_so_output_reaches_subscribers() {
         String::from_utf8_lossy(&buf),
     );
 
-    revived.kill(s.id).await.unwrap();
+    revived.kill(s.id, false).await.unwrap();
 }
 
 #[tokio::test]
@@ -298,7 +302,7 @@ async fn pty_broadcast_delivers_bytes_to_subscribers() {
     assert!(buf_a.windows(want.len()).any(|w| w == want), "A missed");
     assert!(buf_b.windows(want.len()).any(|w| w == want), "B missed");
 
-    fx.manager.kill(s.id).await.unwrap();
+    fx.manager.kill(s.id, false).await.unwrap();
     let _ = (cwd, PathBuf::from("/"));
 }
 
@@ -357,20 +361,82 @@ async fn liveness_watcher_marks_dead_sessions_and_keeps_them_until_dismissed() {
     );
 
     // Dismissing it is what finally releases the artifacts.
-    fx.manager.kill(s.id).await.expect("dismiss");
+    fx.manager.kill(s.id, false).await.expect("dismiss");
     assert!(!fx.manager.has(s.id).await);
     assert!(!fx.sidecar_dir().join(format!("{}.json", s.id)).exists());
     assert!(!fx.fifo_dir().join(format!("{}.fifo", s.id)).exists());
 }
 
-/// Cleanup is unconditional (#56): even a spec that says "don't clean up"
-/// loses its worktree on kill — the guard, not the flag, protects work.
+/// #83: the watcher refreshes `Session.blocked_work` on its own cadence —
+/// first "nothing blocks" for a pristine tree, then the breakdown once the
+/// tree picks up unsaved work, so clients can warn before the kill attempt.
+#[tokio::test]
+async fn watcher_refreshes_the_blocked_work_indicator() {
+    let fx = DaemonFixture::new();
+    let repo = TempDir::new().unwrap();
+    init_repo(repo.path());
+    let wt_path = repo.path().join("worktrees").join("feat").join("indicator");
+
+    fx.manager
+        .create(CreateSessionRequest {
+            cwd: repo.path().to_path_buf(),
+            command: "sleep 30".into(),
+            env: HashMap::new(),
+            metadata: HashMap::new(),
+            worktree: Some(WorktreeSpec {
+                base_repo: repo.path().to_path_buf(),
+                branch: "feat/indicator".into(),
+                create_branch: true,
+            }),
+        })
+        .await
+        .expect("create");
+
+    // Pushed and clean: nothing in the way, and the indicator must say so.
+    let origin = TempDir::new().unwrap();
+    init_bare_repo(origin.path());
+    push_all_to_origin(repo.path(), origin.path());
+
+    fx.manager.start_liveness_watcher_with_blocked_work(
+        Duration::from_millis(50),
+        Duration::from_millis(100),
+    );
+
+    wait_for_async(Duration::from_secs(5), || async {
+        fx.manager.snapshot().await[0].blocked_work == Some(maestro_protocol::InTheWay::default())
+    })
+    .await;
+
+    // Unsaved work appears; the next pass must surface it.
+    std::fs::write(wt_path.join("README"), b"unsaved edits\n").unwrap();
+    std::fs::write(wt_path.join("notes.txt"), b"untracked\n").unwrap();
+    wait_for_async(Duration::from_secs(5), || async {
+        matches!(
+            &fx.manager.snapshot().await[0].blocked_work,
+            Some(b) if b.uncommitted_files >= 1 && b.untracked_files >= 1
+        )
+    })
+    .await;
+
+    // A steady state must not re-emit every tick (#83 change-detection).
+    let mut events = fx.manager.events();
+    while events.try_recv().is_ok() {}
+    tokio::time::sleep(Duration::from_millis(400)).await;
+    assert!(
+        !matches!(events.try_recv(), Ok(CatalogEvent::SessionUpdated { .. })),
+        "an unchanged worktree must not re-emit SessionUpdated"
+    );
+}
+
+/// Cleanup on kill is unconditional once the guard passes (#79): even a spec
+/// that says "don't clean up" loses its worktree — the branch was pushed, so
+/// nothing in the tree is unique and removal goes ahead.
 #[tokio::test]
 async fn kill_removes_worktree_even_when_spec_says_keep() {
     let fx = DaemonFixture::new();
     let repo = TempDir::new().unwrap();
     init_repo(repo.path());
-    let wt_path = repo.path().join("worktrees").join("feat-keep");
+    let wt_path = repo.path().join("worktrees").join("feat").join("keep");
 
     let s = fx
         .manager
@@ -382,7 +448,6 @@ async fn kill_removes_worktree_even_when_spec_says_keep() {
             worktree: Some(WorktreeSpec {
                 base_repo: repo.path().to_path_buf(),
                 branch: "feat/keep".into(),
-                cleanup_on_kill: false,
                 create_branch: true,
             }),
         })
@@ -390,18 +455,25 @@ async fn kill_removes_worktree_even_when_spec_says_keep() {
         .expect("create");
     assert!(wt_path.exists());
 
-    fx.manager.kill(s.id).await.expect("kill");
+    // Push the branch so its commits are reachable from a remote-tracking ref.
+    let origin = TempDir::new().unwrap();
+    init_bare_repo(origin.path());
+    push_all_to_origin(repo.path(), origin.path());
+
+    fx.manager.kill(s.id, false).await.expect("kill");
     assert!(!wt_path.exists(), "worktree must be removed on kill");
 }
 
-/// The guard (#56): a worktree holding uncommitted changes survives the kill,
-/// left on disk where the operator can find it.
+/// The kill guard (#79): a worktree holding uncommitted changes refuses the
+/// kill outright. Nothing happens — the session keeps running as the
+/// operator's handle on their unfinished work, and the tree is untouched.
+/// The refusal names what blocked it and how much of it there is.
 #[tokio::test]
-async fn kill_leaves_worktree_with_unsaved_work_on_disk() {
+async fn killing_refuses_a_worktree_with_unsaved_work_and_keeps_the_session() {
     let fx = DaemonFixture::new();
     let repo = TempDir::new().unwrap();
     init_repo(repo.path());
-    let wt_path = repo.path().join("worktrees").join("feat-guarded");
+    let wt_path = repo.path().join("worktrees").join("feat").join("guarded");
 
     let s = fx
         .manager
@@ -413,7 +485,120 @@ async fn kill_leaves_worktree_with_unsaved_work_on_disk() {
             worktree: Some(WorktreeSpec {
                 base_repo: repo.path().to_path_buf(),
                 branch: "feat/guarded".into(),
-                cleanup_on_kill: true,
+                create_branch: true,
+            }),
+        })
+        .await
+        .expect("create");
+    std::fs::write(wt_path.join("README"), b"unsaved edits\n").unwrap();
+    std::fs::write(wt_path.join("notes.txt"), b"untracked\n").unwrap();
+
+    let err = fx
+        .manager
+        .kill(s.id, false)
+        .await
+        .expect_err("kill must refuse");
+    let SessionError::KillGuarded(breakdown) = err else {
+        panic!("expected KillGuarded, got {err:?}");
+    };
+    assert_eq!(breakdown.uncommitted_files, 1);
+    assert_eq!(breakdown.untracked_files, 1);
+    assert!(
+        breakdown.unpushed_commits >= 1,
+        "a fresh branch has no remote-tracking ref"
+    );
+    let message = breakdown.to_string();
+    assert!(message.contains("1 uncommitted file"), "{message}");
+    assert!(message.contains("1 untracked file"), "{message}");
+
+    // Nothing happened: the session survives and so does the tree.
+    assert!(fx.manager.has(s.id).await, "the session must keep running");
+    assert!(wt_path.exists(), "the worktree must be untouched");
+
+    // A second kill after the work is saved goes through.
+    run_git_in(&wt_path, &["add", "."]);
+    run_git_in(&wt_path, &["commit", "-q", "-m", "saved"]);
+    let origin = TempDir::new().unwrap();
+    init_bare_repo(origin.path());
+    push_all_to_origin(repo.path(), origin.path());
+    fx.manager
+        .kill(s.id, false)
+        .await
+        .expect("kill after saving");
+    assert!(!fx.manager.has(s.id).await);
+}
+
+/// Unpushed commits alone block the kill (#79): a feature branch almost
+/// always has them, which is why `--force` (which retains) is the ordinary
+/// way to end such a session.
+#[tokio::test]
+async fn killing_refuses_until_the_branch_is_pushed() {
+    let fx = DaemonFixture::new();
+    let repo = TempDir::new().unwrap();
+    init_repo(repo.path());
+    let wt_path = repo.path().join("worktrees").join("feat").join("pushed");
+
+    let s = fx
+        .manager
+        .create(CreateSessionRequest {
+            cwd: repo.path().to_path_buf(),
+            command: "sleep 30".into(),
+            env: HashMap::new(),
+            metadata: HashMap::new(),
+            worktree: Some(WorktreeSpec {
+                base_repo: repo.path().to_path_buf(),
+                branch: "feat/pushed".into(),
+                create_branch: true,
+            }),
+        })
+        .await
+        .expect("create");
+
+    let err = fx
+        .manager
+        .kill(s.id, false)
+        .await
+        .expect_err("unpushed blocks");
+    let SessionError::KillGuarded(breakdown) = err else {
+        panic!("expected KillGuarded, got {err:?}");
+    };
+    assert_eq!(breakdown.uncommitted_files, 0);
+    assert_eq!(breakdown.untracked_files, 0);
+    assert!(breakdown.unpushed_commits >= 1);
+
+    let origin = TempDir::new().unwrap();
+    init_bare_repo(origin.path());
+    push_all_to_origin(repo.path(), origin.path());
+
+    fx.manager
+        .kill(s.id, false)
+        .await
+        .expect("pushed branch kills");
+    assert!(!wt_path.exists());
+    assert!(!fx.manager.has(s.id).await);
+}
+
+/// `--force` overrides the refusal and nothing else (#81): the session ends,
+/// but the guarded worktree is RETAINED — never removed — and enters the
+/// retained store with reason `force-killed`. The outcome names what was
+/// kept, so a client can say where the work went.
+#[tokio::test]
+async fn force_killing_a_guarded_worktree_retains_it_in_the_store() {
+    let fx = DaemonFixture::new();
+    let repo = TempDir::new().unwrap();
+    init_repo(repo.path());
+    let wt_path = repo.path().join("worktrees").join("feat").join("forced");
+
+    let s = fx
+        .manager
+        .create(CreateSessionRequest {
+            cwd: repo.path().to_path_buf(),
+            command: "sleep 30".into(),
+            env: HashMap::new(),
+            metadata: HashMap::new(),
+            worktree: Some(WorktreeSpec {
+                base_repo: repo.path().to_path_buf(),
+                branch: "feat/forced".into(),
                 create_branch: true,
             }),
         })
@@ -421,12 +606,320 @@ async fn kill_leaves_worktree_with_unsaved_work_on_disk() {
         .expect("create");
     std::fs::write(wt_path.join("README"), b"unsaved edits\n").unwrap();
 
-    fx.manager.kill(s.id).await.expect("kill");
+    // Without force the same kill is refused (#79).
+    assert!(fx.manager.kill(s.id, false).await.is_err());
+
+    let outcome = fx
+        .manager
+        .kill(s.id, true)
+        .await
+        .expect("force overrides the refusal");
+
+    // The tree would have blocked, so force must NOT have removed it...
     assert!(
         wt_path.exists(),
-        "dirty worktree must be left on disk, not destroyed"
+        "a forced kill never removes a tree that would have blocked"
+    );
+    // ...but the session itself still ends.
+    assert!(!fx.manager.has(s.id).await);
+    assert!(!fx.sidecar_dir().join(format!("{}.json", s.id)).exists());
+
+    let retained = outcome.retained.expect("the outcome names what was kept");
+    assert_eq!(retained.path, wt_path);
+    assert_eq!(retained.branch, "feat/forced");
+    assert_eq!(
+        retained.reason,
+        maestro_protocol::RetainedReason::ForceKilled
+    );
+    assert!(
+        retained.in_the_way.uncommitted_files >= 1,
+        "the outcome carries what blocked the unforced kill"
+    );
+
+    // The store holds the same entry, so reclaim can find it later (#80).
+    let all = fx.retained_store().load_all().expect("load_all");
+    assert_eq!(all.len(), 1);
+    assert_eq!(all[0].id, retained.id);
+    assert_eq!(all[0].path, wt_path);
+    assert_eq!(all[0].branch, "feat/forced");
+}
+
+/// Force overrides the *refusal*, not ordinary cleanup (#81): a tree whose
+/// guard is clear never needed the override, so a forced kill removes it as
+/// usual and retains nothing.
+#[tokio::test]
+async fn force_on_a_clear_worktree_removes_it_as_usual() {
+    let fx = DaemonFixture::new();
+    let repo = TempDir::new().unwrap();
+    init_repo(repo.path());
+    let wt_path = repo.path().join("worktrees").join("feat").join("clear");
+
+    let s = fx
+        .manager
+        .create(CreateSessionRequest {
+            cwd: repo.path().to_path_buf(),
+            command: "sleep 30".into(),
+            env: HashMap::new(),
+            metadata: HashMap::new(),
+            worktree: Some(WorktreeSpec {
+                base_repo: repo.path().to_path_buf(),
+                branch: "feat/clear".into(),
+                create_branch: true,
+            }),
+        })
+        .await
+        .expect("create");
+
+    let origin = TempDir::new().unwrap();
+    init_bare_repo(origin.path());
+    push_all_to_origin(repo.path(), origin.path());
+
+    let outcome = fx.manager.kill(s.id, true).await.expect("kill");
+    assert!(!wt_path.exists(), "a clear tree needs no override");
+    assert_eq!(outcome.retained, None);
+    assert!(fx.retained_store().load_all().unwrap().is_empty());
+}
+
+/// Ignored files NEVER block (#79): build output like `target/` exists in
+/// every Rust checkout, and an ignored-only worktree stays killable.
+#[tokio::test]
+async fn killing_an_ignored_only_worktree_succeeds() {
+    let fx = DaemonFixture::new();
+    let repo = TempDir::new().unwrap();
+    init_repo(repo.path());
+    // .gitignore must be committed before the worktree branches off, or it
+    // would itself read as an untracked file.
+    std::fs::write(repo.path().join(".gitignore"), b"/target\n").unwrap();
+    run_git_in(repo.path(), &["add", ".gitignore"]);
+    run_git_in(repo.path(), &["commit", "-q", "-m", "ignore target"]);
+    let origin = TempDir::new().unwrap();
+    init_bare_repo(origin.path());
+
+    let wt_path = repo.path().join("worktrees").join("feat").join("rusty");
+    let s = fx
+        .manager
+        .create(CreateSessionRequest {
+            cwd: repo.path().to_path_buf(),
+            command: "sleep 30".into(),
+            env: HashMap::new(),
+            metadata: HashMap::new(),
+            worktree: Some(WorktreeSpec {
+                base_repo: repo.path().to_path_buf(),
+                branch: "feat/rusty".into(),
+                create_branch: true,
+            }),
+        })
+        .await
+        .expect("create");
+    std::fs::create_dir_all(wt_path.join("target")).unwrap();
+    std::fs::write(wt_path.join("target").join("app.o"), b"binary\n").unwrap();
+
+    // Branch pushed; the only dirt is ignored output.
+    push_all_to_origin(repo.path(), origin.path());
+
+    fx.manager
+        .kill(s.id, false)
+        .await
+        .expect("ignored files never block");
+    assert!(!wt_path.exists());
+    assert!(!fx.manager.has(s.id).await);
+}
+
+/// Natural exit (#82): a session that ends on its own never reaches the kill
+/// path, so the watcher applies the kill's rule itself. A worktree holding
+/// unsaved work is RETAINED into the store with reason
+/// `exited-with-unsaved-work`; the session stays in the catalog marked dead
+/// until dismissed — and dismissing it afterwards neither refuses nor
+/// retains a second time.
+#[tokio::test]
+async fn natural_exit_of_a_guarded_worktree_retains_it_in_the_store() {
+    let fx = DaemonFixture::new();
+    let repo = TempDir::new().unwrap();
+    init_repo(repo.path());
+    let wt_path = repo.path().join("worktrees").join("feat").join("exited");
+
+    let s = fx
+        .manager
+        .create(CreateSessionRequest {
+            cwd: repo.path().to_path_buf(),
+            command: "sleep 30".into(),
+            env: HashMap::new(),
+            metadata: HashMap::new(),
+            worktree: Some(WorktreeSpec {
+                base_repo: repo.path().to_path_buf(),
+                branch: "feat/exited".into(),
+                create_branch: true,
+            }),
+        })
+        .await
+        .expect("create");
+    std::fs::write(wt_path.join("README"), b"unsaved edits\n").unwrap();
+
+    // The command finishes / the operator types exit: tmux loses the session.
+    fx.tmux.tmux.kill_session(s.id).expect("kill tmux directly");
+    fx.manager.start_liveness_watcher(Duration::from_millis(50));
+    wait_for_async(Duration::from_secs(3), || async {
+        fx.manager.status(s.id).await == Some(SessionStatus::Dead)
+    })
+    .await;
+
+    // The tree would have blocked a kill, so the exit kept it...
+    assert!(
+        wt_path.exists(),
+        "a dirty worktree must be retained on natural exit"
+    );
+    // ...in the store, under the exit reason.
+    let all = fx.retained_store().load_all().expect("load_all");
+    assert_eq!(all.len(), 1);
+    assert_eq!(all[0].path, wt_path);
+    assert_eq!(all[0].branch, "feat/exited");
+    assert_eq!(
+        all[0].reason,
+        maestro_protocol::RetainedReason::ExitedWithUnsavedWork
+    );
+
+    // The session itself stays until dismissed; its worktree reference is
+    // settled, so dismissal is neither refused nor retained twice.
+    // (`Dead` is observable a moment before the settle step finishes.)
+    wait_for_async(Duration::from_secs(3), || async {
+        let s = &fx.manager.snapshot().await[0];
+        s.worktree.is_none() && s.blocked_work.is_none()
+    })
+    .await;
+    let snap = fx.manager.snapshot().await;
+    assert_eq!(snap.len(), 1);
+    assert_eq!(snap[0].worktree, None);
+
+    fx.manager.kill(s.id, false).await.expect("dismiss");
+    assert!(!fx.manager.has(s.id).await);
+    assert!(
+        wt_path.exists(),
+        "dismissal must not remove what was retained"
+    );
+    assert_eq!(
+        fx.retained_store().load_all().unwrap().len(),
+        1,
+        "dismissal must not record a second entry for the same tree"
+    );
+}
+
+/// Natural exit (#82), pristine side of the same rule: nothing in the tree,
+/// nothing to keep — the worktree is removed and no store entry appears.
+#[tokio::test]
+async fn natural_exit_of_a_pristine_worktree_removes_it() {
+    let fx = DaemonFixture::new();
+    let repo = TempDir::new().unwrap();
+    init_repo(repo.path());
+    let wt_path = repo.path().join("worktrees").join("feat").join("clean");
+
+    let s = fx
+        .manager
+        .create(CreateSessionRequest {
+            cwd: repo.path().to_path_buf(),
+            command: "sleep 30".into(),
+            env: HashMap::new(),
+            metadata: HashMap::new(),
+            worktree: Some(WorktreeSpec {
+                base_repo: repo.path().to_path_buf(),
+                branch: "feat/clean".into(),
+                create_branch: true,
+            }),
+        })
+        .await
+        .expect("create");
+
+    // Push everything so the branch has no unpushed commits: fully pristine.
+    let origin = TempDir::new().unwrap();
+    init_bare_repo(origin.path());
+    push_all_to_origin(repo.path(), origin.path());
+
+    fx.tmux.tmux.kill_session(s.id).expect("kill tmux directly");
+    fx.manager.start_liveness_watcher(Duration::from_millis(50));
+    wait_for_async(Duration::from_secs(3), || async {
+        fx.manager.status(s.id).await == Some(SessionStatus::Dead)
+    })
+    .await;
+
+    assert!(
+        !wt_path.exists(),
+        "a pristine worktree leaves nothing behind"
+    );
+    assert!(
+        fx.retained_store().load_all().unwrap().is_empty(),
+        "nothing was retained"
+    );
+    assert!(
+        fx.manager.has(s.id).await,
+        "the session stays until dismissed"
+    );
+}
+
+/// When nothing can be recorded — here: no retained store wired — the exit
+/// destroys nothing. The tree stays on disk AND stays attached to the dead
+/// record, where dismissing it later still goes through #81's forced-kill
+/// retention. Losing the store must not lose the work.
+#[tokio::test]
+async fn natural_exit_without_a_retained_store_destroys_nothing() {
+    let tmux = TmuxFixture::new();
+    let state_dir = TempDir::new().unwrap();
+    let manager = maestro_daemon::SessionManager::new(
+        Arc::new(tmux.tmux.clone()),
+        maestro_daemon::sidecar::SidecarStore::new(state_dir.path().join("sessions")),
+        maestro_daemon::worktree::WorktreeManager::new(None),
+        state_dir.path().join("fifos"),
+    );
+    // Deliberately NO with_retained_store.
+
+    let repo = TempDir::new().unwrap();
+    init_repo(repo.path());
+    let wt_path = repo.path().join("worktrees").join("feat").join("nostore");
+
+    let s = manager
+        .create(CreateSessionRequest {
+            cwd: repo.path().to_path_buf(),
+            command: "sleep 30".into(),
+            env: HashMap::new(),
+            metadata: HashMap::new(),
+            worktree: Some(WorktreeSpec {
+                base_repo: repo.path().to_path_buf(),
+                branch: "feat/nostore".into(),
+                create_branch: true,
+            }),
+        })
+        .await
+        .expect("create");
+    std::fs::write(wt_path.join("README"), b"unsaved edits\n").unwrap();
+
+    tmux.tmux.kill_session(s.id).expect("kill tmux directly");
+    manager.start_liveness_watcher(Duration::from_millis(50));
+    wait_for_async(Duration::from_secs(3), || async {
+        manager.status(s.id).await == Some(SessionStatus::Dead)
+    })
+    .await;
+
+    assert!(
+        wt_path.exists(),
+        "nothing may be destroyed when it cannot be recorded"
+    );
+    let snap = manager.snapshot().await;
+    assert!(
+        snap[0].worktree.is_some(),
+        "the tree must stay attached to the record so a later forced kill can retain it"
+    );
+}
+
+fn run_git_in(dir: &std::path::Path, args: &[&str]) {
+    let out = Command::new("git")
+        .arg("-C")
+        .arg(dir)
+        .args(args)
+        .output()
+        .expect("git spawn");
+    assert!(
+        out.status.success(),
+        "git {args:?} failed: {}",
+        String::from_utf8_lossy(&out.stderr)
     );
-    assert!(fx.manager.snapshot().await.is_empty());
 }
 
 #[tokio::test]
@@ -452,5 +945,5 @@ async fn liveness_watcher_leaves_running_sessions_alone() {
     tokio::time::sleep(Duration::from_millis(400)).await;
     assert!(fx.manager.has(s.id).await, "live session got reaped");
 
-    fx.manager.kill(s.id).await.unwrap();
+    fx.manager.kill(s.id, false).await.unwrap();
 }

crates/maestro-daemon/tests/sidecar.rs

@@ -19,6 +19,7 @@ fn sample(id: Uuid) -> Session {
         command: "bash".into(),
         env: HashMap::from([("FOO".into(), "bar".into())]),
         metadata: HashMap::from([("name".into(), Value::String("maestro-impl".into()))]),
+        worktree: None,
         status: SessionStatus::Running,
         created_at: DateTime::parse_from_rfc3339("2026-05-24T12:00:00Z")
             .unwrap()
@@ -27,6 +28,7 @@ fn sample(id: Uuid) -> Session {
         activity: Default::default(),
         last_activity_at: chrono::Utc::now(),
         current_cwd: Some(PathBuf::from("/tmp/work/crates")),
+        blocked_work: None,
     }
 }
 

crates/maestro-daemon/tests/worktree.rs

@@ -6,8 +6,9 @@ mod common;
 use std::path::PathBuf;
 use std::process::Command;
 
-use common::init_repo;
+use common::{init_bare_repo, init_repo, push_all_to_origin};
 use maestro_daemon::worktree::WorktreeManager;
+use maestro_daemon::worktree_probe::in_the_way;
 use tempfile::TempDir;
 
 fn worktree_branches(repo: &PathBuf) -> Vec<String> {
@@ -53,7 +54,7 @@ fn add_places_worktree_inside_the_base_repo_by_default() {
     let mgr = WorktreeManager::new(None);
 
     let path = mgr.add_new(&repo, "feat/example").expect("add worktree");
-    assert_eq!(path, repo.join("worktrees").join("feat-example"));
+    assert_eq!(path, repo.join("worktrees").join("feat").join("example"));
     assert!(path.exists());
     assert!(path.join("README").exists());
 
@@ -74,31 +75,47 @@ fn worktree_root_override_redirects_placement() {
     // repos spawning the same branch name don't target one directory.
     let repo_name = repo.file_name().unwrap();
     let path = mgr.add_new(&repo, "feat/example").expect("add worktree");
-    assert_eq!(path, wt_root.path().join(repo_name).join("feat-example"));
+    // The override root disambiguates same-named checkouts with a digest of
+    // the full repo path, and the branch keeps its own shape.
+    // <root>/<repo basename>-<digest>/feat/example
+    let prefix = format!("{}-", repo_name.to_string_lossy());
+    let repo_dir_name = path
+        .strip_prefix(wt_root.path())
+        .unwrap()
+        .components()
+        .next()
+        .unwrap();
+    assert!(
+        repo_dir_name
+            .as_os_str()
+            .to_string_lossy()
+            .starts_with(&prefix),
+        "{path:?}"
+    );
+    assert!(path.ends_with("feat/example"), "{path:?}");
     assert!(path.exists());
 }
 
+/// Anything at all occupying the target path — ours, the operator's, or an
+/// unrelated directory — is sidestepped, not adopted and not reported (#77).
 #[test]
-fn existing_directory_at_target_path_is_an_error_carrying_the_path() {
+fn an_occupied_target_path_gets_a_numeric_suffix() {
     let repo_dir = TempDir::new().unwrap();
     let repo = repo_dir.path().to_path_buf();
     init_repo(&repo);
 
-    // A predictable path means collisions are possible; they must be
-    // reported, never silently relocated.
-    std::fs::create_dir_all(repo.join("worktrees").join("feat-collide")).unwrap();
+    // A non-git directory sits exactly where the worktree would go.
+    let squatter = repo.join("worktrees").join("feat").join("collide");
+    std::fs::create_dir_all(&squatter).unwrap();
+    std::fs::write(squatter.join("operator-notes.txt"), b"mine\n").unwrap();
 
     let mgr = WorktreeManager::new(None);
-    let err = mgr.add_new(&repo, "feat/collide").unwrap_err();
-    let msg = format!("{err}");
+    let path = mgr.add_new(&repo, "feat/collide").expect("sidesteps");
+    assert_eq!(path, repo.join("worktrees").join("feat").join("collide-2"));
+    assert!(path.exists());
     assert!(
-        msg.contains(
-            repo.join("worktrees")
-                .join("feat-collide")
-                .to_str()
-                .unwrap()
-        ),
-        "{msg}"
+        squatter.join("operator-notes.txt").exists(),
+        "the occupant is untouched"
     );
 }
 
@@ -118,6 +135,123 @@ fn add_twice_generates_distinct_paths() {
     assert!(p2.exists());
 }
 
+/// The unsaved-work probe (#79) counts uncommitted tracked changes.
+#[test]
+fn the_probe_counts_uncommitted_tracked_changes() {
+    let repo_dir = TempDir::new().unwrap();
+    let repo = repo_dir.path().to_path_buf();
+    init_repo(&repo);
+
+    let mgr = WorktreeManager::new(None);
+    let path = mgr.add_new(&repo, "feat/dirty").expect("add");
+    std::fs::write(path.join("README"), b"unsaved edits\n").unwrap();
+
+    let w = in_the_way(&path).expect("probe");
+    assert_eq!(w.uncommitted_files, 1);
+    assert_eq!(w.untracked_files, 0);
+}
+
+/// Untracked sources count; a staged new file is also unsaved tracked work.
+#[test]
+fn the_probe_counts_untracked_files() {
+    let repo_dir = TempDir::new().unwrap();
+    let repo = repo_dir.path().to_path_buf();
+    init_repo(&repo);
+
+    let mgr = WorktreeManager::new(None);
+    let path = mgr.add_new(&repo, "feat/untracked").expect("add");
+    std::fs::write(path.join("notes.txt"), b"wip\n").unwrap();
+    std::fs::write(path.join("more.txt"), b"also wip\n").unwrap();
+
+    let w = in_the_way(&path).expect("probe");
+    assert_eq!(w.untracked_files, 2);
+    assert_eq!(w.uncommitted_files, 0);
+
+    run_git(&path, &["add", "notes.txt"]);
+    let w = in_the_way(&path).expect("probe");
+    assert_eq!(w.uncommitted_files, 1, "staged counts as uncommitted");
+    assert_eq!(w.untracked_files, 1);
+}
+
+/// Ignored files NEVER block: every Rust checkout has a `target/`, and
+/// counting ignored output would leave no session killable (#79).
+#[test]
+fn the_probe_ignores_ignored_files() {
+    let repo_dir = TempDir::new().unwrap();
+    let repo = repo_dir.path().to_path_buf();
+    init_repo(&repo);
+
+    // .gitignore must be committed, or it would itself read as untracked.
+    std::fs::write(repo.join(".gitignore"), b"/target\n").unwrap();
+    run_git(&repo, &["add", ".gitignore"]);
+    run_git(&repo, &["commit", "-q", "-m", "ignore target"]);
+
+    let mgr = WorktreeManager::new(None);
+    let path = mgr.add_new(&repo, "feat/builds").expect("add");
+    std::fs::create_dir_all(path.join("target")).unwrap();
+    std::fs::write(path.join("target").join("app.o"), b"binary\n").unwrap();
+
+    let w = in_the_way(&path).expect("probe");
+    assert_eq!(w.uncommitted_files, 0);
+    assert_eq!(w.untracked_files, 0);
+
+    // With the branch pushed too, an ignored-only tree reads fully clean.
+    let origin_dir = TempDir::new().unwrap();
+    init_bare_repo(origin_dir.path());
+    push_all_to_origin(&repo, origin_dir.path());
+    let w = in_the_way(&path).expect("probe after push");
+    assert!(w.is_clear(), "ignored-only worktree must read clean: {w:?}");
+}
+
+/// Commits reachable from no remote-tracking ref block; pushing the branch
+/// clears them. With no remote at all every commit is unreachable from one,
+/// which is exactly why feature branches almost always refuse (#79).
+#[test]
+fn the_probe_counts_unpushed_commits_until_the_branch_is_pushed() {
+    let repo_dir = TempDir::new().unwrap();
+    let repo = repo_dir.path().to_path_buf();
+    init_repo(&repo);
+
+    let mgr = WorktreeManager::new(None);
+    let path = mgr.add_new(&repo, "feat/branch").expect("add");
+
+    let w = in_the_way(&path).expect("probe");
+    assert!(
+        w.unpushed_commits >= 1,
+        "a fresh branch has no remote-tracking ref: {w:?}"
+    );
+
+    let origin_dir = TempDir::new().unwrap();
+    init_bare_repo(origin_dir.path());
+    push_all_to_origin(&repo, origin_dir.path());
+
+    let w = in_the_way(&path).expect("probe after push");
+    assert_eq!(w.unpushed_commits, 0, "{w:?}");
+    assert!(w.is_clear(), "pushed and clean must be empty: {w:?}");
+}
+
+/// The full breakdown names each blocker with its count.
+#[test]
+fn the_probe_reports_every_blocker_at_once() {
+    let repo_dir = TempDir::new().unwrap();
+    let repo = repo_dir.path().to_path_buf();
+    init_repo(&repo);
+
+    let mgr = WorktreeManager::new(None);
+    let path = mgr.add_new(&repo, "feat/mixed").expect("add");
+    std::fs::write(path.join("README"), b"edited\n").unwrap();
+    std::fs::write(path.join("scratch.txt"), b"untracked\n").unwrap();
+
+    let w = in_the_way(&path).expect("probe");
+    assert_eq!(w.uncommitted_files, 1);
+    assert_eq!(w.untracked_files, 1);
+    assert!(w.unpushed_commits >= 1);
+    let summary = w.to_string();
+    assert!(summary.contains("1 uncommitted file"), "{summary}");
+    assert!(summary.contains("1 untracked file"), "{summary}");
+    assert!(summary.contains("unpushed commit"), "{summary}");
+}
+
 #[test]
 fn remove_prunes_worktree() {
     let repo_dir = TempDir::new().unwrap();
@@ -195,8 +329,14 @@ fn add_existing_checks_out_branch_without_creating_it() {
     );
 }
 
+/// Removal is guarded upstream now (#79): the kill refuses unsaved work
+/// before anything is torn down, so by the time `remove` runs the tree is
+/// clean. Git still refuses a dirty tree on its own — this asserts that last
+/// line of defense — and committed-but-unpushed work does not block removal,
+/// because `worktree remove` keeps `refs/heads/<branch>` and the commits stay
+/// reachable.
 #[test]
-fn remove_refuses_worktree_with_uncommitted_changes() {
+fn remove_still_relies_on_git_refusing_a_dirty_tree() {
     let repo_dir = TempDir::new().unwrap();
     let repo = repo_dir.path().to_path_buf();
     init_repo(&repo);
@@ -209,10 +349,6 @@ fn remove_refuses_worktree_with_uncommitted_changes() {
         .expect_err("dirty worktree must be refused");
     assert!(path.exists(), "guarded worktree must stay on disk");
 
-    // Committing it makes removal safe: `worktree remove` keeps
-    // `refs/heads/feat/dirty`, so the work is still reachable. Refusing here
-    // instead would make every unpushed branch a one-shot, since the path is
-    // deterministic and the leftover tree blocks the next spawn (#56 review).
     run_git(&path, &["add", "."]);
     run_git(&path, &["commit", "-q", "-m", "saved"]);
 
@@ -312,10 +448,9 @@ fn placement_resolves_a_linked_worktree_to_the_main_checkout() {
         !inner.starts_with(&outer),
         "must not nest: {inner:?} inside {outer:?}"
     );
-    assert_eq!(
-        inner.parent().and_then(|p| p.parent()),
-        Some(repo.canonicalize().unwrap().as_path()),
-        "placed against the main checkout"
+    assert!(
+        inner.starts_with(repo.canonicalize().unwrap().join("worktrees")),
+        "placed against the main checkout: {inner:?}"
     );
 }
 
@@ -363,3 +498,75 @@ fn override_root_keeps_repos_apart() {
     let b = mgr.add_new(b_dir.path(), "feat/shared").expect("repo b");
     assert_ne!(a, b, "same branch name in two repos must not collide");
 }
+
+/// Flattening `/` and `.` to `-` made these three share one directory, so the
+/// losers could never get a worktree (#54 review).
+#[test]
+fn similar_branch_names_get_distinct_directories() {
+    let repo_dir = TempDir::new().unwrap();
+    let repo = repo_dir.path().to_path_buf();
+    init_repo(&repo);
+
+    let mgr = WorktreeManager::new(None);
+    let a = mgr.add_new(&repo, "feat/x").expect("feat/x");
+    let b = mgr.add_new(&repo, "feat.x").expect("feat.x");
+    let c = mgr.add_new(&repo, "feat-x").expect("feat-x");
+    assert_ne!(a, b);
+    assert_ne!(b, c);
+    assert_ne!(a, c);
+    assert!(a.ends_with("feat/x"), "{a:?}");
+}
+
+/// A guarded leftover stays on disk untouched, and is never adopted (#77).
+/// Re-spawning its branch is refused by git itself — the branch is still
+/// checked out inside the leftover — which the caller surfaces.
+#[test]
+fn a_guarded_leftover_is_never_adopted() {
+    let repo_dir = TempDir::new().unwrap();
+    let repo = repo_dir.path().to_path_buf();
+    init_repo(&repo);
+
+    let mgr = WorktreeManager::new(None);
+    let first = mgr.add_new(&repo, "feat/resume").expect("add");
+    std::fs::write(first.join("notes.txt"), b"unsaved\n").unwrap();
+
+    // Removal is refused — git itself refuses a dirty tree — leaving it on
+    // disk; the daemon-side guard lives on the kill (#79).
+    mgr.remove(&repo, &first)
+        .expect_err("dirty tree is guarded");
+
+    let err = mgr
+        .add_existing(&repo, "feat/resume")
+        .expect_err("a branch already checked out cannot be spawned twice");
+    assert!(format!("{err}").contains("git exited"), "{err}");
+    assert!(
+        first.join("notes.txt").exists(),
+        "the leftover's unsaved work is untouched"
+    );
+}
+
+/// The `worktree_root` override gets the same collision suffix (#77).
+#[test]
+fn the_override_root_suffixes_collisions_too() {
+    let repo_dir = TempDir::new().unwrap();
+    let repo = repo_dir.path().to_path_buf();
+    init_repo(&repo);
+
+    let wt_root = TempDir::new().unwrap();
+    let mgr = WorktreeManager::new(Some(wt_root.path().to_path_buf()));
+
+    // First add settles `<root>/<repo basename>-<digest>/` so the squatter
+    // can be created at the exact target.
+    mgr.add_new(&repo, "feat/first").expect("add first");
+    let repo_dir_in_root = std::fs::read_dir(wt_root.path())
+        .unwrap()
+        .next()
+        .unwrap()
+        .unwrap()
+        .path();
+    let squatter = repo_dir_in_root.join("feat").join("collide");
+    std::fs::create_dir_all(&squatter).unwrap();
+
+    let path = mgr.add_new(&repo, "feat/collide").expect("sidesteps");
+    assert_eq!(path, squatter.with_file_name("collide-2"), "{path:?}");
+}

crates/maestro-e2e/src/client.rs

@@ -11,7 +11,10 @@ use std::sync::Arc;
 use std::time::Duration;
 
 use futures_util::{SinkExt, StreamExt};
-use maestro_protocol::{CatalogEvent, CreateSessionRequest, DaemonClient, Session};
+use maestro_protocol::{
+    BranchInfo, CatalogEvent, CreateSessionRequest, DaemonClient, KillOutcome, Project,
+    RetainedWorktree, Session,
+};
 use tokio_tungstenite::tungstenite::client::IntoClientRequest;
 use tokio_tungstenite::tungstenite::Message as WsMessage;
 use tokio_tungstenite::{connect_async, MaybeTlsStream, WebSocketStream};
@@ -59,7 +62,29 @@ impl TestClient {
     }
 
     pub async fn kill_session(&self, id: Uuid) -> Result<(), ClientError> {
-        Ok(self.daemon.kill_session(id).await?)
+        Ok(self.daemon.kill_session(id, false).await.map(|_| ())?)
+    }
+
+    /// Kill with `force=true`: overrides a kill refusal and retains the
+    /// guarded worktree (#81). Answers with what was kept.
+    pub async fn kill_session_forced(&self, id: Uuid) -> Result<KillOutcome, ClientError> {
+        Ok(self.daemon.kill_session(id, true).await?)
+    }
+
+    pub async fn list_worktrees(&self) -> Result<Vec<RetainedWorktree>, ClientError> {
+        Ok(self.daemon.list_worktrees().await?)
+    }
+
+    pub async fn reclaim_worktree(&self, id: Uuid) -> Result<(), ClientError> {
+        Ok(self.daemon.reclaim_worktree(id).await?)
+    }
+
+    pub async fn list_projects(&self) -> Result<Vec<Project>, ClientError> {
+        Ok(self.daemon.list_projects().await?)
+    }
+
+    pub async fn list_branches(&self, path: &str) -> Result<Vec<BranchInfo>, ClientError> {
+        Ok(self.daemon.list_branches(path).await?)
     }
 
     /// Connect to the daemon's per-session WS and return the stream. The

crates/maestro-e2e/src/daemon.rs

@@ -29,11 +29,32 @@ impl Daemon {
         Self::spawn_at(SocketAddr::from((Ipv4Addr::LOCALHOST, free_port()))).await
     }
 
+    /// Spawn with a config file pre-seeded at the daemon's expected path
+    /// (`$XDG_CONFIG_HOME/maestro/config.toml`).
+    pub async fn spawn_with_config(toml: &str) -> Self {
+        Self::spawn_config_at(
+            SocketAddr::from((Ipv4Addr::LOCALHOST, free_port())),
+            Some(toml),
+        )
+        .await
+    }
+
     /// Spawn on a caller-supplied bind address.
     pub async fn spawn_at(bind: SocketAddr) -> Self {
+        Self::spawn_config_at(bind, None).await
+    }
+
+    /// Spawn on a caller-supplied bind address, with an optional config file.
+    async fn spawn_config_at(bind: SocketAddr, config: impl Into<Option<&str>>) -> Self {
         let home = TempDir::new().expect("home tmpdir");
         let tmux = TempDir::new().expect("tmux tmpdir");
 
+        if let Some(toml) = config.into() {
+            let dir = home.path().join(".config").join("maestro");
+            std::fs::create_dir_all(&dir).expect("config dir");
+            std::fs::write(dir.join("config.toml"), toml).expect("write config.toml");
+        }
+
         let child = launch(bind, home.path(), tmux.path());
         let me = Self {
             bind_addr: bind,

crates/maestro-e2e/src/lib.rs

@@ -14,5 +14,5 @@ pub mod daemon;
 pub mod util;
 
 pub use build::workspace_target_bin;
-pub use client::TestClient;
+pub use client::{ClientError, TestClient};
 pub use daemon::Daemon;

crates/maestro-e2e/tests/e2e.rs

@@ -35,6 +35,28 @@ fn create_req(cwd: &std::path::Path, command: &str) -> CreateSessionRequest {
     }
 }
 
+/// A worktree spec built through its wire shape. The daemon and clients ship
+/// together (#87 dropped `cleanup_on_kill` from the struct), so the JSON
+/// object carries only the fields the lifecycle actually honours.
+fn worktree_spec(base_repo: &std::path::Path, branch: &str, create_branch: bool) -> WorktreeSpec {
+    WorktreeSpec {
+        base_repo: base_repo.to_path_buf(),
+        branch: branch.into(),
+        create_branch,
+    }
+}
+
+/// Spawn request carrying a worktree spec against `base`.
+fn worktree_req(base: &std::path::Path, branch: &str, create_branch: bool) -> CreateSessionRequest {
+    CreateSessionRequest {
+        cwd: base.to_path_buf(),
+        command: "sleep 30".into(),
+        env: HashMap::new(),
+        metadata: HashMap::new(),
+        worktree: Some(worktree_spec(base, branch, create_branch)),
+    }
+}
+
 #[tokio::test(flavor = "multi_thread")]
 async fn lists_spawned_sessions() {
     let (_daemon, client) = bring_up().await;
@@ -125,12 +147,7 @@ async fn kill_removes_clean_worktree() {
         command: "sleep 30".into(),
         env: HashMap::new(),
         metadata: HashMap::new(),
-        worktree: Some(WorktreeSpec {
-            base_repo: base.path().to_path_buf(),
-            branch: "feature/e2e".into(),
-            cleanup_on_kill: true,
-            create_branch: true,
-        }),
+        worktree: Some(worktree_spec(base.path(), "feature/e2e", true)),
     };
 
     let s = client.spawn_session(&req).await.expect("spawn worktree");
@@ -140,10 +157,11 @@ async fn kill_removes_clean_worktree() {
     assert!(
         worktrees
             .iter()
-            .any(|w| w.contains("worktrees/feature-e2e")),
+            .any(|w| w.contains("worktrees/feature/e2e")),
         "expected a worktree for feature/e2e under <repo>/worktrees, got: {worktrees:?}"
     );
 
+    let _origin = throwaway_origin(base.path());
     client.kill_session(s.id).await.expect("kill");
 
     // Give the daemon a moment to remove the worktree, then verify.
@@ -161,49 +179,70 @@ async fn kill_removes_clean_worktree() {
     );
 }
 
-/// The guard (#56): killing a session whose worktree holds uncommitted
-/// changes must leave the tree on disk — cleanup is unconditional, so this
-/// guard is what keeps a stray kill from destroying work.
+/// The kill guard (#79): killing a session whose worktree holds uncommitted
+/// changes is refused outright. Nothing happens — the session keeps running
+/// as the operator's handle on their unfinished work, the tree stays on disk,
+/// and the refusal names what blocked it and how much.
 #[tokio::test(flavor = "multi_thread")]
-async fn kill_spares_worktree_with_uncommitted_changes() {
+async fn kill_refuses_worktree_with_uncommitted_changes() {
     let (_daemon, client) = bring_up().await;
 
     let base = TempDir::new().unwrap();
     init_repo(base.path());
-    let wt_path = base.path().join("worktrees").join("feature-unsaved");
+    let wt_path = base
+        .path()
+        .join("worktrees")
+        .join("feature")
+        .join("unsaved");
 
     let req = CreateSessionRequest {
         cwd: base.path().to_path_buf(),
         command: "sleep 30".into(),
         env: HashMap::new(),
         metadata: HashMap::new(),
-        worktree: Some(WorktreeSpec {
-            base_repo: base.path().to_path_buf(),
-            branch: "feature/unsaved".into(),
-            cleanup_on_kill: true,
-            create_branch: true,
-        }),
+        worktree: Some(worktree_spec(base.path(), "feature/unsaved", true)),
     };
 
     let s = client.spawn_session(&req).await.expect("spawn worktree");
     assert!(wt_path.exists());
     std::fs::write(wt_path.join("README"), b"unsaved edits\n").unwrap();
 
-    client.kill_session(s.id).await.expect("kill");
-
-    // The session is gone but the dirty worktree stays findable on disk.
-    let deadline = Instant::now() + Duration::from_secs(5);
-    while Instant::now() < deadline {
-        let sessions = client.list_sessions().await.unwrap_or_default();
-        if sessions.is_empty() {
-            break;
+    let err = client
+        .kill_session(s.id)
+        .await
+        .expect_err("kill must refuse");
+    match err {
+        maestro_e2e::ClientError::Api(maestro_protocol::ClientError::Api { info, .. }) => {
+            assert_eq!(info.code, "kill_guarded", "{info:?}");
+            let breakdown = info.unsaved_work.expect("breakdown on the wire");
+            assert_eq!(breakdown.uncommitted_files, 1);
         }
-        tokio::time::sleep(Duration::from_millis(100)).await;
+        other => panic!("expected a kill_guarded refusal, got {other:?}"),
     }
+
+    // The session survives and the dirty worktree stays findable on disk.
+    let sessions = client.list_sessions().await.unwrap_or_default();
+    assert!(
+        sessions.iter().any(|x| x.id == s.id),
+        "a refused kill must keep the session alive"
+    );
     assert!(
         wt_path.exists(),
         "guarded worktree must be left on disk after kill"
     );
+    // Left findable, not silently half-deleted: git still registers it and
+    // the uncommitted edit survives byte for byte (#66).
+    assert!(
+        git_worktree_list(base.path())
+            .iter()
+            .any(|w| w.contains("feature/unsaved")),
+        "guarded worktree must stay registered in git worktree list"
+    );
+    assert_eq!(
+        std::fs::read(wt_path.join("README")).unwrap(),
+        b"unsaved edits\n",
+        "uncommitted changes must survive the guarded kill"
+    );
 }
 
 #[tokio::test(flavor = "multi_thread")]
@@ -219,12 +258,7 @@ async fn spawn_on_existing_branch_checks_it_out() {
         command: "sleep 30".into(),
         env: HashMap::new(),
         metadata: HashMap::new(),
-        worktree: Some(WorktreeSpec {
-            base_repo: base.path().to_path_buf(),
-            branch: "feature/existing".into(),
-            cleanup_on_kill: true,
-            create_branch: false,
-        }),
+        worktree: Some(worktree_spec(base.path(), "feature/existing", false)),
     };
 
     let s = client
@@ -237,9 +271,761 @@ async fn spawn_on_existing_branch_checks_it_out() {
         "expected a worktree checked out at feature/existing, got: {worktrees:?}"
     );
 
+    let _origin = throwaway_origin(base.path());
     client.kill_session(s.id).await.expect("kill");
 }
 
+/// #66: a fresh branch spawns a worktree at `<repo>/worktrees/<branch>` and
+/// the session actually runs inside it — `current_cwd` comes from tmux's live
+/// pane state, not from the spawn request.
+#[tokio::test(flavor = "multi_thread")]
+async fn spawn_new_branch_creates_worktree_and_runs_in_it() {
+    let (_daemon, client) = bring_up().await;
+
+    let base = TempDir::new().unwrap();
+    init_repo(base.path());
+    let wt_path = base.path().join("worktrees").join("feature").join("fresh");
+
+    let s = client
+        .spawn_session(&worktree_req(base.path(), "feature/fresh", true))
+        .await
+        .expect("spawn new-branch worktree");
+
+    assert_eq!(
+        s.cwd, wt_path,
+        "session must report the worktree as its cwd"
+    );
+    assert!(wt_path.is_dir(), "worktree directory must exist on disk");
+
+    // The activity watcher fills `current_cwd` from tmux's pane_current_path,
+    // so this is the daemon confirming where the process really runs.
+    wait_for_async(
+        "session's live cwd is the worktree",
+        Duration::from_secs(20),
+        || {
+            let client = client.clone();
+            let id = s.id;
+            let want = wt_path.clone();
+            async move {
+                client
+                    .list_sessions()
+                    .await
+                    .ok()
+                    .and_then(|ss| ss.iter().find(|s| s.id == id).cloned())
+                    .map(|s| s.current_cwd == Some(want.clone()))
+                    .unwrap_or(false)
+            }
+        },
+    )
+    .await;
+
+    let _origin = throwaway_origin(base.path());
+    client.kill_session(s.id).await.expect("kill");
+}
+
+/// #66: a second spawn onto a branch that already has a worktree is rejected
+/// with a structured worktree error; the first worktree stays intact.
+#[tokio::test(flavor = "multi_thread")]
+async fn second_spawn_on_same_branch_is_rejected() {
+    let (_daemon, client) = bring_up().await;
+
+    let base = TempDir::new().unwrap();
+    init_repo(base.path());
+
+    let first = client
+        .spawn_session(&worktree_req(base.path(), "feature/dup", true))
+        .await
+        .expect("first spawn");
+    let dup = client
+        .spawn_session(&worktree_req(base.path(), "feature/dup", true))
+        .await;
+    match dup {
+        Err(maestro_e2e::ClientError::Api(maestro_protocol::ClientError::Api { info, .. })) => {
+            assert_eq!(
+                info.code, "worktree_failed",
+                "expected worktree error: {info:?}"
+            );
+        }
+        other => panic!("expected rejection for duplicate branch, got {other:?}"),
+    }
+
+    // Exactly one registration, one directory, still usable.
+    // Count branch records only: the worktree path now contains the branch
+    // name too (`worktrees/feature/dup`), so a substring match over every line
+    // would count the same tree twice.
+    let holders = git_worktree_list(base.path())
+        .iter()
+        .filter(|w| w.as_str() == "branch refs/heads/feature/dup")
+        .count();
+    assert_eq!(holders, 1, "duplicate spawn must not register another tree");
+    assert!(
+        base.path()
+            .join("worktrees")
+            .join("feature")
+            .join("dup")
+            .is_dir(),
+        "original worktree must be untouched"
+    );
+
+    let _origin = throwaway_origin(base.path());
+    client.kill_session(first.id).await.expect("kill");
+}
+
+/// #66/#56: when the client picks a *linked worktree* as base_repo, placement
+/// resolves through `--git-common-dir` to the main checkout, so the new tree
+/// lands at `<main>/worktrees/<branch>` instead of nesting inside another
+/// worktree.
+#[tokio::test(flavor = "multi_thread")]
+async fn spawn_from_linked_worktree_places_in_main_checkout() {
+    let (_daemon, client) = bring_up().await;
+
+    let base = TempDir::new().unwrap();
+    init_repo(base.path());
+    let linked = base.path().join("linked");
+    run_git(
+        &[
+            "worktree",
+            "add",
+            "-q",
+            "-b",
+            "other",
+            &linked.to_string_lossy(),
+        ],
+        base.path(),
+    );
+
+    let s = client
+        .spawn_session(&worktree_req(&linked, "feature/nested", true))
+        .await
+        .expect("spawn from linked worktree");
+
+    let want = base.path().join("worktrees").join("feature").join("nested");
+    assert_eq!(
+        s.cwd, want,
+        "worktree must be placed under the main checkout"
+    );
+    assert!(want.is_dir());
+    assert!(
+        !s.cwd.starts_with(&linked),
+        "worktrees must never nest inside another worktree"
+    );
+
+    let _origin = throwaway_origin(base.path());
+    client.kill_session(s.id).await.expect("kill");
+}
+
+// ---------------------------------------------------------------------------
+// Worktree lifecycle: collisions, retention, reclaim (#88)
+// ---------------------------------------------------------------------------
+
+/// #77/#88: the target path `<repo>/worktrees/<branch>` is occupied by a real
+/// registered worktree the operator made by hand. The daemon sidesteps to the
+/// suffixed directory and never touches the occupant — and both trees keep
+/// working: two registered worktrees, two sessions, each running in its own.
+#[tokio::test(flavor = "multi_thread")]
+async fn occupied_path_gets_suffixed_directory_and_both_worktrees_work() {
+    let (_daemon, client) = bring_up().await;
+
+    let base = TempDir::new().unwrap();
+    init_repo(base.path());
+
+    // An operator-made worktree sits exactly where `feature/collide` would go.
+    // Its branch is a different one, so the requested branch stays creatable.
+    let squatter = base
+        .path()
+        .join("worktrees")
+        .join("feature")
+        .join("collide");
+    run_git(
+        &[
+            "worktree",
+            "add",
+            "-q",
+            "-b",
+            "operator/manual",
+            &squatter.to_string_lossy(),
+        ],
+        base.path(),
+    );
+
+    let s = client
+        .spawn_session(&worktree_req(base.path(), "feature/collide", true))
+        .await
+        .expect("spawn onto occupied path");
+
+    let suffixed = base
+        .path()
+        .join("worktrees")
+        .join("feature")
+        .join("collide-2");
+    assert_eq!(
+        s.cwd, suffixed,
+        "the daemon must take the suffixed directory, not the occupied one"
+    );
+    assert!(suffixed.is_dir(), "suffixed worktree must exist on disk");
+
+    // Both trees are registered, distinct, and the squatter is byte-intact.
+    let registrations = git_worktree_list(base.path());
+    assert!(
+        registrations
+            .iter()
+            .any(|l| l == &format!("worktree {}", squatter.canonicalize().unwrap().display())),
+        "operator's worktree must stay registered: {registrations:?}"
+    );
+    assert!(
+        registrations.iter().any(|l| l.contains("collide-2")),
+        "suffixed worktree must be registered too: {registrations:?}"
+    );
+
+    // Both sessions run inside their own tree at the same time.
+    let sessions = client.list_sessions().await.expect("list");
+    assert!(
+        sessions.iter().any(|x| x.id == s.id && x.cwd == suffixed),
+        "session must keep running in its suffixed tree"
+    );
+
+    let _origin = throwaway_origin(base.path());
+    client.kill_session(s.id).await.expect("kill");
+
+    // Only the daemon-made trees go; the operator's manual one survives.
+    let after = git_worktree_list(base.path());
+    assert!(
+        after
+            .iter()
+            .any(|l| l == &format!("worktree {}", squatter.canonicalize().unwrap().display())),
+        "operator's worktree must outlive the sessions: {after:?}"
+    );
+}
+
+/// #77/#88: the target path holds a plain directory the daemon never made and
+/// git has never heard of. The daemon neither adopts it nor errors — it builds
+/// beside it and leaves every byte of it alone.
+#[tokio::test(flavor = "multi_thread")]
+async fn foreign_directory_is_sidestepped_never_adopted() {
+    let (_daemon, client) = bring_up().await;
+
+    let base = TempDir::new().unwrap();
+    init_repo(base.path());
+
+    let squatter = base
+        .path()
+        .join("worktrees")
+        .join("feature")
+        .join("foreign");
+    std::fs::create_dir_all(&squatter).unwrap();
+    std::fs::write(squatter.join("operator-notes.txt"), b"mine\n").unwrap();
+
+    let s = client
+        .spawn_session(&worktree_req(base.path(), "feature/foreign", true))
+        .await
+        .expect("spawn must sidestep, not adopt or fail");
+
+    let suffixed = base
+        .path()
+        .join("worktrees")
+        .join("feature")
+        .join("foreign-2");
+    assert_eq!(s.cwd, suffixed, "session must run in the suffixed tree");
+    assert_eq!(
+        std::fs::read(squatter.join("operator-notes.txt")).unwrap(),
+        b"mine\n",
+        "the foreign directory must be untouched"
+    );
+    let registrations = git_worktree_list(base.path());
+    let registered_paths: Vec<&str> = registrations
+        .iter()
+        .filter_map(|l| l.strip_prefix("worktree "))
+        .collect();
+    assert!(
+        !registered_paths
+            .iter()
+            .any(|p| *p == squatter.canonicalize().unwrap().display().to_string()),
+        "a plain directory must never be adopted as a worktree: {registered_paths:?}"
+    );
+
+    let _origin = throwaway_origin(base.path());
+    client.kill_session(s.id).await.expect("kill");
+    assert!(squatter.join("operator-notes.txt").exists());
+}
+
+/// #79/#88: killing with uncommitted changes is refused; committing and
+/// pushing that work clears the guard and the very same kill then succeeds
+/// and removes the tree. The session is the handle on the work: while it is
+/// unsaved the session stays, once it is saved the tree goes.
+#[tokio::test(flavor = "multi_thread")]
+async fn guarded_kill_then_commit_and_push_makes_the_same_kill_succeed() {
+    let (_daemon, client) = bring_up().await;
+
+    let base = TempDir::new().unwrap();
+    init_repo(base.path());
+    let _origin = throwaway_origin(base.path());
+
+    let wt = base.path().join("worktrees").join("feature").join("guard");
+    let s = client
+        .spawn_session(&worktree_req(base.path(), "feature/guard", true))
+        .await
+        .expect("spawn");
+    std::fs::write(wt.join("README"), b"work in progress\n").unwrap();
+
+    // Refused: the edit is uncommitted.
+    let err = client
+        .kill_session(s.id)
+        .await
+        .expect_err("kill must refuse");
+    match err {
+        maestro_e2e::ClientError::Api(maestro_protocol::ClientError::Api { info, .. }) => {
+            assert_eq!(info.code, "kill_guarded", "{info:?}");
+            let breakdown = info.unsaved_work.expect("breakdown on the wire");
+            assert_eq!(breakdown.uncommitted_files, 1);
+            assert_eq!(breakdown.unpushed_commits, 0);
+        }
+        other => panic!("expected a kill_guarded refusal, got {other:?}"),
+    }
+    assert!(
+        client
+            .list_sessions()
+            .await
+            .unwrap()
+            .iter()
+            .any(|x| x.id == s.id),
+        "a refused kill keeps the session running"
+    );
+    assert_eq!(
+        std::fs::read(wt.join("README")).unwrap(),
+        b"work in progress\n",
+        "the worktree is untouched by the refusal"
+    );
+
+    // The operator does exactly what the refusal asked for: save and push.
+    commit_all(&wt, "wip");
+    push_all(base.path());
+
+    client.kill_session(s.id).await.expect("kill after saving");
+
+    let deadline = Instant::now() + Duration::from_secs(5);
+    while Instant::now() < deadline {
+        if !wt.exists() {
+            break;
+        }
+        tokio::time::sleep(Duration::from_millis(100)).await;
+    }
+    assert!(
+        !wt.exists(),
+        "a cleared worktree must be removed after kill"
+    );
+    let registrations = git_worktree_list(base.path());
+    assert!(
+        !registrations.iter().any(|l| l.contains("feature/guard")),
+        "removal must deregister the tree: {registrations:?}"
+    );
+}
+
+/// #81/#88: commits that no remote has refuse the kill; `--force` ends the
+/// session anyway but RETAINS the worktree — force never destroys blocked
+/// work, it parks it in the retained store with reason `force-killed`.
+#[tokio::test(flavor = "multi_thread")]
+async fn unpushed_commits_block_kill_and_force_retains_the_tree() {
+    let (_daemon, client) = bring_up().await;
+
+    let base = TempDir::new().unwrap();
+    init_repo(base.path());
+    let _origin = throwaway_origin(base.path());
+
+    let wt = base.path().join("worktrees").join("feature").join("local");
+    let s = client
+        .spawn_session(&worktree_req(base.path(), "feature/local", true))
+        .await
+        .expect("spawn");
+    std::fs::write(wt.join("README"), b"local only\n").unwrap();
+    commit_all(&wt, "not pushed yet");
+
+    // Refused: the commit is on no remote-tracking ref.
+    let err = client
+        .kill_session(s.id)
+        .await
+        .expect_err("kill must refuse");
+    match err {
+        maestro_e2e::ClientError::Api(maestro_protocol::ClientError::Api { info, .. }) => {
+            assert_eq!(info.code, "kill_guarded", "{info:?}");
+            let breakdown = info.unsaved_work.expect("breakdown on the wire");
+            assert_eq!(breakdown.unpushed_commits, 1);
+            assert_eq!(breakdown.uncommitted_files, 0);
+        }
+        other => panic!("expected a kill_guarded refusal, got {other:?}"),
+    }
+
+    // Force overrides the refusal and nothing else: session gone, tree kept.
+    let outcome = client.kill_session_forced(s.id).await.expect("forced kill");
+    let retained = outcome
+        .retained
+        .expect("force must retain the guarded tree");
+    assert_eq!(
+        retained.reason,
+        maestro_protocol::RetainedReason::ForceKilled
+    );
+    assert_eq!(retained.path, wt);
+    assert_eq!(retained.branch, "feature/local");
+    assert_eq!(retained.in_the_way.unpushed_commits, 1);
+
+    assert!(
+        !client
+            .list_sessions()
+            .await
+            .unwrap()
+            .iter()
+            .any(|x| x.id == s.id),
+        "the forced kill ends the session"
+    );
+    assert!(wt.is_dir(), "a force-retained worktree must stay on disk");
+    assert!(
+        git_worktree_list(base.path())
+            .iter()
+            .any(|l| l.contains("feature/local")),
+        "the retained tree stays registered in git"
+    );
+}
+
+/// #82/#88: a session that exits on its own never reaches the kill path, but
+/// its worktree follows the same rule. Dirty → retained with reason
+/// `exited-with-unsaved-work`; pristine → removed, leaving nothing behind.
+#[tokio::test(flavor = "multi_thread")]
+async fn natural_exit_settles_dirty_and_pristine_worktrees_differently() {
+    let (_daemon, client) = bring_up().await;
+
+    // Two repos so the two cases cannot see each other's state.
+    let dirty_repo = TempDir::new().unwrap();
+    init_repo(dirty_repo.path());
+    let _origin = throwaway_origin(dirty_repo.path());
+    let pristine_repo = TempDir::new().unwrap();
+    init_repo(pristine_repo.path());
+    let _origin_pristine = throwaway_origin(pristine_repo.path());
+
+    let dirty_wt = dirty_repo
+        .path()
+        .join("worktrees")
+        .join("feature")
+        .join("messy");
+    let pristine_wt = pristine_repo
+        .path()
+        .join("worktrees")
+        .join("feature")
+        .join("tidy");
+
+    let _dirty = client
+        .spawn_session(&CreateSessionRequest {
+            cwd: dirty_repo.path().to_path_buf(),
+            command: "sh -c 'echo unsaved > scratch.txt'".into(),
+            env: HashMap::new(),
+            metadata: HashMap::new(),
+            worktree: Some(worktree_spec(dirty_repo.path(), "feature/messy", true)),
+        })
+        .await
+        .expect("spawn dirty");
+    let _pristine = client
+        .spawn_session(&create_req_cmd(
+            pristine_repo.path(),
+            "true",
+            "feature/tidy",
+        ))
+        .await
+        .expect("spawn pristine");
+
+    assert!(dirty_wt.is_dir() && pristine_wt.is_dir());
+
+    // The watcher reaps dead tmux sessions every couple of ticks and settles
+    // each worktree accordingly. Poll for both outcomes.
+    wait_for_async(
+        "dirty exit retains its worktree",
+        Duration::from_secs(20),
+        || {
+            let client = client.clone();
+            let path = dirty_wt.clone();
+            async move {
+                client
+                    .list_worktrees()
+                    .await
+                    .ok()
+                    .map(|wts| {
+                        wts.iter().any(|w| {
+                            w.path == path
+                                && w.reason
+                                    == maestro_protocol::RetainedReason::ExitedWithUnsavedWork
+                        })
+                    })
+                    .unwrap_or(false)
+            }
+        },
+    )
+    .await;
+    wait_for_async(
+        "pristine exit removes its worktree entirely",
+        Duration::from_secs(20),
+        || {
+            let client = client.clone();
+            let repo = pristine_repo.path().to_path_buf();
+            let path = pristine_wt.clone();
+            async move {
+                if path.exists() {
+                    return false;
+                }
+                let listed = client.list_worktrees().await.ok();
+                let listed_clear = listed
+                    .map(|wts| !wts.iter().any(|w| w.path == path))
+                    .unwrap_or(false);
+                let registered = git_worktree_list(&repo);
+                !registered.iter().any(|l| l.contains("feature/tidy")) && listed_clear
+            }
+        },
+    )
+    .await;
+
+    // The dirty tree is still fully there, file included.
+    assert!(dirty_wt.is_dir());
+    assert_eq!(
+        std::fs::read(dirty_wt.join("scratch.txt")).unwrap(),
+        b"unsaved\n"
+    );
+}
+
+fn create_req_cmd(cwd: &std::path::Path, command: &str, branch: &str) -> CreateSessionRequest {
+    CreateSessionRequest {
+        cwd: cwd.to_path_buf(),
+        command: command.into(),
+        env: HashMap::new(),
+        metadata: HashMap::new(),
+        worktree: Some(worktree_spec(cwd, branch, true)),
+    }
+}
+
+/// #80/#88: `GET /api/worktrees` lists what the daemon is holding, with the
+/// reason and a live in-the-way breakdown; reclaim removes the directory and
+/// the store entry but NEVER the branch — its commits outlive the reclaim.
+#[tokio::test(flavor = "multi_thread")]
+async fn worktrees_endpoint_lists_reasons_and_reclaim_keeps_the_branch() {
+    let (_daemon, client) = bring_up().await;
+
+    let base = TempDir::new().unwrap();
+    init_repo(base.path());
+    let _origin = throwaway_origin(base.path());
+
+    let wt = base.path().join("worktrees").join("feature").join("parked");
+    let s = client
+        .spawn_session(&worktree_req(base.path(), "feature/parked", true))
+        .await
+        .expect("spawn");
+    std::fs::write(wt.join("README"), b"worth keeping\n").unwrap();
+    commit_all(&wt, "worth keeping");
+    let sha = branch_sha(&wt, "feature/parked");
+
+    let outcome = client.kill_session_forced(s.id).await.expect("force kill");
+    assert!(outcome.retained.is_some());
+
+    let listed = client.list_worktrees().await.expect("list worktrees");
+    assert_eq!(listed.len(), 1, "exactly one retained entry: {listed:?}");
+    let entry = &listed[0];
+    assert_eq!(entry.path, wt);
+    assert_eq!(entry.branch, "feature/parked");
+    assert_eq!(entry.reason, maestro_protocol::RetainedReason::ForceKilled);
+    assert_eq!(entry.in_the_way.unpushed_commits, 1);
+
+    client.reclaim_worktree(entry.id).await.expect("reclaim");
+    assert!(!wt.exists(), "reclaim removes the directory");
+    assert!(
+        client.list_worktrees().await.unwrap().is_empty(),
+        "reclaim drops the store entry"
+    );
+
+    // The whole point of reclaim: the branch and its commits survive.
+    assert_eq!(
+        branch_sha(base.path(), "feature/parked"),
+        sha,
+        "the branch must keep pointing at the same commit after reclaim"
+    );
+}
+
+/// The retained store is state-dir backed (#80): a daemon restart must not
+/// orphan the trees it is holding — they are still on disk with entries
+/// pointing at them, and still reclaimable afterwards.
+#[tokio::test(flavor = "multi_thread")]
+async fn retained_store_survives_a_daemon_restart() {
+    let (mut daemon, client) = bring_up().await;
+
+    let base = TempDir::new().unwrap();
+    init_repo(base.path());
+    let _origin = throwaway_origin(base.path());
+
+    let wt = base
+        .path()
+        .join("worktrees")
+        .join("feature")
+        .join("durable");
+    let s = client
+        .spawn_session(&worktree_req(base.path(), "feature/durable", true))
+        .await
+        .expect("spawn");
+    std::fs::write(wt.join("README"), b"survives restarts\n").unwrap();
+    commit_all(&wt, "survives restarts");
+    client.kill_session_forced(s.id).await.expect("force kill");
+
+    daemon.restart().await;
+
+    let listed = client.list_worktrees().await.expect("list after restart");
+    assert_eq!(listed.len(), 1, "store must survive restart: {listed:?}");
+    assert_eq!(listed[0].path, wt);
+    assert_eq!(
+        listed[0].reason,
+        maestro_protocol::RetainedReason::ForceKilled
+    );
+    assert!(wt.is_dir(), "the tree itself must survive the restart too");
+
+    client
+        .reclaim_worktree(listed[0].id)
+        .await
+        .expect("reclaim");
+    assert!(!wt.exists());
+}
+
+// ---------------------------------------------------------------------------
+// GET /api/projects + /api/branches (#54/#55/#66)
+// ---------------------------------------------------------------------------
+
+/// #66: two repos under a configured `[spawn].project_roots` root are both
+/// discovered by `GET /api/projects`; git activity gives every repo a
+/// `last_activity`, and spawning inside one merges its command into the
+/// project entry via spawn history.
+#[tokio::test(flavor = "multi_thread")]
+async fn projects_endpoint_discovers_roots_and_merges_activity() {
+    let root = TempDir::new().unwrap();
+    let alpha = make_repo(root.path(), "alpha");
+    make_repo(root.path(), "beta");
+
+    let daemon = Daemon::spawn_with_config(&format!(
+        "[spawn]\nproject_roots = [\"{}\"]\nproject_scan_depth = 2\n",
+        root.path().display()
+    ))
+    .await;
+    let client = TestClient::new(&daemon.http_base());
+
+    let projects = client.list_projects().await.expect("list projects");
+    let names: Vec<&str> = projects.iter().map(|p| p.name.as_str()).collect();
+    assert!(
+        names.contains(&"alpha") && names.contains(&"beta"),
+        "both repos must be discovered, got: {names:?}"
+    );
+
+    let find = |name: &str| {
+        projects
+            .iter()
+            .find(|p| p.name == name)
+            .cloned()
+            .expect("project present")
+    };
+    // Both have commits, so git activity alone populates last_activity…
+    assert!(
+        find("alpha").last_activity.is_some(),
+        "git activity must surface"
+    );
+    assert!(
+        find("beta").last_activity.is_some(),
+        "git activity must surface"
+    );
+    // …and neither has been spawned into yet.
+    assert_eq!(find("alpha").last_command, None);
+    assert_eq!(find("beta").last_command, None);
+
+    // Spawning inside alpha writes durable history; /api/projects folds it in.
+    let s = client
+        .spawn_session(&create_req(&alpha, "sleep 30"))
+        .await
+        .expect("spawn in alpha");
+
+    wait_for_async(
+        "alpha's project entry reflects spawn history",
+        Duration::from_secs(5),
+        || {
+            let client = client.clone();
+            async move {
+                client
+                    .list_projects()
+                    .await
+                    .ok()
+                    .map(|ps| {
+                        ps.iter()
+                            .find(|p| p.name == "alpha")
+                            .map(|p| p.last_command.as_deref() == Some("sleep 30"))
+                            .unwrap_or(false)
+                    })
+                    .unwrap_or(false)
+            }
+        },
+    )
+    .await;
+
+    // beta was never spawned into: no command recorded there.
+    let beta_after = client
+        .list_projects()
+        .await
+        .expect("list after spawn")
+        .into_iter()
+        .find(|p| p.name == "beta")
+        .unwrap();
+    assert_eq!(beta_after.last_command, None);
+
+    client.kill_session(s.id).await.expect("kill");
+}
+
+/// #66: `GET /api/branches` lists every local branch, flags the main
+/// checkout's HEAD with `is_head`, and reports which linked worktree holds an
+/// occupied branch.
+#[tokio::test(flavor = "multi_thread")]
+async fn branches_endpoint_lists_branches_and_flags_occupied() {
+    let (_daemon, client) = bring_up().await;
+
+    let base = TempDir::new().unwrap();
+    init_repo(base.path());
+    run_git(&["branch", "feature/taken"], base.path());
+    run_git(&["branch", "feature/free"], base.path());
+    let holder = base.path().join("holder-wt");
+    run_git(
+        &[
+            "worktree",
+            "add",
+            "-q",
+            &holder.to_string_lossy(),
+            "feature/taken",
+        ],
+        base.path(),
+    );
+
+    let branches = client
+        .list_branches(&base.path().to_string_lossy())
+        .await
+        .expect("list branches");
+    let by_name = |name: &str| {
+        branches
+            .iter()
+            .find(|b| b.name == name)
+            .cloned()
+            .unwrap_or_else(|| panic!("branch {name} missing from {branches:?}"))
+    };
+
+    let main = by_name("main");
+    assert!(main.is_head, "main is the main checkout's HEAD");
+    assert_eq!(main.worktree, None);
+
+    let taken = by_name("feature/taken");
+    assert!(!taken.is_head);
+    assert_eq!(
+        taken.worktree.as_deref(),
+        Some(holder.canonicalize().unwrap().as_path()),
+        "occupied branch must report its holding worktree"
+    );
+
+    let free = by_name("feature/free");
+    assert!(!free.is_head);
+    assert_eq!(free.worktree, None, "unoccupied branch must be spawnable");
+}
+
 #[tokio::test(flavor = "multi_thread")]
 async fn daemon_restart_recovers_session() {
     let (mut daemon, client) = bring_up().await;
@@ -428,6 +1214,15 @@ fn init_repo(dir: &std::path::Path) {
     run_git(&["commit", "-q", "-m", "initial"], dir);
 }
 
+/// Real git repo at `<root>/<name>`, canonicalized (the scanner canonicalizes
+/// discovered paths too, so comparisons must agree on the real path).
+fn make_repo(root: &std::path::Path, name: &str) -> std::path::PathBuf {
+    let dir = root.join(name);
+    std::fs::create_dir_all(&dir).unwrap();
+    init_repo(&dir);
+    dir.canonicalize().unwrap()
+}
+
 fn run_git(args: &[&str], cwd: &std::path::Path) {
     let out = Command::new("git")
         .arg("-C")
@@ -455,6 +1250,51 @@ fn git_worktree_list(dir: &std::path::Path) -> Vec<String> {
         .collect()
 }
 
+/// Bare remote registered as `origin` on `repo`, seeded with every current
+/// branch, so existing commits are reachable from remote-tracking refs.
+/// Without one the kill guard (#79) reads every commit as unpushed, and any
+/// worktree session refuses to die. The caller must keep the `TempDir` alive
+/// while the remote is still needed; later pushes go through [`push_all`].
+fn throwaway_origin(repo: &std::path::Path) -> TempDir {
+    let origin = tempfile::TempDir::new().unwrap();
+    run_git(
+        &["init", "-q", "--bare", origin.path().to_str().unwrap()],
+        repo,
+    );
+    let _ = Command::new("git")
+        .arg("-C")
+        .arg(repo)
+        .args(["remote", "add", "origin", origin.path().to_str().unwrap()])
+        .output()
+        .expect("git remote add");
+    push_all(repo);
+    origin
+}
+
+fn push_all(repo: &std::path::Path) {
+    run_git(&["push", "-q", "--all", "origin"], repo);
+}
+
+fn commit_all(dir: &std::path::Path, message: &str) {
+    run_git(&["add", "-A"], dir);
+    run_git(&["commit", "-q", "-m", message], dir);
+}
+
+fn branch_sha(repo: &std::path::Path, branch: &str) -> String {
+    let out = Command::new("git")
+        .arg("-C")
+        .arg(repo)
+        .args(["rev-parse", "--verify", &format!("refs/heads/{branch}")])
+        .output()
+        .expect("git rev-parse");
+    assert!(
+        out.status.success(),
+        "branch {branch} missing: {}",
+        String::from_utf8_lossy(&out.stderr)
+    );
+    String::from_utf8_lossy(&out.stdout).trim().to_string()
+}
+
 #[tokio::test(flavor = "multi_thread")]
 async fn daemon_events_ws_streams_snapshot_then_session_added() {
     // NAP-248: subscribe to the daemon's WS /api/events, expect an initial

crates/maestro-protocol/src/client.rs

@@ -15,8 +15,8 @@ use uuid::Uuid;
 
 use crate::routes::{self, UrlError};
 use crate::{
-    ApiError, CreateSessionRequest, DaemonInfo, DirListing, ErrorInfo, GitRoot, Project,
-    RecentDirs, Session,
+    ApiError, BranchInfo, CreateSessionRequest, DaemonInfo, DirListing, ErrorInfo, GitRoot,
+    KillOutcome, Project, RecentDirs, RetainedWorktree, Session,
 };
 
 /// Time budget for establishing a TCP connection to the daemon.
@@ -114,12 +114,24 @@ impl DaemonClient {
         self.post(routes::SESSIONS, req).await
     }
 
-    pub async fn kill_session(&self, id: Uuid) -> Result<(), ClientError> {
+    /// Kill a session. With `force`, the daemon overrides the kill refusal
+    /// (#79) and retains the worktree instead of removing it (#81); the
+    /// outcome then names what was kept and where.
+    pub async fn kill_session(&self, id: Uuid, force: bool) -> Result<KillOutcome, ClientError> {
+        let query: &[(&str, &str)] = if force {
+            &[(routes::FORCE_QUERY, "true")]
+        } else {
+            &[]
+        };
         let resp = self
-            .send(Method::DELETE, &routes::session(id), &[], None::<&()>)
+            .send(Method::DELETE, &routes::session(id), query, None::<&()>)
             .await?;
-        check(resp).await?;
-        Ok(())
+        let resp = check(resp).await?;
+        // An unforced kill keeps its historical `204 No Content`.
+        if resp.status() == reqwest::StatusCode::NO_CONTENT {
+            return Ok(KillOutcome { retained: None });
+        }
+        json(resp).await
     }
 
     pub async fn daemon_info(&self) -> Result<DaemonInfo, ClientError> {
@@ -143,6 +155,28 @@ impl DaemonClient {
         self.get(routes::PROJECTS, &[]).await
     }
 
+    pub async fn list_branches(&self, path: &str) -> Result<Vec<BranchInfo>, ClientError> {
+        self.get(routes::BRANCHES, &[(routes::PATH_QUERY, path)])
+            .await
+    }
+
+    /// `GET /api/worktrees` (#80): every retained worktree with its in-the-way
+    /// breakdown as of this read.
+    pub async fn list_worktrees(&self) -> Result<Vec<RetainedWorktree>, ClientError> {
+        self.get(routes::WORKTREES, &[]).await
+    }
+
+    /// `DELETE /api/worktrees/:id` (#86): reclaim one retained worktree. The
+    /// daemon removes the directory and drops the store entry; the branch is
+    /// never deleted.
+    pub async fn reclaim_worktree(&self, id: Uuid) -> Result<(), ClientError> {
+        let resp = self
+            .send(Method::DELETE, &routes::worktree(id), &[], None::<&()>)
+            .await?;
+        check(resp).await?;
+        Ok(())
+    }
+
     // -- plumbing -----------------------------------------------------------
 
     async fn get<T: DeserializeOwned>(

crates/maestro-protocol/src/lib.rs

@@ -53,6 +53,14 @@ pub struct Session {
     pub env: HashMap<String, String>,
     #[serde(default)]
     pub metadata: HashMap<String, Value>,
+    /// The worktree this session owns, when it was spawned with one.
+    ///
+    /// Persisted rather than kept in memory only: after a daemon restart the
+    /// recovered session must still know what to clean up, and with
+    /// deterministic worktree paths a forgotten association leaves a directory
+    /// that blocks that branch from ever being spawned again (#54 review).
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub worktree: Option<SessionWorktree>,
     pub status: SessionStatus,
     pub created_at: DateTime<Utc>,
     /// Current foreground command in the session's pane (e.g. `claude`,
@@ -79,6 +87,13 @@ pub struct Session {
     /// from daemons that predate the field.
     #[serde(default)]
     pub current_cwd: Option<PathBuf>,
+    /// Whether the session's worktree currently holds anything that would
+    /// block an unforced kill (#83), summarised by [`InTheWay`]'s `Display`.
+    /// Refreshed by the daemon's watcher; `None` for sessions without a
+    /// worktree and until the first probe. Defaults on the wire so payloads
+    /// from daemons that predate the field stay forward-compatible.
+    #[serde(default)]
+    pub blocked_work: Option<InTheWay>,
 }
 
 /// Default for [`Session::last_activity_at`] when an older payload omits it.
@@ -111,11 +126,6 @@ pub enum ActivityState {
 pub struct WorktreeSpec {
     pub base_repo: PathBuf,
     pub branch: String,
-    /// Kept on the wire for CLI compatibility (#56) but no longer a
-    /// user-facing choice: the daemon always cleans up on kill, guarded
-    /// against unsaved work. Defaults to `true`.
-    #[serde(default = "default_true")]
-    pub cleanup_on_kill: bool,
     /// When false, `branch` must already exist and is checked out as-is
     /// (#56); when true (the default, and what every payload meant before
     /// the field existed) the daemon creates it with `worktree add -b`.
@@ -127,6 +137,108 @@ fn default_true() -> bool {
     true
 }
 
+/// The worktree a running session owns, carried on [`Session`] so it survives
+/// a daemon restart.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub struct SessionWorktree {
+    pub path: PathBuf,
+    pub base_repo: PathBuf,
+}
+
+/// Why a retained worktree outlived its session (#80). Same values the
+/// daemon's retained store persists; new variants are additive but clients
+/// should render unknown reasons generically.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+#[serde(rename_all = "kebab-case")]
+pub enum RetainedReason {
+    /// The session was killed with `--force` while its worktree held unsaved
+    /// work.
+    ForceKilled,
+    /// The session ended by itself and its worktree held unsaved work.
+    ExitedWithUnsavedWork,
+}
+
+/// What a kill refusal would report about a worktree right now (#80) — the
+/// same breakdown that blocks an unforced kill, recomputed on every read of
+/// [`RetainedWorktree`] so it reflects the tree now rather than when it was
+/// retained.
+#[derive(Debug, Clone, Copy, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub struct InTheWay {
+    /// Tracked files with uncommitted modifications.
+    #[serde(default)]
+    pub uncommitted_files: usize,
+    /// Untracked files that are not ignored (ignored files never block).
+    #[serde(default)]
+    pub untracked_files: usize,
+    /// Commits on the branch reachable from no remote-tracking ref.
+    #[serde(default)]
+    pub unpushed_commits: usize,
+}
+
+impl InTheWay {
+    /// Nothing blocks any more — the work has since been committed and pushed.
+    pub fn is_clear(&self) -> bool {
+        *self == Self::default()
+    }
+}
+
+/// One entry of `GET /api/worktrees` (#80): a retained worktree with its
+/// in-the-way state as of this read. Reclaiming it via
+/// `DELETE /api/worktrees/:id` removes the directory but **never** the branch.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub struct RetainedWorktree {
+    pub id: Uuid,
+    pub path: PathBuf,
+    pub base_repo: PathBuf,
+    pub branch: String,
+    pub reason: RetainedReason,
+    pub retained_at: DateTime<Utc>,
+    #[serde(default)]
+    pub in_the_way: InTheWay,
+}
+
+/// Body of a successful forced `DELETE /api/sessions/:id?force=true` (#81).
+/// A forced kill ends the session and retains its worktree instead of
+/// removing it; this names what was kept, where, and why, so a client can say
+/// where the work went rather than leaving the operator to wonder.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub struct KillOutcome {
+    /// Set when the worktree was retained with reason `force-killed`; `None`
+    /// when there was nothing to retain — no worktree at all, or one whose
+    /// guard was clear, which a forced kill removes as usual.
+    #[serde(default)]
+    pub retained: Option<RetainedWorktree>,
+}
+
+impl std::fmt::Display for InTheWay {
+    /// "3 uncommitted files, 2 unpushed commits" — zero parts are omitted;
+    /// all-zero renders "no unsaved work". This is the phrasing every client
+    /// uses for both the kill refusal and the retained list, so the two
+    /// cannot describe the same tree differently.
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let parts = [
+            (self.uncommitted_files, "uncommitted file"),
+            (self.untracked_files, "untracked file"),
+            (self.unpushed_commits, "unpushed commit"),
+        ];
+        let said: Vec<String> = parts
+            .into_iter()
+            .filter(|(n, _)| *n > 0)
+            .map(|(n, unit)| {
+                if n == 1 {
+                    format!("1 {unit}")
+                } else {
+                    format!("{n} {unit}s")
+                }
+            })
+            .collect();
+        if said.is_empty() {
+            return write!(f, "no unsaved work");
+        }
+        write!(f, "{}", said.join(", "))
+    }
+}
+
 /// HTTP `POST /api/sessions` body.
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 pub struct CreateSessionRequest {
@@ -232,6 +344,10 @@ pub struct BranchInfo {
 pub struct ErrorInfo {
     pub code: String,
     pub message: String,
+    /// Set only by the kill guard (#79): the unsaved work that blocked
+    /// `DELETE /api/sessions/:id`, so a client can render counts directly.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub unsaved_work: Option<InTheWay>,
 }
 
 /// The envelope every `/api/*` failure is wrapped in: `{"error": {…}}`.
@@ -252,6 +368,7 @@ impl ApiError {
             error: ErrorInfo {
                 code: code.into(),
                 message: message.into(),
+                unsaved_work: None,
             },
         }
     }
@@ -410,6 +527,7 @@ mod tests {
             command: "claude".into(),
             env: HashMap::from([("FOO".into(), "bar".into())]),
             metadata: HashMap::from([("name".into(), Value::String("maestro-impl".into()))]),
+            worktree: None,
             status: SessionStatus::Running,
             created_at: DateTime::parse_from_rfc3339("2026-05-24T12:00:00Z")
                 .unwrap()
@@ -420,6 +538,7 @@ mod tests {
                 .unwrap()
                 .with_timezone(&Utc),
             current_cwd: Some(PathBuf::from("/home/naps62/projects/maestro/crates")),
+            blocked_work: None,
         }
     }
 
@@ -439,6 +558,34 @@ mod tests {
         assert_eq!(s.activity, ActivityState::Idle);
         assert_eq!(s.last_activity_at, epoch());
         assert!(s.current_cwd.is_none());
+        assert!(s.blocked_work.is_none());
+    }
+
+    #[test]
+    fn blocked_work_defaults_to_none_on_legacy_payload() {
+        // A pre-#83 daemon omits the indicator; it must deserialize to `None`
+        // rather than failing, and a present value round-trips.
+        let json = serde_json::json!({
+            "id": Uuid::from_u128(1),
+            "cwd": "/tmp",
+            "command": "bash",
+            "status": "Running",
+            "created_at": "2026-05-24T12:00:00Z"
+        });
+        let s: Session = serde_json::from_value(json).unwrap();
+        assert_eq!(s.blocked_work, None);
+
+        let mut with_blocker = sample_session();
+        with_blocker.blocked_work = Some(InTheWay {
+            uncommitted_files: 3,
+            ..InTheWay::default()
+        });
+        assert_eq!(
+            with_blocker.clone().blocked_work,
+            serde_json::from_value::<Session>(serde_json::to_value(&with_blocker).unwrap())
+                .unwrap()
+                .blocked_work
+        );
     }
 
     #[test]
@@ -478,7 +625,6 @@ mod tests {
             worktree: Some(WorktreeSpec {
                 base_repo: PathBuf::from("/home/naps62/projects/maestro"),
                 branch: "feat/foo".into(),
-                cleanup_on_kill: true,
                 create_branch: true,
             }),
         };
@@ -508,7 +654,6 @@ mod tests {
         });
         let spec: WorktreeSpec = serde_json::from_value(json).unwrap();
         assert!(spec.create_branch);
-        assert!(spec.cleanup_on_kill);
     }
 
     #[test]
@@ -516,12 +661,81 @@ mod tests {
         let spec = WorktreeSpec {
             base_repo: PathBuf::from("/work"),
             branch: "feat/foo".into(),
-            cleanup_on_kill: true,
             create_branch: false,
         };
         assert_eq!(spec, round_trip(&spec));
     }
 
+    fn sample_retained_worktree() -> RetainedWorktree {
+        RetainedWorktree {
+            id: Uuid::from_u128(0x0123_4567_89ab_cdef_0123_4567_89ab_cdef),
+            path: PathBuf::from("/work/maestro/worktrees/feat/login"),
+            base_repo: PathBuf::from("/work/maestro"),
+            branch: "feat/login".into(),
+            reason: RetainedReason::ForceKilled,
+            retained_at: DateTime::parse_from_rfc3339("2026-08-24T10:00:00Z")
+                .unwrap()
+                .with_timezone(&Utc),
+            in_the_way: InTheWay {
+                uncommitted_files: 2,
+                untracked_files: 1,
+                unpushed_commits: 3,
+            },
+        }
+    }
+
+    #[test]
+    fn retained_worktree_round_trips() {
+        let wt = sample_retained_worktree();
+        assert_eq!(wt, round_trip(&wt));
+    }
+
+    /// A payload from a daemon predating `in_the_way` still decodes; the
+    /// breakdown defaults to "nothing in the way".
+    #[test]
+    fn retained_worktree_defaults_in_the_way_on_legacy_payload() {
+        let legacy = serde_json::json!({
+            "id": Uuid::from_u128(1),
+            "path": "/w/t",
+            "base_repo": "/w",
+            "branch": "feat/login",
+            "reason": "force-killed",
+            "retained_at": "2026-08-24T10:00:00Z",
+        });
+        let wt: RetainedWorktree = serde_json::from_value(legacy).unwrap();
+        assert_eq!(wt.reason, RetainedReason::ForceKilled);
+        assert_eq!(wt.in_the_way, InTheWay::default());
+        assert!(wt.in_the_way.is_clear());
+    }
+
+    #[test]
+    fn retained_reason_serializes_kebab_case() {
+        assert_eq!(
+            serde_json::to_value(RetainedReason::ForceKilled).unwrap(),
+            serde_json::json!("force-killed")
+        );
+        assert_eq!(
+            serde_json::to_value(RetainedReason::ExitedWithUnsavedWork).unwrap(),
+            serde_json::json!("exited-with-unsaved-work")
+        );
+    }
+
+    #[test]
+    fn kill_outcome_round_trips_a_retained_worktree() {
+        let outcome = KillOutcome {
+            retained: Some(sample_retained_worktree()),
+        };
+        assert_eq!(outcome, round_trip(&outcome));
+    }
+
+    /// A kill with nothing to retain — no worktree, or a clean one removed as
+    /// usual — decodes from an absent field.
+    #[test]
+    fn kill_outcome_defaults_to_nothing_retained() {
+        let outcome: KillOutcome = serde_json::from_value(serde_json::json!({})).unwrap();
+        assert_eq!(outcome.retained, None);
+    }
+
     #[test]
     fn catalog_event_round_trips_and_tags() {
         let session = sample_session();
@@ -561,6 +775,7 @@ mod tests {
             ClientControl::Error(ErrorInfo {
                 code: "bad_frame".into(),
                 message: "decode failed".into(),
+                unsaved_work: None,
             }),
             resize,
         ] {

crates/maestro-protocol/src/routes.rs

@@ -26,6 +26,9 @@ pub const BRANCHES: &str = "/api/branches";
 /// `GET` a batch of generated session handles (#53). Takes a `count` query
 /// param (default 1, capped at [`maestro_names`]' batch cap).
 pub const NAMES: &str = "/api/names";
+/// `GET` retained worktrees (#80): what the store holds, with the in-the-way
+/// breakdown recomputed on read.
+pub const WORKTREES: &str = "/api/worktrees";
 /// `WS` catalog snapshot + session deltas.
 pub const EVENTS: &str = "/api/events";
 
@@ -35,11 +38,20 @@ pub const PATH_QUERY: &str = "path";
 /// Name of the query parameter [`NAMES`] takes.
 pub const COUNT_QUERY: &str = "count";
 
+/// Name of the boolean query parameter `DELETE /api/sessions/:id` takes (#81).
+/// `force=true` overrides the kill refusal and retains the worktree.
+pub const FORCE_QUERY: &str = "force";
+
 /// `DELETE /api/sessions/:id`.
 pub fn session(id: Uuid) -> String {
     format!("{SESSIONS}/{id}")
 }
 
+/// `DELETE /api/worktrees/:id` — reclaim one retained worktree (#80).
+pub fn worktree(id: Uuid) -> String {
+    format!("{WORKTREES}/{id}")
+}
+
 /// `WS /api/attach/:id` — raw PTY bytes.
 pub fn attach(id: Uuid) -> String {
     format!("{API_PREFIX}/attach/{id}")
@@ -50,6 +62,7 @@ pub fn attach(id: Uuid) -> String {
 pub mod patterns {
     pub const SESSION: &str = "/api/sessions/:id";
     pub const ATTACH: &str = "/api/attach/:id";
+    pub const WORKTREE: &str = "/api/worktrees/:id";
 }
 
 /// A daemon base URL that could not be turned into a WebSocket base.
@@ -160,6 +173,10 @@ mod tests {
             attach(id()),
             "/api/attach/6f1a7c0e-0f5e-4a2b-9a3d-6b1c2d3e4f50"
         );
+        assert_eq!(
+            worktree(id()),
+            "/api/worktrees/6f1a7c0e-0f5e-4a2b-9a3d-6b1c2d3e4f50"
+        );
         assert_eq!(
             attach_url("https://laptop.lan:7070", id()).unwrap(),
             "wss://laptop.lan:7070/api/attach/6f1a7c0e-0f5e-4a2b-9a3d-6b1c2d3e4f50"
@@ -178,6 +195,10 @@ mod tests {
             patterns::ATTACH.trim_end_matches(":id"),
             attach(id()).trim_end_matches(&id().to_string())
         );
+        assert_eq!(
+            patterns::WORKTREE.trim_end_matches(":id"),
+            worktree(id()).trim_end_matches(&id().to_string())
+        );
     }
 
     #[test]
@@ -191,6 +212,7 @@ mod tests {
             GITROOT,
             BRANCHES,
             NAMES,
+            WORKTREES,
             EVENTS,
         ] {
             assert!(path.starts_with(API_PREFIX), "{path} escapes {API_PREFIX}");

crates/maestro-testing/src/lib.rs

@@ -36,12 +36,14 @@ pub fn session(id: Uuid, cwd: &str, command: &str) -> Session {
         command: command.into(),
         env: HashMap::new(),
         metadata: HashMap::new(),
+        worktree: None,
         status: SessionStatus::Running,
         created_at: Utc::now(),
         foreground: None,
         activity: Default::default(),
         last_activity_at: Utc::now(),
         current_cwd: None,
+        blocked_work: None,
     }
 }
 

crates/maestro-tui/src/action.rs

@@ -39,7 +39,12 @@ pub enum Action {
     AttachHighlighted,
     ToggleAttachHighlighted,
     NewDraftPane,
+    /// Fast-forward spawn (#67): spawn immediately with every default
+    /// resolved; unresolvable defaults open a pre-filled draft instead.
+    FastForwardSpawn,
     KillHighlighted,
+    /// Open the retained-worktrees view (#85).
+    ShowWorktrees,
 
     // Tabs
     NewTab,
@@ -79,7 +84,9 @@ impl Action {
             "AttachHighlighted" => return Ok(Action::AttachHighlighted),
             "ToggleAttachHighlighted" => return Ok(Action::ToggleAttachHighlighted),
             "NewDraftPane" => return Ok(Action::NewDraftPane),
+            "FastForwardSpawn" => return Ok(Action::FastForwardSpawn),
             "KillHighlighted" => return Ok(Action::KillHighlighted),
+            "ShowWorktrees" => return Ok(Action::ShowWorktrees),
             "NewTab" => return Ok(Action::NewTab),
             "CloseTab" => return Ok(Action::CloseTab),
             "NextTab" => return Ok(Action::NextTab),
@@ -197,6 +204,16 @@ mod tests {
         assert_eq!(err, ActionParseError::Malformed("GotoTab(3".into()));
     }
 
+    /// The fast-forward pair sits next to the draft-pane key (#67).
+    #[test]
+    fn fast_forward_spawn_round_trips() {
+        assert_eq!(
+            Action::parse("FastForwardSpawn").unwrap(),
+            Action::FastForwardSpawn
+        );
+        assert_eq!(Action::FastForwardSpawn.to_string(), "FastForwardSpawn");
+    }
+
     #[test]
     fn display_round_trips() {
         for a in [

crates/maestro-tui/src/catalog.rs

@@ -188,12 +188,14 @@ mod tests {
             cwd: std::path::PathBuf::from("/tmp"),
             env: Default::default(),
             metadata: Default::default(),
+            worktree: None,
             status: SessionStatus::Running,
             created_at: Utc::now(),
             foreground: None,
             activity: Default::default(),
             last_activity_at: chrono::Utc::now(),
             current_cwd: None,
+            blocked_work: None,
         }
     }
 

crates/maestro-tui/src/config.rs

@@ -46,7 +46,11 @@ const DEFAULT_NORMAL: &[(&str, &str)] = &[
     // Catalog actions
     ("enter", "AttachHighlighted"),
     ("s", "NewDraftPane"),
+    // Fast-forward spawn (#67): the draft-pane key's neighbour does the same
+    // thing with every default resolved and no form.
+    ("S", "FastForwardSpawn"),
     ("x", "KillHighlighted"),
+    ("w", "ShowWorktrees"),
     // Tabs
     ("ctrl-t", "NewTab"),
     ("g t", "NextTab"),
@@ -159,6 +163,14 @@ mod tests {
             cfg.keymap.resolve(Mode::Normal, "s"),
             Some(Action::NewDraftPane),
         );
+        assert_eq!(
+            cfg.keymap.resolve(Mode::Normal, "S"),
+            Some(Action::FastForwardSpawn),
+        );
+        assert_eq!(
+            cfg.keymap.resolve(Mode::Normal, "w"),
+            Some(Action::ShowWorktrees),
+        );
     }
 
     #[test]
@@ -226,6 +238,26 @@ mod tests {
         assert!(s.contains("ctrl-glorb"), "diagnostic: {s}");
     }
 
+    /// Regression for #70: the previous canonical form of a real Shift+S
+    /// keypress was `"shift-S"`, which the default `"S"` binding never
+    /// matched. Drive the actual crossterm event, not the binding string,
+    /// so the dead-key bug can't come back unnoticed.
+    #[test]
+    fn real_shift_s_keypress_resolves_to_fast_forward_spawn() {
+        use crossterm::event::{Event as CtEvent, KeyCode, KeyEvent, KeyModifiers};
+
+        use crate::input::{canonicalise, Region};
+
+        let cfg = TuiConfig::load(&TuiSection::default()).unwrap();
+        let ev = CtEvent::Key(KeyEvent::new(KeyCode::Char('S'), KeyModifiers::SHIFT));
+        let key = canonicalise(&ev, |_, _| Region::Unknown).expect("key event canonicalises");
+
+        assert_eq!(
+            cfg.keymap.resolve(Mode::Normal, &key.canonical()),
+            Some(Action::FastForwardSpawn),
+        );
+    }
+
     #[test]
     fn custom_chord_timeout_is_applied() {
         let mut section = TuiSection::default();

crates/maestro-tui/src/fast_forward.rs

@@ -0,0 +1,282 @@
+//! Fast-forward spawn (#67): one keystroke, every default resolved, no form.
+//!
+//! The defaults mirror what a draft pane would settle on after the operator
+//! picked the most recent project and kept their hands off everything else:
+//! its last command (or the first non-custom preset), a freshly generated
+//! name, and a worktree with a branch named after that name. Any default
+//! that cannot be resolved — no projects yet, no command, no generated
+//! name — downgrades the keystroke to a draft pane pre-filled with whatever
+//! did resolve ([`FastForwardDefaults::apply_to_draft`]).
+
+use std::path::PathBuf;
+
+use chrono::{DateTime, Utc};
+use maestro_protocol::{CreateSessionRequest, Project, SpawnPreset, WorktreeSpec};
+
+use crate::draft::DraftPane;
+
+/// What one fast-forward keystroke resolved. Every field optional: `None`
+/// anywhere means "open a draft instead of spawning".
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct FastForwardDefaults {
+    pub project: Option<Project>,
+    pub command: Option<String>,
+    pub name: Option<String>,
+}
+
+/// Resolve the fast-forward defaults from the daemon's answers. `name` is
+/// `None` when `/api/names` yielded nothing; `presets` may be empty (the
+/// caller falls back to the built-ins it already has).
+pub fn resolve(
+    projects: &[Project],
+    presets: &[SpawnPreset],
+    name: Option<String>,
+    now: DateTime<Utc>,
+) -> FastForwardDefaults {
+    let project = crate::projects::sort_projects(projects.to_vec(), now)
+        .into_iter()
+        .next();
+    let command = project
+        .as_ref()
+        .and_then(|p| p.last_command.clone())
+        .filter(|c| !c.trim().is_empty())
+        .or_else(|| {
+            presets
+                .iter()
+                .find(|p| !p.command.is_empty())
+                .map(|p| p.command.clone())
+        });
+    FastForwardDefaults {
+        project,
+        command,
+        name,
+    }
+}
+
+impl FastForwardDefaults {
+    /// The spawn request when *every* default resolved: worktree on, new
+    /// branch named after the generated session name, base repo from the
+    /// scan (`None` means the project is itself a main checkout).
+    pub fn build_request(&self) -> Option<CreateSessionRequest> {
+        let project = self.project.as_ref()?;
+        let command = self.command.as_deref()?.trim();
+        let name = self.name.as_deref()?;
+        if command.is_empty() || name.is_empty() {
+            return None;
+        }
+        let mut metadata = std::collections::HashMap::new();
+        metadata.insert(
+            "name".to_string(),
+            serde_json::Value::String(name.to_string()),
+        );
+        Some(CreateSessionRequest {
+            cwd: project.path.clone(),
+            command: command.to_string(),
+            env: Default::default(),
+            metadata,
+            worktree: Some(WorktreeSpec {
+                base_repo: project
+                    .base_repo
+                    .clone()
+                    .unwrap_or_else(|| project.path.clone()),
+                branch: name.to_string(),
+                create_branch: true,
+            }),
+        })
+    }
+
+    /// Seed a fresh draft pane with whatever did resolve — the fallback when
+    /// [`Self::build_request`] is `None`. The operator fills in the rest.
+    pub fn apply_to_draft(&self, draft: &mut DraftPane) {
+        if let Some(project) = &self.project {
+            draft.picked_cwd = Some(PathBuf::from(&project.path));
+            // The scan already knows this directory's repo (#61): no probe
+            // round trip needed, exactly like picking the row by hand.
+            draft.base_repo = Some(
+                project
+                    .base_repo
+                    .clone()
+                    .unwrap_or_else(|| project.path.clone()),
+            );
+            draft.probed_cwd = Some(PathBuf::from(&project.path));
+        }
+        if let Some(command) = &self.command {
+            if let Some(idx) = draft.presets.iter().position(|p| &p.command == command) {
+                draft.selected_preset = idx;
+            } else if !command.trim().is_empty() {
+                // A last_command no preset advertises lands in custom free text.
+                draft.selected_preset = draft.presets.len().saturating_sub(1);
+                draft.custom_command = crate::text_input::TextInput::with_value(command);
+            }
+        }
+        if let Some(name) = &self.name {
+            draft.set_name(name.clone());
+            // Seeded, not generated: a later refill must not clobber it.
+            draft.name_touched = true;
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use chrono::TimeDelta;
+
+    fn project(path: &str, days_ago: i64, cmd: Option<&str>) -> Project {
+        Project {
+            path: PathBuf::from(path),
+            name: path.rsplit('/').next().unwrap_or(path).into(),
+            is_worktree: false,
+            base_repo: None,
+            last_activity: Some(Utc::now() - TimeDelta::days(days_ago)),
+            last_command: cmd.map(String::from),
+        }
+    }
+
+    fn repo_project(path: &str, base: &str, days_ago: i64, cmd: Option<&str>) -> Project {
+        Project {
+            base_repo: Some(PathBuf::from(base)),
+            ..project(path, days_ago, cmd)
+        }
+    }
+
+    fn preset(id: &str, command: &str) -> SpawnPreset {
+        SpawnPreset {
+            id: id.into(),
+            label: id.into(),
+            command: command.into(),
+        }
+    }
+
+    #[test]
+    fn resolves_every_default_from_the_most_recent_project() {
+        let projects = vec![
+            project("/repos/old", 30, Some("zsh")),
+            repo_project("/repos/fresh", "/repos/fresh", 0, Some("claude")),
+        ];
+        let presets = vec![preset("aider", "aider"), preset("custom", "")];
+        let r = resolve(&projects, &presets, Some("amber-falcon".into()), Utc::now());
+        assert_eq!(
+            r.project.as_ref().unwrap().path,
+            PathBuf::from("/repos/fresh")
+        );
+        assert_eq!(r.command.as_deref(), Some("claude"));
+        assert_eq!(r.name.as_deref(), Some("amber-falcon"));
+
+        let req = r.build_request().expect("all defaults resolved");
+        assert_eq!(req.cwd, PathBuf::from("/repos/fresh"));
+        assert_eq!(req.command, "claude");
+        assert_eq!(
+            req.metadata.get("name").and_then(|v| v.as_str()),
+            Some("amber-falcon")
+        );
+        let wt = req.worktree.expect("worktree on");
+        assert_eq!(wt.base_repo, PathBuf::from("/repos/fresh"));
+        assert_eq!(wt.branch, "amber-falcon");
+        assert!(wt.create_branch, "fresh branch named after the session");
+    }
+
+    #[test]
+    fn worktree_of_the_most_recent_project_targets_its_base_repo() {
+        let projects = vec![repo_project("/repos/main/wt-x", "/repos/main", 0, None)];
+        let r = resolve(
+            &projects,
+            &[preset("zsh", "zsh")],
+            Some("s".into()),
+            Utc::now(),
+        );
+        let wt = r.build_request().unwrap().worktree.unwrap();
+        assert_eq!(wt.base_repo, PathBuf::from("/repos/main"));
+    }
+
+    #[test]
+    fn missing_last_command_falls_back_to_the_first_non_custom_preset() {
+        let projects = vec![project("/repos/p", 0, None)];
+        let presets = vec![preset("custom", ""), preset("claude", "claude")];
+        let r = resolve(&projects, &presets, Some("n".into()), Utc::now());
+        assert_eq!(r.command.as_deref(), Some("claude"));
+    }
+
+    #[test]
+    fn an_empty_last_command_is_no_command_at_all() {
+        let projects = vec![project("/repos/p", 0, Some(""))];
+        let presets = vec![preset("custom", "")];
+        let r = resolve(&projects, &presets, Some("n".into()), Utc::now());
+        assert_eq!(r.command, None);
+        assert!(r.build_request().is_none());
+    }
+
+    #[test]
+    fn nothing_resolves_when_no_projects_are_known_yet() {
+        let r = resolve(
+            &[],
+            &[preset("claude", "claude")],
+            Some("n".into()),
+            Utc::now(),
+        );
+        assert_eq!(r.project, None);
+        // No project → no directory → no request, even with command + name.
+        assert!(r.build_request().is_none());
+    }
+
+    #[test]
+    fn a_missing_generated_name_downgrades_to_a_draft() {
+        let projects = vec![project("/repos/p", 0, Some("claude"))];
+        let r = resolve(&projects, &[preset("claude", "claude")], None, Utc::now());
+        assert!(r.build_request().is_none(), "no name → no immediate spawn");
+    }
+
+    #[test]
+    fn unresolvable_defaults_still_seed_the_draft_with_what_resolved() {
+        let projects = vec![repo_project("/repos/p", "/repos/p", 0, Some("aider"))];
+        let r = resolve(&projects, &[preset("aider", "aider")], None, Utc::now());
+
+        let mut draft = DraftPane::default();
+        r.apply_to_draft(&mut draft);
+        assert_eq!(draft.cwd(), Some(PathBuf::from("/repos/p")));
+        assert_eq!(draft.base_repo, Some(PathBuf::from("/repos/p")));
+        assert_eq!(draft.command(), "aider");
+        assert!(
+            draft.name.value().is_empty(),
+            "nothing to seed the name with"
+        );
+        assert!(draft.worktree_enabled);
+    }
+
+    #[test]
+    fn a_resolved_name_survives_late_refills_and_tracks_the_branch() {
+        let projects = vec![project("/repos/p", 0, Some("claude"))];
+        let named = resolve(
+            &projects,
+            &[preset("claude", "claude")],
+            Some("amber-falcon".into()),
+            Utc::now(),
+        );
+        let mut draft = DraftPane::default();
+        named.apply_to_draft(&mut draft);
+        // A later batch must not overwrite the name the spawn was seeded with.
+        draft.seed_names(vec!["late-name".into()]);
+        assert_eq!(draft.name.value(), "amber-falcon");
+        assert_eq!(draft.branch.value(), "amber-falcon");
+    }
+
+    #[test]
+    fn an_unresolved_name_still_gets_generated_by_a_later_batch() {
+        let projects = vec![project("/repos/p", 0, Some("claude"))];
+        let r = resolve(&projects, &[preset("claude", "claude")], None, Utc::now());
+        let mut draft = DraftPane::default();
+        r.apply_to_draft(&mut draft);
+        draft.seed_names(vec!["late-name".into()]);
+        assert_eq!(draft.name.value(), "late-name");
+    }
+
+    #[test]
+    fn a_last_command_no_preset_advertises_lands_in_custom_text() {
+        let projects = vec![project("/repos/p", 0, Some("nvim -d"))];
+        let r = resolve(&projects, &[preset("claude", "claude")], None, Utc::now());
+        let mut draft = DraftPane::default();
+        r.apply_to_draft(&mut draft);
+        assert_eq!(draft.command(), "nvim -d");
+        assert!(draft.is_custom());
+    }
+}

crates/maestro-tui/src/input.rs

@@ -117,7 +117,9 @@ impl InputKey {
                 if *alt {
                     out.push_str("alt-");
                 }
-                if *shift {
+                // Uppercase already implies shift; crossterm sets the flag
+                // on every such char, so skip the redundant prefix (#70).
+                if *shift && !c.is_uppercase() {
                     out.push_str("shift-");
                 }
                 out.push(*c);
@@ -580,12 +582,28 @@ mod tests {
 
     #[test]
     fn canonical_round_trips_simple_chars() {
-        for s in ["a", "ctrl-a", "ctrl-w", "alt-x", "shift-A"] {
+        for s in ["a", "ctrl-a", "ctrl-w", "alt-x"] {
             let k = InputKey::parse(s).unwrap();
             assert_eq!(k.canonical(), s, "round-trip {s:?}");
         }
     }
 
+    /// crossterm 0.28 attaches `KeyModifiers::SHIFT` to any uppercase char,
+    /// so a real Shift+S delivers `Char { c: 'S', shift: true }`. Its
+    /// canonical form must be the bare `"S"` a keymap binds, not `"shift-S"` —
+    /// the uppercase letter already says "shifted"; a redundant prefix would
+    /// make the default `S` binding unreachable from the keyboard (#70).
+    #[test]
+    fn shift_flag_is_redundant_for_an_already_uppercase_char() {
+        let k = InputKey::Char {
+            c: 'S',
+            ctrl: false,
+            alt: false,
+            shift: true,
+        };
+        assert_eq!(k.canonical(), "S");
+    }
+
     #[test]
     fn canonical_round_trips_specials() {
         for s in [

crates/maestro-tui/src/lib.rs

@@ -9,6 +9,7 @@ pub mod cli;
 pub mod config;
 pub mod draft;
 pub mod emulators;
+pub mod fast_forward;
 pub mod input;
 pub mod keymap;
 pub mod overlays;
@@ -21,6 +22,7 @@ pub mod state;
 pub mod tabs;
 pub mod terminal;
 pub mod text_input;
+pub mod worktrees;
 
 use std::path::PathBuf;
 use std::time::Duration;

crates/maestro-tui/src/overlays.rs

@@ -14,23 +14,28 @@ use ratatui::Frame;
 #[derive(Debug, Clone)]
 pub struct KillConfirm {
     pub label: String,
+    /// #83: what the daemon's watcher last saw in the worktree, phrased by
+    /// [`maestro_protocol::InTheWay`]'s Display — so "this will be refused"
+    /// is visible before the attempt. `None` while nothing blocks.
+    pub blockers: Option<String>,
 }
 
 impl KillConfirm {
     pub fn render(&self, f: &mut Frame, parent: Rect) {
-        let area = centered(parent, 50, 5);
+        let area = centered(parent, 60, if self.blockers.is_some() { 6 } else { 5 });
         f.render_widget(Clear, area);
         let block = Block::default().title(" kill ").borders(Borders::ALL);
         let inner = block.inner(area);
         f.render_widget(block, area);
-        f.render_widget(
-            Paragraph::new(vec![
-                Line::from(format!("Kill session {}?", self.label)),
-                Line::from(""),
-                Line::from("[y] yes   [n] no"),
-            ]),
-            inner,
-        );
+        let mut lines = vec![Line::from(format!("Kill session {}?", self.label))];
+        if let Some(blockers) = &self.blockers {
+            // Same phrasing the reclaim confirmation uses for its own guard.
+            lines.push(Line::from(format!("Currently in the way: {blockers}")));
+            lines.push(Line::from("The kill will be refused unless forced."));
+        }
+        lines.push(Line::from(""));
+        lines.push(Line::from("[y] yes   [n] no"));
+        f.render_widget(Paragraph::new(lines), inner);
     }
 }
 
@@ -82,7 +87,7 @@ impl Toast {
     }
 }
 
-fn centered(parent: Rect, w: u16, h: u16) -> Rect {
+pub(crate) fn centered(parent: Rect, w: u16, h: u16) -> Rect {
     let w = w.min(parent.width);
     let h = h.min(parent.height);
     Rect {
@@ -121,6 +126,7 @@ mod tests {
     fn kill_confirm_renders_prompt() {
         let modal = KillConfirm {
             label: "session-7".into(),
+            blockers: None,
         };
         let rendered = render_to_string(60, 10, |f| modal.render(f, f.area()));
         assert!(rendered.contains("Kill"));
@@ -129,6 +135,22 @@ mod tests {
         assert!(rendered.contains("no"));
     }
 
+    /// #83: when the worktree blocks, the confirm names it before the
+    /// operator commits — in `InTheWay`'s own words.
+    #[test]
+    fn kill_confirm_names_what_blocks() {
+        let modal = KillConfirm {
+            label: "session-7".into(),
+            blockers: Some("2 uncommitted files".into()),
+        };
+        let rendered = render_to_string(70, 10, |f| modal.render(f, f.area()));
+        assert!(
+            rendered.contains("Currently in the way: 2 uncommitted files"),
+            "{rendered}"
+        );
+        assert!(rendered.contains("refused"), "{rendered}");
+    }
+
     #[test]
     fn help_overlay_lists_lines() {
         let help = HelpOverlay {

crates/maestro-tui/src/render.rs

@@ -15,6 +15,7 @@ use crate::pane::Pane;
 use crate::sidebar::Sidebar;
 use crate::state::{AppState, Focus, OverlayKind};
 use crate::tabs::TabBar;
+use crate::worktrees::{ReclaimConfirm, WorktreesView};
 
 /// Tagged regions for mouse hit-testing. The input router resolves a mouse
 /// coordinate to one of these via [`RegionMap::region_at`].
@@ -67,6 +68,8 @@ pub struct RenderInputs<'a> {
     pub draft: Option<&'a crate::draft::DraftPane>,
     pub state: &'a AppState,
     pub help: &'a HelpOverlay,
+    /// Retained-worktree entries for the worktrees view (#85).
+    pub worktrees: Option<&'a WorktreesView>,
 }
 
 /// Draw one frame. Returns the `RegionMap` the input router will consult for
@@ -143,8 +146,19 @@ pub fn draw(f: &mut Frame, inputs: RenderInputs<'_>) -> RegionMap {
 
     match inputs.state.overlay() {
         Some(OverlayKind::KillConfirm(id)) => {
+            // #83: surface what the watcher last saw in the worktree, in
+            // InTheWay's own words, before the operator commits to the kill.
+            let blockers = inputs
+                .sidebar
+                .sessions
+                .iter()
+                .find(|s| &s.id == id)
+                .and_then(|s| s.blocked_work)
+                .filter(|b| !b.is_clear())
+                .map(|b| b.to_string());
             let kc = KillConfirm {
                 label: id.to_string(),
+                blockers,
             };
             kc.render(f, area);
             map.modal = Some(area);
@@ -153,6 +167,22 @@ pub fn draw(f: &mut Frame, inputs: RenderInputs<'_>) -> RegionMap {
             inputs.help.render(f, area);
             map.modal = Some(area);
         }
+        Some(OverlayKind::Worktrees) => {
+            if let Some(view) = inputs.worktrees {
+                view.render(f, area);
+                map.modal = Some(area);
+            }
+        }
+        Some(OverlayKind::ReclaimConfirm {
+            branch, blockers, ..
+        }) => {
+            let rc = ReclaimConfirm {
+                branch: branch.clone(),
+                blockers: blockers.clone(),
+            };
+            rc.render(f, area);
+            map.modal = Some(area);
+        }
         Some(OverlayKind::Toast(text)) => {
             let t = Toast { text: text.clone() };
             t.render(f, area);
@@ -298,6 +328,7 @@ mod tests {
             draft: Some(draft),
             state: &state,
             help: &help,
+            worktrees: None,
         };
 
         let backend = ratatui::backend::TestBackend::new(80, 24);

crates/maestro-tui/src/sidebar.rs

@@ -52,6 +52,13 @@ impl Sidebar {
                 (SessionStatus::Running, false) => "○",
             };
             let label = name_for(s);
+            // #83: a session whose worktree blocks a kill gets a warning
+            // glyph; the kill confirm names the specifics.
+            let blocked = s
+                .blocked_work
+                .filter(|b| !b.is_clear())
+                .map(|_| " ⚠")
+                .unwrap_or_default();
             let style = if self.highlight == Some(s.id) {
                 Style::default().add_modifier(Modifier::REVERSED)
             } else {
@@ -59,7 +66,7 @@ impl Sidebar {
             };
             lines.push(Line::from(vec![
                 Span::raw("  "),
-                Span::styled(format!("{glyph} {label}"), style),
+                Span::styled(format!("{glyph} {label}{blocked}"), style),
             ]));
         }
         f.render_widget(Paragraph::new(lines), inner);
@@ -92,12 +99,14 @@ mod tests {
             cwd: std::path::PathBuf::from("/tmp"),
             env: Default::default(),
             metadata,
+            worktree: None,
             status: SessionStatus::Running,
             created_at: Utc::now(),
             foreground: None,
             activity: Default::default(),
             last_activity_at: chrono::Utc::now(),
             current_cwd: None,
+            blocked_work: None,
         }
     }
 
@@ -171,6 +180,40 @@ mod tests {
         assert!(line.contains('✗'), "expected dead glyph in: {line:?}");
     }
 
+    /// #83: a session whose worktree blocks a kill carries the warning glyph;
+    /// a clear or unprobed one does not.
+    #[test]
+    fn blocked_session_gets_a_warning_glyph() {
+        use maestro_protocol::InTheWay;
+
+        let mut blocked = session_named(1, "claude");
+        blocked.blocked_work = Some(InTheWay {
+            unpushed_commits: 4,
+            ..InTheWay::default()
+        });
+        let mut clear = session_named(2, "bash");
+        clear.blocked_work = Some(InTheWay::default());
+        let unprobed = session_named(3, "vim");
+        let sb = Sidebar {
+            sessions: vec![blocked, clear, unprobed],
+            highlight: None,
+            attached: Default::default(),
+        };
+        let rendered = render_to_string(&sb, 40, 8);
+        let line = rendered
+            .lines()
+            .find(|l| l.contains("claude"))
+            .expect("blocked row");
+        assert!(line.contains('⚠'), "expected warning glyph in: {line:?}");
+        for name in ["bash", "vim"] {
+            let line = rendered
+                .lines()
+                .find(|l| l.contains(name))
+                .expect("clear row");
+            assert!(!line.contains('⚠'), "{name} must not warn: {line:?}");
+        }
+    }
+
     #[test]
     fn falls_back_to_command_when_name_metadata_is_absent() {
         let s = Session {
@@ -179,6 +222,7 @@ mod tests {
             cwd: std::path::PathBuf::from("/tmp"),
             env: Default::default(),
             metadata: HashMap::new(),
+            worktree: None,
             status: SessionStatus::Running,
             created_at: Utc::now(),
             foreground: None,
@@ -186,6 +230,7 @@ mod tests {
             last_activity_at: chrono::Utc::now(),
 
             current_cwd: None,
+            blocked_work: None,
         };
         let sb = Sidebar {
             sessions: vec![s],

crates/maestro-tui/src/state.rs

@@ -50,6 +50,17 @@ pub enum OverlayKind {
     KillConfirm(Uuid),
     Help,
     Toast(String),
+    /// The retained-worktrees view (#85); its entries live on `App` because
+    /// they are daemon data, not UI state.
+    Worktrees,
+    /// Reclaim confirmation for the worktree with this id (#85), guarding
+    /// the destructive key like [`OverlayKind::KillConfirm`] does.
+    ReclaimConfirm {
+        id: Uuid,
+        branch: String,
+        /// [`maestro_protocol::InTheWay`] as of when the confirm was opened.
+        blockers: String,
+    },
 }
 
 #[derive(Debug)]

crates/maestro-tui/src/worktrees.rs

@@ -0,0 +1,259 @@
+//! Retained-worktrees view (#85): an overlay listing every retained worktree
+//! — branch, abbreviated path, reason, what is in the way — with j/k to move,
+//! `r` to reclaim behind a confirmation, esc to close.
+//!
+//! The in-the-way summary comes straight from [`InTheWay`]'s `Display` impl,
+//! the same source the kill refusal and the web client use, so no two clients
+//! can describe the same tree differently.
+
+use ratatui::layout::Rect;
+use ratatui::text::Line;
+use ratatui::widgets::{Block, Borders, Clear, Paragraph};
+use ratatui::Frame;
+
+use maestro_protocol::{RetainedReason, RetainedWorktree};
+
+use crate::draft::abbreviate_path;
+
+/// The open worktrees overlay: its entries and which one is highlighted.
+#[derive(Debug, Clone, Default)]
+pub struct WorktreesView {
+    pub items: Vec<RetainedWorktree>,
+    pub highlight: usize,
+    /// Daemon-reported home dir, for `~` abbreviation of paths.
+    pub home_dir: String,
+}
+
+impl WorktreesView {
+    /// Replace the listing and keep the highlight pointing at something real.
+    pub fn apply(&mut self, items: Vec<RetainedWorktree>) {
+        self.items = items;
+        if !self.items.is_empty() {
+            self.highlight = self.highlight.min(self.items.len() - 1);
+        } else {
+            self.highlight = 0;
+        }
+    }
+
+    pub fn remove(&mut self, id: uuid::Uuid) {
+        let idx = self.items.iter().position(|w| w.id == id);
+        self.items.retain(|w| w.id != id);
+        if let Some(i) = idx {
+            self.highlight = self.highlight.min(self.items.len().saturating_sub(1));
+            let _ = i;
+        }
+    }
+
+    /// Move the highlight by `delta` (positive = down). Wraps. No-op on empty.
+    pub fn move_highlight(&mut self, delta: i32) {
+        if self.items.is_empty() {
+            return;
+        }
+        let len = self.items.len() as i32;
+        let next = (self.highlight as i32 + delta).rem_euclid(len);
+        self.highlight = next as usize;
+    }
+
+    pub fn selected(&self) -> Option<&RetainedWorktree> {
+        self.items.get(self.highlight)
+    }
+
+    pub fn render(&self, f: &mut Frame, parent: Rect) {
+        let h = (self.items.len() as u16 + 6).clamp(4, parent.height);
+        let area = super::overlays::centered(parent, parent.width.saturating_sub(4), h);
+        f.render_widget(Clear, area);
+        let block = Block::default()
+            .title(" retained worktrees ")
+            .borders(Borders::ALL);
+        let inner = block.inner(area);
+        f.render_widget(block, area);
+
+        let mut lines: Vec<Line> = Vec::new();
+        if self.items.is_empty() {
+            // A drained store is the normal state — say so plainly, not like
+            // something went wrong.
+            lines.push(Line::from("no retained worktrees"));
+        } else {
+            lines.push(Line::from(format!(
+                "  {:<26}  {:<34}  {:<24}  IN THE WAY",
+                "BRANCH", "PATH", "REASON"
+            )));
+            for (i, w) in self.items.iter().enumerate() {
+                let marker = if i == self.highlight { ">" } else { " " };
+                lines.push(Line::from(format!(
+                    "{marker} {:<25}  {:<34}  {:<24}  {}",
+                    w.branch,
+                    abbreviate_path(&w.path, &self.home_dir),
+                    reason_label(w.reason),
+                    w.in_the_way,
+                )));
+            }
+        }
+        lines.push(Line::from(""));
+        lines.push(Line::from("j/k: select  r: reclaim  esc: close"));
+        f.render_widget(Paragraph::new(lines), inner);
+    }
+}
+
+/// The confirmation guarding reclaim, mirroring [`super::overlays::KillConfirm`].
+/// It names the branch and says out loud what reclaim does not take with it —
+/// docs/WORKTREES.md: "reclaim" otherwise sounds like it takes the commits too.
+#[derive(Debug, Clone)]
+pub struct ReclaimConfirm {
+    pub branch: String,
+    /// [`maestro_protocol::InTheWay`] rendered via its `Display` impl.
+    pub blockers: String,
+}
+
+impl ReclaimConfirm {
+    pub fn render(&self, f: &mut Frame, parent: Rect) {
+        let area = super::overlays::centered(parent, 70, 7);
+        f.render_widget(Clear, area);
+        let block = Block::default().title(" reclaim ").borders(Borders::ALL);
+        let inner = block.inner(area);
+        f.render_widget(block, area);
+        f.render_widget(
+            ratatui::widgets::Paragraph::new(vec![
+                Line::from(format!("Reclaim worktree {}?", self.branch)),
+                Line::from(format!("Currently in the way: {}", self.blockers)),
+                Line::from("The directory is removed; the branch is never deleted."),
+                Line::from(""),
+                Line::from("[y] yes   [n] no"),
+            ]),
+            inner,
+        );
+    }
+}
+
+fn reason_label(reason: RetainedReason) -> &'static str {
+    match reason {
+        RetainedReason::ForceKilled => "force-killed",
+        RetainedReason::ExitedWithUnsavedWork => "exited-with-unsaved-work",
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use chrono::{TimeZone, Utc};
+    use maestro_protocol::{InTheWay, RetainedReason};
+    use ratatui::backend::TestBackend;
+    use ratatui::Terminal;
+
+    fn render_to_string<F>(w: u16, h: u16, draw: F) -> String
+    where
+        F: FnOnce(&mut Frame),
+    {
+        let backend = TestBackend::new(w, h);
+        let mut terminal = Terminal::new(backend).unwrap();
+        terminal.draw(draw).unwrap();
+        let buf = terminal.backend().buffer().clone();
+        let mut out = String::new();
+        for y in 0..buf.area.height {
+            for x in 0..buf.area.width {
+                out.push_str(buf[(x, y)].symbol());
+            }
+            out.push('\n');
+        }
+        out
+    }
+
+    fn worktree(branch: &str, path: &str, id: u128) -> RetainedWorktree {
+        RetainedWorktree {
+            id: uuid::Uuid::from_u128(id),
+            path: path.into(),
+            base_repo: "/home/naps/tea/maestro".into(),
+            branch: branch.into(),
+            reason: RetainedReason::ForceKilled,
+            retained_at: Utc.with_ymd_and_hms(2026, 8, 24, 10, 0, 0).unwrap(),
+            in_the_way: InTheWay::default(),
+        }
+    }
+
+    #[test]
+    fn view_lists_branch_path_reason_and_what_is_in_the_way() {
+        let mut view = WorktreesView {
+            home_dir: "/home/naps".into(),
+            ..Default::default()
+        };
+        let mut wt = worktree(
+            "feat/login",
+            "/home/naps/tea/maestro/worktrees/feat/login",
+            1,
+        );
+        wt.in_the_way = InTheWay {
+            uncommitted_files: 2,
+            untracked_files: 1,
+            unpushed_commits: 3,
+        };
+        view.apply(vec![wt]);
+
+        let rendered = render_to_string(160, 20, |f| view.render(f, f.area()));
+        assert!(rendered.contains("feat/login"), "{rendered}");
+        // Path abbreviated against the daemon's home dir, same helper as the
+        // draft pane's project list.
+        assert!(rendered.contains("~/t/m/w/f/login"), "{rendered}");
+        assert!(rendered.contains("force-killed"), "{rendered}");
+        // Phrasing comes from InTheWay's Display impl — shared with the kill
+        // refusal and the web client.
+        assert!(
+            rendered.contains("2 uncommitted files, 1 untracked file, 3 unpushed commits"),
+            "{rendered}"
+        );
+    }
+
+    #[test]
+    fn empty_store_looks_like_a_normal_state_not_an_error() {
+        let view = WorktreesView::default();
+        let rendered = render_to_string(80, 12, |f| view.render(f, f.area()));
+        assert!(rendered.contains("no retained worktrees"), "{rendered}");
+        assert!(!rendered.contains("error"), "{rendered}");
+        assert!(!rendered.contains("failed"), "{rendered}");
+    }
+
+    #[test]
+    fn highlight_moves_and_wraps() {
+        let mut view = WorktreesView::default();
+        view.apply(vec![
+            worktree("a", "/r/a", 1),
+            worktree("b", "/r/b", 2),
+            worktree("c", "/r/c", 3),
+        ]);
+        assert_eq!(view.selected().unwrap().branch, "a");
+        view.move_highlight(1);
+        assert_eq!(view.selected().unwrap().branch, "b");
+        view.move_highlight(-1);
+        assert_eq!(view.selected().unwrap().branch, "a");
+        view.move_highlight(-1);
+        // Wraps backward to the last entry.
+        assert_eq!(view.selected().unwrap().branch, "c");
+        view.move_highlight(1);
+        assert_eq!(view.selected().unwrap().branch, "a");
+    }
+
+    #[test]
+    fn apply_clamps_a_stale_highlight() {
+        let mut view = WorktreesView::default();
+        view.apply(vec![worktree("a", "/r/a", 1), worktree("b", "/r/b", 2)]);
+        view.move_highlight(1);
+        view.apply(vec![worktree("c", "/r/c", 3)]);
+        assert_eq!(view.selected().unwrap().branch, "c");
+    }
+
+    #[test]
+    fn reclaim_confirm_names_the_branch_and_says_it_survives() {
+        let confirm = ReclaimConfirm {
+            branch: "feat/login".into(),
+            blockers: "2 uncommitted files".into(),
+        };
+        let rendered = render_to_string(80, 14, |f| confirm.render(f, f.area()));
+        assert!(
+            rendered.contains("Reclaim worktree feat/login?"),
+            "{rendered}"
+        );
+        assert!(rendered.contains("2 uncommitted files"), "{rendered}");
+        assert!(rendered.contains("never deleted"), "{rendered}");
+        assert!(rendered.contains("yes"), "{rendered}");
+        assert!(rendered.contains("no"), "{rendered}");
+    }
+}

docs/WORKTREES.md

@@ -0,0 +1,143 @@
+# Worktrees
+
+Maestro can create a git worktree for a session and is responsible for it from
+that moment until the worktree is removed. This document is the contract for
+that lifetime: where a worktree goes, what ends a session, what survives, and
+what the operator has to do by hand.
+
+It exists because the rules here are not guessable from the code. Every rule
+below was decided once, re-litigated in review, and decided the same way again.
+The reasoning is written down alongside each rule so the next reader does not
+have to reconstruct it.
+
+## Nothing is ever adopted
+
+The daemon only ever removes a worktree it created in this session's lifetime or
+recorded in its retained store. It never takes ownership of a directory it finds
+on disk, whatever that directory looks like.
+
+There is no reliable way to ask "is this worktree mine?". A git worktree carries
+no marker distinguishing one a daemon made from one a human made ten minutes
+earlier, and any heuristic that answers the question will eventually answer it
+wrong — in the direction of deleting somebody's work.
+
+So the daemon does not ask. If the target path is occupied by anything at all, it
+picks a different path.
+
+## Placement
+
+A worktree for branch `<branch>` of repository `<repo>` goes to
+`<repo>/worktrees/<branch>`, where `<repo>` is the main checkout — not whichever
+worktree the request happened to come from.
+
+The branch name is used verbatim as a relative path, so `feature/login` becomes
+`worktrees/feature/login`. A branch name that cannot be a relative path falls
+back to a short hash of the branch.
+
+If that path exists, the daemon appends `-2`, then `-3`, and so on until it finds
+a free one. The suffix names the **directory only**. The branch is whatever was
+requested; a second worktree of the same branch is not what happens here, because
+git refuses to check the same branch out twice and the branch picker already
+marks branches that are checked out elsewhere.
+
+### The `worktree_root` override
+
+`[daemon].worktree_root` moves every worktree out of the repository and under one
+root. The per-repository directory is the repository's basename plus a short
+digest of its full path — the digest is what keeps two repositories with the same
+basename apart. Inside it the layout and the collision suffix are the same.
+
+## What ends a session
+
+`DELETE /api/sessions/:id` is **refused** when the session's worktree holds
+unsaved work, meaning any of:
+
+- uncommitted changes to tracked files
+- untracked files that are not ignored
+- commits on the branch reachable from no remote-tracking ref
+
+Ignored files never block. Every Rust worktree has a `target/`; if ignored files
+counted, no session would ever be killable.
+
+The refusal is a structured error naming what blocked it and how much of it there
+is, so a client can say "3 uncommitted files, 2 unpushed commits". The session
+keeps running and the worktree is untouched.
+
+The point of refusing rather than cleaning up is that the session stays as the
+operator's handle on their own unfinished work. A session that is killed while
+its worktree still matters leaves a directory nobody is looking at.
+
+A consequence, accepted deliberately: a feature branch almost always has unpushed
+commits, so `--force` is the ordinary way to end a session, not an exception.
+That is only safe because force retains.
+
+### `--force`
+
+`--force` overrides the refusal and nothing else. It ends the session and
+**retains** the worktree, which enters the retained store with reason
+`force-killed`. Force never removes a tree that would have blocked. A tree
+whose guard is clear never needed the override, so a forced kill removes it as
+usual — force changes what happens to blocked work, not ordinary cleanup.
+
+Ending a session and destroying its work are two separate destructive acts.
+Each is chosen on its own, and the second one — reclaim — is chosen while
+looking at exactly what would be lost.
+
+A forced kill answers with what was retained and why, so a client can say where
+the work went rather than leaving the operator to wonder.
+
+### Exiting on its own
+
+A session that ends by itself — the command finished, the operator typed `exit` —
+never reaches the kill path. When the watcher notices the tmux session is gone it
+applies the same rule: a pristine worktree is removed, anything else is retained
+with reason `exited-with-unsaved-work`.
+
+Nobody is waiting for an answer here, so there is nothing to refuse; the choice is
+only between removing and retaining. It uses the same predicate as the kill, from
+the same place, so the two paths cannot drift apart.
+
+The session itself stays in the catalog marked dead until it is dismissed — the
+replay buffer of a crashed agent outlives it — but its worktree is settled at
+once. Once settled, the session drops its worktree reference, so dismissing it
+afterwards neither refuses (there is no guard left to trip) nor records a second
+store entry.
+
+If settling is impossible — the probe fails, or the store cannot take the entry —
+nothing is destroyed. The tree stays on disk *and* stays attached to the dead
+record, where dismissing it later still goes through `--force`'s
+retain-before-teardown path. Losing the store must never mean losing the work.
+
+## The retained store
+
+A `state_dir`-backed record of worktrees the daemon created that no longer have a
+session. For each one: the path, the base repository, the branch, why it was
+retained, and when.
+
+It survives a daemon restart. It is the recovery path for everything above — a
+store that is lost on restart is worse than no store, because the worktrees are
+still on disk with nothing pointing at them.
+
+Entries leave when the worktree is reclaimed, and when the daemon notices the
+directory is gone because somebody removed it by hand.
+
+**It is not an ownership record.** It must never be consulted to decide whether a
+path may be adopted — see the first rule. Its only job is to remember what the
+daemon is holding so that it can be listed and reclaimed.
+
+## Reclaim
+
+`GET /api/worktrees` lists the store: path, base repository, branch, reason, when,
+and what is currently in the way. The in-the-way breakdown is recomputed on read,
+not stored, so a tree whose work has since been pushed says so.
+
+`DELETE /api/worktrees/<id>` reclaims one. It removes the directory and drops the
+store entry. It does **not** consult the guard — reclaim is the deliberate
+destructive act, and the operator chose it while looking at what was in the way.
+
+It never deletes the branch. `git worktree remove` leaves the ref, and reclaiming
+a tree must not throw away commits on it. This is worth saying out loud in every
+client, because "reclaim" otherwise sounds like it takes the commits too.
+
+Nothing is reclaimed automatically. There is no age-based expiry and no bulk
+reclaim.

flake.nix

@@ -125,7 +125,7 @@
             pnpmDeps = (pkgs.fetchPnpmDeps.override { pnpm = pkgs.pnpm_10; }) {
               inherit (finalAttrs) pname version src;
               fetcherVersion = 3;
-              hash = "sha256-Lhi41AtCK69SM4+7zih19+Njf7o2hyXrAV0W6VO9YxU=";
+              hash = "sha256-D9JdgI92vzAY8en2zGEEPd4hwOLVi3sr1joT4b17Be4=";
             };
 
             buildPhase = ''

web/src/api.ts

@@ -9,6 +9,7 @@ import type {
   NameBatch,
   Projects,
   RecentDirs,
+  RetainedWorktree,
   Session,
   Uuid,
 } from "./types.js";
@@ -97,4 +98,22 @@ export async function fetchBranches(path: string): Promise<Branches> {
   return jsonOrError(await fetch(url, { credentials: "same-origin" }));
 }
 
+/** The daemon's retained worktrees (#80): trees kept after a session ended
+ * with unsaved work, with what is currently in the way. Drives the
+ * retained-worktrees view (#84). */
+export async function listWorktrees(): Promise<RetainedWorktree[]> {
+  return jsonOrError(await fetch(routes.WORKTREES, { credentials: "same-origin" }));
+}
+
+/** Reclaim a retained worktree: removes its directory and drops the store
+ * entry. Never deletes the branch (docs/WORKTREES.md). */
+export async function reclaimWorktree(id: Uuid): Promise<void> {
+  await jsonOrError(
+    await fetch(routes.worktree(id), {
+      method: "DELETE",
+      credentials: "same-origin",
+    }),
+  );
+}
+
 export { eventsWsUrl } from "./routes.js";

web/src/catalog.test.ts

@@ -0,0 +1,106 @@
+// @vitest-environment happy-dom
+import { beforeAll, describe, expect, it } from "vitest";
+
+import { renderSidebar } from "./catalog.js";
+import type { CatalogListener, CatalogStore } from "./events.js";
+import type { InTheWay, Session } from "./types.js";
+
+// happy-dom runs without a backing store; renderSidebar reads the persisted
+// sidebar width on mount.
+beforeAll(() => {
+  Object.defineProperty(window, "localStorage", {
+    value: { getItem: () => null, setItem: () => {} },
+  });
+  // No daemon here; renderSidebar treats a failed info fetch as "absolute
+  // paths are a fine fallback".
+  window.fetch = () => Promise.reject(new Error("offline"));
+});
+
+function session(overrides: Partial<Session>): Session {
+  return {
+    id: "11111111-2222-3333-4444-555555555555",
+    cwd: "/home/naps/tea/maestro",
+    command: "claude",
+    env: {},
+    metadata: {},
+    status: "Running",
+    created_at: "2026-08-24T10:00:00Z",
+    ...overrides,
+  };
+}
+
+function storeWith(sessions: Session[]): CatalogStore {
+  const state = { sessions: new Map(sessions.map((s) => [s.id, s])) };
+  return {
+    snapshot: () => state,
+    // Like the real store, deliver an immediate snapshot so the sidebar
+    // renders its rows during construction.
+    subscribe: (fn: CatalogListener) => {
+      fn(state);
+      return () => {};
+    },
+  } as unknown as CatalogStore;
+}
+
+function rowFor(el: HTMLElement, id: string): HTMLElement | null {
+  return el.querySelector<HTMLElement>(`[data-session-id="${id}"]`);
+}
+
+describe("blocked-work indicator (#83)", () => {
+  it("marks the row of a blocked session with the shared phrasing", () => {
+    const blocked = session({
+      id: "aaaaaaaa-0000-0000-0000-000000000001",
+      blocked_work: { uncommitted_files: 3, unpushed_commits: 2 },
+    });
+    const el = renderSidebar(storeWith([blocked])).el;
+    const badge = rowFor(el, blocked.id)?.querySelector(".leaf-blocked");
+    expect(badge?.textContent).toContain("⚠");
+    expect(badge?.textContent).toContain("3 uncommitted files, 2 unpushed commits");
+  });
+
+  it("does not mark clear or unprobed sessions", () => {
+    const clear = session({
+      id: "aaaaaaaa-0000-0000-0000-000000000002",
+      blocked_work: {} as InTheWay,
+    });
+    const unprobed = session({
+      id: "aaaaaaaa-0000-0000-0000-000000000003",
+    });
+    const el = renderSidebar(storeWith([clear, unprobed])).el;
+    expect(rowFor(el, clear.id)?.querySelector(".leaf-blocked")).toBeNull();
+    expect(rowFor(el, unprobed.id)?.querySelector(".leaf-blocked")).toBeNull();
+  });
+
+  it("restates the warning at the kill confirm", async () => {
+    const confirmations: string[] = [];
+    window.confirm = (msg?: string) => {
+      confirmations.push(msg ?? "");
+      return false;
+    };
+    const blocked = session({
+      id: "aaaaaaaa-0000-0000-0000-000000000004",
+      command: "bash",
+      blocked_work: { untracked_files: 1 },
+    });
+    const el = renderSidebar(storeWith([blocked])).el;
+    const kill = rowFor(el, blocked.id)?.querySelector<HTMLButtonElement>(".leaf-kill");
+    kill?.click();
+    await Promise.resolve();
+    expect(confirmations).toHaveLength(1);
+    expect(confirmations[0]).toContain("1 untracked file");
+    expect(confirmations[0]).toContain("refused unless forced");
+  });
+
+  it("confirms plainly when nothing blocks", async () => {
+    const confirmations: string[] = [];
+    window.confirm = (msg?: string) => {
+      confirmations.push(msg ?? "");
+      return false;
+    };
+    const plain = session({ id: "aaaaaaaa-0000-0000-0000-000000000005" });
+    const el = renderSidebar(storeWith([plain])).el;
+    rowFor(el, plain.id)?.querySelector<HTMLButtonElement>(".leaf-kill")?.click();
+    await Promise.resolve();
+    expect(confirmations).toEqual(['Kill session "claude"?']);
+  });
+});

web/src/catalog.ts

@@ -3,7 +3,7 @@ import { getDaemonInfo, killSession } from "./api.js";
 import { HUD_TOGGLE_EVENT, isHudEnabled, toggleHud } from "./debug.js";
 import { CatalogStore } from "./events.js";
 import type { Session } from "./types.js";
-import { abbreviateFolderName, sessionName } from "./types.js";
+import { abbreviateFolderName, formatInTheWay, sessionBlockers, sessionName } from "./types.js";
 import type { TreeNode } from "./tree.js";
 import { buildTree } from "./tree.js";
 import { createThemeToggle } from "./theme.js";
@@ -64,10 +64,14 @@ function renderNode(node: TreeNode, depth: number): HTMLElement {
   // The directory is the enclosing folder, so only surface the command — and
   // only when it isn't already what the name shows.
   const showCmd = s.command !== name;
+  // #83: warn on the row itself, in `formatInTheWay`'s shared phrasing, so
+  // "this will be refused" is visible before the kill is attempted.
+  const blockers = sessionBlockers(s);
   row.innerHTML = `
     <span class="leaf-name">${escapeHtml(name)}</span>
     ${showCmd ? `<span class="leaf-meta"><span class="leaf-cmd">${escapeHtml(s.command)}</span></span>` : ""}
     ${running ? "" : `<span class="leaf-badge">exited</span>`}
+    ${blockers ? `<span class="leaf-badge leaf-blocked" title="Kill will be refused unless forced">⚠ ${escapeHtml(formatInTheWay(blockers))}</span>` : ""}
     <span class="leaf-actions">
       <button class="leaf-act leaf-clone" type="button" title="Spawn similar" aria-label="Spawn similar to ${escapeHtml(name)}">⧉</button>
       <button class="leaf-act leaf-kill" type="button" title="Kill session" aria-label="Kill ${escapeHtml(name)}">✕</button>
@@ -83,7 +87,12 @@ function renderNode(node: TreeNode, depth: number): HTMLElement {
   killBtn.addEventListener("click", async (ev) => {
     ev.preventDefault();
     ev.stopPropagation();
-    if (!confirm(`Kill session "${sessionName(s)}"?`)) return;
+    // #83: the confirm restates the warning at the moment of decision.
+    const blockers = sessionBlockers(s);
+    const question = blockers
+      ? `Kill session "${name}"? Its worktree still has ${formatInTheWay(blockers)} — the kill will be refused unless forced.`
+      : `Kill session "${name}"?`;
+    if (!confirm(question)) return;
     try {
       await killSession(s.id);
     } catch (e) {
@@ -180,6 +189,15 @@ export function renderTopbar(store: CatalogStore, onToggleSidebar?: () => void):
   renderStatus();
 
   const actions = header.querySelector(".app-actions") as HTMLElement;
+  // Retained worktrees (#84): a section reachable from the header, not a
+  // sidebar fixture — PRODUCT.md's scan is the product, so this must not
+  // compete with the session catalog for attention.
+  const worktreesLink = document.createElement("a");
+  worktreesLink.className = "btn btn-ghost";
+  worktreesLink.href = "#/worktrees";
+  worktreesLink.textContent = "worktrees";
+  worktreesLink.title = "Retained worktrees";
+  actions.appendChild(worktreesLink);
   // DEV-only shortcut to the standalone design kit (?kit). Lets you reach it by
   // clicking inside a proxied preview (e.g. crit live) that has no address bar.
   if (import.meta.env.DEV) {
@@ -196,6 +214,8 @@ export function renderTopbar(store: CatalogStore, onToggleSidebar?: () => void):
   spawnBtn.type = "button";
   spawnBtn.className = "btn btn-primary spawn-btn";
   spawnBtn.textContent = "+ Spawn";
+  // The keyboard pair sits right here in the tooltip (#67).
+  spawnBtn.title = "Draft pane: n — fast-forward spawn: N";
   spawnBtn.addEventListener("click", () => requestOpenSpawn());
   actions.appendChild(spawnBtn);
   return header;

web/src/fastForward.test.ts

@@ -0,0 +1,95 @@
+import { describe, expect, it } from "vitest";
+import {
+  buildFastForwardRequest,
+  fastForwardSeed,
+  resolveFastForward,
+} from "./fastForward.js";
+import type { Project, SpawnPreset } from "./types.js";
+
+const presets: SpawnPreset[] = [
+  { id: "custom", label: "Custom…", command: "" },
+  { id: "claude", label: "Claude", command: "claude" },
+];
+
+function project(overrides: Partial<Project>): Project {
+  return {
+    path: "/repos/p",
+    name: "p",
+    last_activity: new Date().toISOString(),
+    ...overrides,
+  };
+}
+
+describe("resolveFastForward (#67)", () => {
+  it("resolves every default from the most recent project", () => {
+    const projects = [
+      project({ path: "/repos/old", name: "old", last_activity: "2020-01-01T00:00:00Z" }),
+      project({
+        path: "/repos/fresh",
+        name: "fresh",
+        base_repo: "/repos/fresh",
+        last_command: "aider",
+      }),
+    ];
+    const res = resolveFastForward(projects, presets, "amber-falcon");
+    expect(res.project?.path).toBe("/repos/fresh");
+    expect(res.command).toBe("aider");
+    expect(res.name).toBe("amber-falcon");
+
+    const req = buildFastForwardRequest(res)!;
+    expect(req.cwd).toBe("/repos/fresh");
+    expect(req.command).toBe("aider");
+    expect(req.metadata).toEqual({ name: "amber-falcon" });
+    expect(req.worktree).toEqual({
+      base_repo: "/repos/fresh",
+      branch: "amber-falcon",
+      create_branch: true,
+    });
+  });
+
+  it("falls back to the first non-custom preset when there is no last command", () => {
+    const res = resolveFastForward([project({ last_command: undefined })], presets, "n");
+    expect(res.command).toBe("claude");
+  });
+
+  it("treats an empty last command as no command", () => {
+    const res = resolveFastForward([project({ last_command: "" })], [presets[0]], "n");
+    expect(res.command).toBeUndefined();
+    expect(buildFastForwardRequest(res)).toBeNull();
+  });
+
+  it("resolves nothing when no projects are known yet", () => {
+    const res = resolveFastForward([], presets, "n");
+    expect(res.project).toBeUndefined();
+    expect(buildFastForwardRequest(res)).toBeNull();
+  });
+
+  it("downgrades to a draft when the generated name is missing", () => {
+    const res = resolveFastForward([project({ last_command: "claude" })], presets);
+    expect(res.name).toBeUndefined();
+    expect(buildFastForwardRequest(res)).toBeNull();
+  });
+
+  it("seeds the fallback draft with whatever did resolve", () => {
+    const res = resolveFastForward(
+      [project({ path: "/repos/p", base_repo: "/repos/p", last_command: "aider" })],
+      presets,
+    );
+    expect(fastForwardSeed(res)).toEqual({
+      cwd: "/repos/p",
+      command: "aider",
+      name: "",
+      worktreeEnabled: true,
+      worktreeBranch: undefined,
+    });
+  });
+
+  it("leaves the worktree default alone when not even a project resolved", () => {
+    // Not `false`: the form defaults the toggle on and a false would stick,
+    // so the fallback draft would disagree with a normally-opened draft and
+    // with the TUI's fast path.
+    const seed = fastForwardSeed(resolveFastForward([], presets));
+    expect(seed.worktreeEnabled).toBeUndefined();
+    expect(seed.cwd).toBe("");
+  });
+});

web/src/fastForward.ts

@@ -0,0 +1,65 @@
+// Fast-forward spawn (#67): one keystroke, every default resolved, no form.
+// Pure resolution only — the caller (main.ts) owns the fetches and the POST,
+// and falls back to a seeded draft pane when anything is missing.
+
+import type { CreateSessionRequest, Project, SpawnPreset } from "./types.js";
+import { sortProjects } from "./projectList.js";
+
+/** What one fast-forward keystroke resolved. Anything absent means "open a
+ *  draft pre-filled with the rest instead of spawning". */
+export interface FastForwardResolution {
+  project?: Project;
+  command?: string;
+  name?: string;
+}
+
+/** The defaults: most recent project (fresh-first, same ordering the picker
+ *  shows), its last command falling back to the first non-custom preset, and
+ *  a freshly generated name when the daemon supplied one. */
+export function resolveFastForward(
+  projects: Project[],
+  presets: SpawnPreset[],
+  name?: string,
+): FastForwardResolution {
+  const project = sortProjects(projects, new Date())[0];
+  const lastCommand = project?.last_command?.trim();
+  const command =
+    lastCommand || presets.find((p) => p.command !== "")?.command || undefined;
+  return { project, command, name: name || undefined };
+}
+
+/** The immediate spawn request — worktree on, new branch named after the
+ *  generated session name — or `null` when any default is missing. */
+export function buildFastForwardRequest(
+  res: FastForwardResolution,
+): CreateSessionRequest | null {
+  const { project, command, name } = res;
+  if (!project || !command?.trim() || !name) return null;
+  return {
+    cwd: project.path,
+    command,
+    metadata: { name },
+    worktree: {
+      base_repo: project.base_repo ?? project.path,
+      branch: name,
+      create_branch: true,
+    },
+  };
+}
+
+/** Seed for the fallback draft pane: whatever did resolve goes into the
+ *  form; the rest stays with its own defaults. */
+export function fastForwardSeed(res: FastForwardResolution) {
+  return {
+    cwd: res.project?.path ?? "",
+    command: res.command ?? "",
+    name: res.name ?? "",
+    // Left undefined rather than false when nothing resolved: the form
+    // defaults the toggle on, and `false` would stick, so the fallback draft
+    // would disagree with both a normally-opened draft and the TUI's fast path
+    // (#67 review).
+    worktreeEnabled: res.project ? true : undefined,
+    worktreeBranch:
+      res.project && res.name ? res.name : undefined,
+  };
+}

web/src/main.ts

@@ -3,13 +3,28 @@ import { ConnectionPool } from "./connections.js";
 import { installHudKeybind } from "./debug.js";
 import { CatalogStore } from "./events.js";
 import { shouldRetryClose } from "./reconnect.js";
+import {
+  createSession,
+  fetchNames,
+  getDaemonInfo,
+  listWorktrees,
+  projects as fetchProjects,
+  reclaimWorktree,
+} from "./api.js";
+import {
+  buildFastForwardRequest,
+  fastForwardSeed,
+  resolveFastForward,
+} from "./fastForward.js";
+import { FALLBACK_PRESETS } from "./spawnForm.js";
 import { mountHud, type Hud } from "./hud.js";
 import { emptyLayout, type Layout, openSessions } from "./layout.js";
 import { createMultiView, type MultiView } from "./multiview.js";
 import { loadLayout, saveLayout } from "./persistence.js";
 import { OPEN_SPAWN_EVENT } from "./catalog.js";
 import { initTheme } from "./theme.js";
-import { sessionName, type Session } from "./types.js";
+import { sessionName, type Project, type Session, type SpawnPreset } from "./types.js";
+import { createWorktreesView, type WorktreesViewHandle } from "./worktreesView.js";
 import { installViewportSizing } from "./viewport.js";
 import "./styles.css";
 
@@ -212,6 +227,7 @@ function renderWelcome(): HTMLElement {
   spawn.type = "button";
   spawn.className = "btn btn-primary";
   spawn.textContent = "+ Spawn session";
+  spawn.title = "Draft pane: n — fast-forward spawn: N";
   spawn.addEventListener("click", () => requestOpenSpawn());
   (el.querySelector(".empty-actions") as HTMLElement).appendChild(spawn);
   return el;
@@ -265,19 +281,114 @@ document.addEventListener("catalog-spawn-similar", (ev) => {
   mv.openDraft({ cwd: s.cwd, command: s.command });
 });
 
+// Fast-forward spawn (#67): the draft pane's keystroke neighbour spawns
+// immediately with every default resolved — most recent project, its last
+// command (or the first non-custom preset), a fresh name, worktree on with
+// a new branch named after that name. Anything unresolvable (no projects
+// known yet, no command, no generated name) opens a draft pre-filled with
+// what did resolve instead.
+async function requestFastForward(): Promise<void> {
+  showMultiView();
+  const [discovered, name] = await Promise.all([
+    fetchProjects().catch(() => [] as Project[]),
+    fetchNames(1)
+      .then((batch) => batch.names[0])
+      .catch(() => undefined),
+  ]);
+  let presets: SpawnPreset[] = FALLBACK_PRESETS;
+  try {
+    const info = await getDaemonInfo();
+    if (info.presets?.length) presets = info.presets;
+  } catch {
+    /* keep fallbacks */
+  }
+  const resolved = resolveFastForward(discovered, presets, name);
+  const req = buildFastForwardRequest(resolved);
+  if (req) {
+    try {
+      const session = await createSession(req);
+      // Mount it, the way the TUI's fast path attaches. Without this the
+      // keystroke creates a session and leaves the UI untouched, so it reads
+      // as a dead key (#67 review).
+      mv.openSessionBeside(session.id);
+      updateShellRoute();
+      return;
+    } catch {
+      // A failed POST degrades to the same pre-filled draft as an
+      // unresolvable default — never a silent dead keystroke.
+    }
+  }
+  mv.openDraft(fastForwardSeed(resolved));
+}
+
+// Keyboard pair (#67): `n` opens a draft pane, `N` fast-forwards a spawn.
+// Ignored while typing anywhere (form fields, the terminal's hidden
+// textarea, search) so an attached session's keys are never hijacked.
+document.addEventListener("keydown", (e) => {
+  if (e.ctrlKey || e.altKey || e.metaKey) return;
+  const target = e.target as HTMLElement | null;
+  if (
+    target &&
+    (target.tagName === "INPUT" ||
+      target.tagName === "TEXTAREA" ||
+      target.tagName === "SELECT" ||
+      target.isContentEditable)
+  ) {
+    return;
+  }
+  if (e.key === "n") {
+    e.preventDefault();
+    requestOpenSpawn();
+  } else if (e.key === "N") {
+    e.preventDefault();
+    void requestFastForward();
+  }
+});
+
 type Route =
   | { kind: "catalog" }
   | { kind: "attach"; sessionId: string }
+  | { kind: "worktrees" }
   | { kind: "not-found"; raw: string };
 
 function parseRoute(): Route {
   const hash = location.hash.replace(/^#/, "");
   if (hash === "" || hash === "/") return { kind: "catalog" };
+  if (hash === "/worktrees") return { kind: "worktrees" };
   const m = hash.match(/^\/attach\/([^/?#]+)$/);
   if (m) return { kind: "attach", sessionId: decodeURIComponent(m[1]) };
   return { kind: "not-found", raw: hash };
 }
 
+// Retained worktrees (#84): built lazily on first visit, then kept so a
+// revisit re-enters instantly. The daemon's home dir abbreviates paths once
+// `/api/info` answers.
+let worktreesView: WorktreesViewHandle | undefined;
+let homeDir: string | undefined;
+void getDaemonInfo()
+  .then((info) => {
+    homeDir = info.home_dir;
+  })
+  .catch(() => {
+    /* absolute paths are a fine fallback */
+  });
+
+function showWorktrees(): void {
+  pool.setVisible([]);
+  pool.setFocus(null);
+  contentShowsMv = false;
+  if (!worktreesView) {
+    worktreesView = createWorktreesView({
+      load: listWorktrees,
+      reclaim: reclaimWorktree,
+      homeDir: () => homeDir,
+    });
+  }
+  content.replaceChildren(worktreesView.el);
+  shellEl.dataset.route = "worktrees";
+  void worktreesView.refresh();
+}
+
 function dispatch(): void {
   const route = parseRoute();
   switch (route.kind) {
@@ -299,6 +410,9 @@ function dispatch(): void {
       // tears panes down.
       showMultiView();
       return;
+    case "worktrees":
+      showWorktrees();
+      return;
   }
 }
 

web/src/multiview.test.ts

@@ -147,6 +147,48 @@ describe("multiview openDraft (#62)", () => {
     expect((mv.el.querySelector(".mv-draft input[name=name]") as HTMLInputElement).value).toBe("wip");
   });
 
+  it("reuses an already-synced empty pane instead of splitting (#72)", async () => {
+    const layout = emptyLayout();
+    const tab = layout.tabs[0];
+    const first = splitLeaf(tab, "", "s1", "row", true);
+    const empty = splitLeaf(tab, first, null, "row", true);
+    tab.focusedLeafId = empty;
+    const mv = makeMv(layout);
+    document.body.appendChild(mv.el);
+    mv.render();
+    // Let the mounted form's loadProjects() settle and auto-sync its picked
+    // defaults into leaf.draft before openDraft runs (#72's dead-branch window).
+    await flush();
+    expect(leaves(tab.root).find((l) => l.id === empty)?.draft).not.toBeNull();
+
+    mv.openDraft();
+    await flush();
+
+    expect(leaves(tab.root)).toHaveLength(2);
+    expect(tab.focusedLeafId).toBe(empty);
+  });
+
+  it("keeps a seed after reusing an already-synced empty pane (#72)", async () => {
+    const layout = emptyLayout();
+    const tab = layout.tabs[0];
+    const first = splitLeaf(tab, "", "s1", "row", true);
+    const empty = splitLeaf(tab, first, null, "row", true);
+    tab.focusedLeafId = empty;
+    const mv = makeMv(layout);
+    document.body.appendChild(mv.el);
+    mv.render();
+    await flush();
+
+    mv.openDraft({ cwd: "/home/user/proj", command: "claude" });
+    await flush();
+
+    const leaf = leaves(tab.root).find((l) => l.id === empty)!;
+    expect(leaf.draft?.cwd).toBe("/home/user/proj");
+    expect(leaf.draft?.command).toBe("claude");
+    const cwdRaw = mv.el.querySelector(".mv-draft .cwd-raw") as HTMLInputElement;
+    expect(cwdRaw.value).toBe("/home/user/proj");
+  });
+
   it("seeds a clone's cwd and command into the draft", async () => {
     const layout = emptyLayout();
     const mv = makeMv(layout);
@@ -160,3 +202,83 @@ describe("multiview openDraft (#62)", () => {
     expect(leaf.draft?.command).toBe("claude");
   });
 });
+
+describe("multiview pane-drag swap (#73)", () => {
+  beforeEach(() => {
+    stubFetch();
+    document.body.replaceChildren();
+  });
+
+  afterEach(() => {
+    vi.unstubAllGlobals();
+    vi.restoreAllMocks();
+  });
+
+  /** Drag `sourcePane`'s title onto `targetPane`'s center, as the real pane
+   *  drag handler does — modelled after the pointer sequence in runDrag()/
+   *  updateDock() in multiview.ts, since neither is exposed on MultiView. */
+  async function dragPaneOntoCenter(sourcePane: HTMLElement, targetPane: HTMLElement): Promise<void> {
+    // The real drag-start gate requires the pointerdown target to sit inside
+    // an `.attach-header` (attach.ts's session title bar). Draft panes mount
+    // no such element, so stand one in for the gate check itself.
+    const marker = document.createElement("div");
+    marker.className = "attach-header";
+    sourcePane.appendChild(marker);
+
+    vi.spyOn(targetPane, "getBoundingClientRect").mockReturnValue({
+      left: 100,
+      top: 0,
+      width: 100,
+      height: 100,
+      right: 200,
+      bottom: 100,
+      x: 100,
+      y: 0,
+      toJSON() {},
+    } as DOMRect);
+    (document as unknown as { elementsFromPoint: (x: number, y: number) => Element[] }).elementsFromPoint = () => [
+      targetPane,
+    ];
+
+    marker.dispatchEvent(
+      new PointerEvent("pointerdown", { clientX: 0, clientY: 0, bubbles: true, cancelable: true }),
+    );
+    window.dispatchEvent(
+      new PointerEvent("pointermove", { clientX: 150, clientY: 50, bubbles: true, cancelable: true }),
+    );
+    window.dispatchEvent(new PointerEvent("pointerup", { clientX: 150, clientY: 50, bubbles: true, cancelable: true }));
+    await flush();
+  }
+
+  it("moves each draft's form along with its data when two draft panes are swapped", async () => {
+    const layout = emptyLayout();
+    const tab = layout.tabs[0];
+    const leaf1 = splitLeaf(tab, "", null, "row", true);
+    const leaf2 = splitLeaf(tab, leaf1, null, "row", true);
+    const mv = makeMv(layout);
+    document.body.appendChild(mv.el);
+    mv.render();
+    await flush();
+
+    const paneOf = (leafId: string) => mv.el.querySelector(`[data-leaf-id="${leafId}"]`) as HTMLElement;
+    const nameInputOf = (leafId: string) => paneOf(leafId).querySelector("input[name=name]") as HTMLInputElement;
+
+    nameInputOf(leaf1).value = "west";
+    nameInputOf(leaf1).dispatchEvent(new Event("input"));
+    nameInputOf(leaf2).value = "east";
+    nameInputOf(leaf2).dispatchEvent(new Event("input"));
+    await flush();
+    expect(leaves(tab.root).find((l) => l.id === leaf1)?.draft?.name).toBe("west");
+    expect(leaves(tab.root).find((l) => l.id === leaf2)?.draft?.name).toBe("east");
+
+    await dragPaneOntoCenter(paneOf(leaf1), paneOf(leaf2));
+
+    // The leaf data swaps (already correct pre-fix)...
+    expect(leaves(tab.root).find((l) => l.id === leaf1)?.draft?.name).toBe("east");
+    expect(leaves(tab.root).find((l) => l.id === leaf2)?.draft?.name).toBe("west");
+    // ...and the mounted forms must follow, not stay behind showing the old
+    // pane's values (#73).
+    expect(nameInputOf(leaf1).value).toBe("east");
+    expect(nameInputOf(leaf2).value).toBe("west");
+  });
+});

web/src/multiview.ts

@@ -49,6 +49,7 @@ export interface MultiView {
   /** Bring a session into the layout: focus it if already open, else fill the
    *  focused pane (or open the first pane in an empty tab). */
   openSession: (sessionId: string) => void;
+  openSessionBeside: (sessionId: string) => void;
   /** Drop the pane showing `sessionId` (the session was disconnected/killed). */
   closeSession: (sessionId: string) => void;
   /** Every session currently shown in some pane, across all tabs. */
@@ -378,6 +379,39 @@ export function createMultiView(opts: MultiViewOptions): MultiView {
     render();
   }
 
+  /// Mount a session without evicting one.
+  ///
+  /// `openSession` deliberately replaces the focused pane (VS Code style) for
+  /// a sidebar click, but the fast path must never do that: pressing the key
+  /// while attached would drop the running session out of the layout
+  /// entirely. Follows `openDraft`'s rule instead — reuse an empty pane, else
+  /// split beside the focused one (#67 review).
+  function openSessionBeside(sessionId: string): void {
+    const loc = locateSession(layout, sessionId);
+    if (loc) {
+      layout.activeTabId = loc.tab.id;
+      loc.tab.focusedLeafId = loc.leaf.id;
+      render();
+      return;
+    }
+    const tab = activeTab(layout);
+    if (!tab.root || !tab.focusedLeafId || !findLeaf(tab.root, tab.focusedLeafId)) {
+      tab.focusedLeafId = splitLeaf(tab, "", sessionId, "row", true);
+      render();
+      opts.onOpenSessionsChange?.();
+      return;
+    }
+    const target = findLeaf(tab.root, tab.focusedLeafId)!;
+    if (!target.sessionId) {
+      target.sessionId = sessionId;
+      target.draft = null;
+    } else {
+      tab.focusedLeafId = splitLeaf(tab, target.id, sessionId, "row", true);
+    }
+    render();
+    opts.onOpenSessionsChange?.();
+  }
+
   function openDraft(seed?: Partial<Draft>): void {
     const tab = activeTab(layout);
     const draft = (): Draft => ({ command: "", cwd: "", name: "", ...seed });
@@ -389,9 +423,15 @@ export function createMultiView(opts: MultiViewOptions): MultiView {
       return;
     }
     const target = findLeaf(tab.root, tab.focusedLeafId)!;
-    if (!target.sessionId && !target.draft) {
-      // An already-empty pane becomes the draft in place.
+    if (!target.sessionId) {
+      // Empty = no session, not `!draft` (#72): the mounted form auto-syncs
+      // picked defaults into `draft` once ready, so that's never reliably null.
       target.draft = draft();
+      const stale = draftForms.get(target.id);
+      if (stale) {
+        stale.destroy();
+        draftForms.delete(target.id);
+      }
     } else {
       // Split a fresh draft beside the focused pane.
       tab.focusedLeafId = splitLeaf(tab, target.id, null, "row", true);
@@ -661,6 +701,16 @@ export function createMultiView(opts: MultiViewOptions): MultiView {
         const dragged = findLeaf(tab.root, self)!;
         [dragged.sessionId, target.sessionId] = [target.sessionId, dragged.sessionId];
         [dragged.draft, target.draft] = [target.draft, dragged.draft];
+        // The leaf data moved but each pane's mounted form is still keyed to
+        // its old leaf (#73) — tear both down like openDraft's reuse case
+        // (#72) so render() remounts fresh forms seeded from the swapped data.
+        for (const id of [dragged.id, target.id]) {
+          const stale = draftForms.get(id);
+          if (stale) {
+            stale.destroy();
+            draftForms.delete(id);
+          }
+        }
         tab.focusedLeafId = target.id;
       } else if (sessionId) {
         const loc = locateSession(layout, sessionId);
@@ -693,6 +743,7 @@ export function createMultiView(opts: MultiViewOptions): MultiView {
   return {
     el,
     openSession,
+    openSessionBeside,
     openDraft,
     closeSession,
     openSessions: () => openSessions(layout),

web/src/projectPicker.test.ts

@@ -34,13 +34,13 @@ function stubFetch(info: unknown, projects: Project[]): void {
   );
 }
 
-function rowPaths(form: HTMLFormElement): string[] {
-  return [...form.querySelectorAll<HTMLButtonElement>(".project-row:not(.project-other)")].map(
-    (r) => r.dataset.cwd ?? "",
+function boxPaths(form: HTMLFormElement): string[] {
+  return [...form.querySelectorAll<HTMLButtonElement>(".project-box")].map(
+    (b) => b.dataset.cwd ?? "",
   );
 }
 
-describe("spawnForm project picker", () => {
+describe("spawnForm project picker (#95: boxes, full paths, mains only)", () => {
   let handle: SpawnFormHandle | null = null;
 
   beforeEach(() => {
@@ -65,7 +65,7 @@ describe("spawnForm project picker", () => {
     return handle;
   }
 
-  it("renders one row per project, fresh before stale", async () => {
+  it("renders one box per project, fresh before stale", async () => {
     const fresh = project({ name: "fresh", path: "/home/user/fresh", last_activity: NOW });
     const stale = project({
       name: "stale",
@@ -73,40 +73,56 @@ describe("spawnForm project picker", () => {
       last_activity: "2026-01-01T00:00:00Z",
     });
     const form = (await mount([stale, fresh])).el;
-    expect(rowPaths(form)).toEqual(["/home/user/fresh", "/home/user/stale"]);
-    const rows = [...form.querySelectorAll<HTMLButtonElement>(".project-row")];
-    expect(rows[1].classList.contains("is-stale")).toBe(true);
-    expect(rows[0].classList.contains("is-stale")).toBe(false);
+    expect(boxPaths(form)).toEqual(["/home/user/fresh", "/home/user/stale"]);
+    const boxes = [...form.querySelectorAll<HTMLButtonElement>(".project-box")];
+    expect(boxes[1].classList.contains("is-stale")).toBe(true);
+    expect(boxes[0].classList.contains("is-stale")).toBe(false);
   });
 
-  it("nests worktrees under their base repository", async () => {
+  it("shows the name as the primary line and the full path unabbreviated", async () => {
+    const p = project({ name: "nixos-config", path: "/home/user/tea/nixos-config" });
+    const form = (await mount([p])).el;
+    const box = form.querySelector<HTMLButtonElement>(".project-box")!;
+    expect(box.querySelector(".project-name")!.textContent).toBe("nixos-config");
+    // Not `~/t/nixos-config`: the abbreviation hid what distinguishes two
+    // projects sharing a basename (#95).
+    expect(box.querySelector(".project-path")!.textContent).toBe("/home/user/tea/nixos-config");
+  });
+
+  it("lists only main checkouts as boxes — worktrees belong to step two", async () => {
     const main = project({ name: "maestro", path: "/home/user/maestro" });
     const wt = project({
       name: "wt",
-      path: "/elsewhere/wt",
+      path: "/home/user/maestro/worktrees/wt",
       is_worktree: true,
       base_repo: main.path,
     });
     const form = (await mount([wt, main])).el;
-    expect(rowPaths(form)).toEqual(["/home/user/maestro", "/elsewhere/wt"]);
-    const [mainRow, wtRow] = [
-      ...form.querySelectorAll(".project-row:not(.project-other)"),
-    ];
-    expect(wtRow.classList.contains("is-worktree")).toBe(true);
-    expect(mainRow.classList.contains("is-worktree")).toBe(false);
+    expect(boxPaths(form)).toEqual(["/home/user/maestro"]);
+    expect(form.querySelector(".project-box.is-worktree")).toBeNull();
   });
 
-  it("filters rows as the operator types", async () => {
+  it("filters boxes as the operator types, keeping a repo its worktree matched", async () => {
     const a = project({ name: "maestro", path: "/home/user/maestro" });
     const b = project({ name: "tea", path: "/home/user/work/tea" });
-    const form = (await mount([a, b])).el;
+    const wt = project({
+      name: "bulgarians",
+      path: "/home/user/maestro/worktrees/bulgarians",
+      is_worktree: true,
+      base_repo: a.path,
+    });
+    const form = (await mount([a, b, wt])).el;
     const filter = form.querySelector<HTMLInputElement>(".project-filter")!;
     filter.value = "tea";
     filter.dispatchEvent(new Event("input"));
-    expect(rowPaths(form)).toEqual(["/home/user/work/tea"]);
+    expect(boxPaths(form)).toEqual(["/home/user/work/tea"]);
+    // A query that only matches a worktree still surfaces its repository box.
+    filter.value = "bulgarians";
+    filter.dispatchEvent(new Event("input"));
+    expect(boxPaths(form)).toEqual(["/home/user/maestro"]);
     filter.value = "zzz";
     filter.dispatchEvent(new Event("input"));
-    expect(rowPaths(form)).toEqual([]);
+    expect(boxPaths(form)).toEqual([]);
     expect(form.querySelector(".picker-empty")).toBeTruthy();
   });
 
@@ -135,17 +151,17 @@ describe("spawnForm project picker", () => {
     for (let i = 0; i < 20; i++) await Promise.resolve();
     onChange.mockClear();
 
-    const row = form.querySelector<HTMLButtonElement>(".project-row")!;
-    row.click();
+    const box = form.querySelector<HTMLButtonElement>(".project-box")!;
+    box.click();
 
     const values = form.querySelector<HTMLInputElement>("input[name=name]")!.value;
     const last = onChange.mock.lastCall![0];
     expect(last.cwd).toBe("/home/user/maestro");
     expect(last.command).toBe("claude");
     expect(values).toBeTruthy();
-    // The raw input stays hidden — the picked row is the source of truth.
+    // The raw input stays hidden — the picked box is the source of truth.
     expect((form.querySelector(".cwd-raw-wrap") as HTMLElement).hidden).toBe(true);
-    expect(row.classList.contains("is-active")).toBe(true);
+    expect(box.classList.contains("is-active")).toBe(true);
   });
 
   it("keeps an 'Other directory…' escape hatch that reveals the raw input", async () => {

web/src/routes.ts

@@ -13,6 +13,7 @@ export const PROJECTS = "/api/projects";
 export const GITROOT = "/api/gitroot";
 export const NAMES = "/api/names";
 export const BRANCHES = "/api/branches";
+export const WORKTREES = "/api/worktrees";
 export const EVENTS = "/api/events";
 
 /** Name of the query parameter `DIRS` and `GITROOT` both take. */
@@ -29,6 +30,11 @@ export function attach(id: Uuid): string {
   return `${API_PREFIX}/attach/${encodeURIComponent(id)}`;
 }
 
+/** `DELETE /api/worktrees/:id` — reclaim one retained worktree (#80). */
+export function worktree(id: Uuid): string {
+  return `${WORKTREES}/${encodeURIComponent(id)}`;
+}
+
 /** Append the `path` query parameter `DIRS` and `GITROOT` accept. */
 export function withPathQuery(route: string, value: string): string {
   return `${route}?${PATH_QUERY}=${encodeURIComponent(value)}`;

web/src/spawnForm.test.ts

@@ -9,6 +9,7 @@ const base: SpawnFormValues = {
   worktreeEnabled: false,
   worktreeBranch: "",
   worktreeBranchMode: "new",
+  worktreeBranchEdited: false,
 };
 
 describe("buildSpawnRequest", () => {
@@ -37,7 +38,6 @@ describe("buildSpawnRequest", () => {
         worktree: {
           base_repo: "/home/user/project",
           branch: "feat/foo",
-          cleanup_on_kill: true,
           create_branch: true,
         },
       },
@@ -62,7 +62,6 @@ describe("buildSpawnRequest", () => {
         worktree: {
           base_repo: "/home/user/project",
           branch: "spawn-v2",
-          cleanup_on_kill: true,
           create_branch: false,
         },
       },

web/src/spawnForm.ts

@@ -9,8 +9,8 @@ import {
 } from "./api.js";
 import { attachDirAutocomplete } from "./dirAutocomplete.js";
 import { filterProjects, groupProjects, isStale, sortProjects } from "./projectList.js";
+import type { ProjectGroup } from "./projectList.js";
 import type { BranchInfo, CreateSessionRequest, Project, Session, SpawnPreset } from "./types.js";
-import { abbreviateCwd, abbreviateFolderName } from "./types.js";
 
 /** Where a worktree's branch comes from: freshly created (default) or picked
  * from the repository's existing branches (#61). */
@@ -25,6 +25,10 @@ export interface SpawnFormSeed {
   name?: string;
   worktreeEnabled?: boolean;
   worktreeBranch?: string;
+  /** Whether the operator typed the branch themselves, rather than it having
+   *  been auto-synced from the session name. Carried separately because the
+   *  value alone cannot distinguish the two. */
+  worktreeBranchEdited?: boolean;
   worktreeBranchMode?: WorktreeBranchMode;
   cwdRawVisible?: boolean;
 }
@@ -37,6 +41,7 @@ export interface SpawnFormValues {
   name: string;
   worktreeEnabled: boolean;
   worktreeBranch: string;
+  worktreeBranchEdited: boolean;
   /** "new" creates the branch; "existing" checks out a picked one (#61). */
   worktreeBranchMode: WorktreeBranchMode;
   /** Whether the cwd lives in the raw text input (vs a picked recent row). */
@@ -70,9 +75,6 @@ export function buildSpawnRequest(
     req.worktree = {
       base_repo: baseRepo,
       branch,
-      // The daemon always cleans up, guarded against unsaved work (#56);
-      // the wire field stays for older daemons.
-      cleanup_on_kill: true,
       // Existing-mode picks must check out as-is; the daemon creates
       // anything else with `worktree add -b` (#56/#61).
       create_branch: mode !== "existing",
@@ -83,14 +85,20 @@ export function buildSpawnRequest(
 }
 
 /** Built-ins used when the daemon's `/api/info` presets can't be fetched
- * (older daemon, transient error). Mirrors `maestro_config::builtin_presets`. */
-const FALLBACK_PRESETS: SpawnPreset[] = [
+ * (older daemon, transient error). Mirrors `maestro_config::builtin_presets`.
+ * Exported for the fast-forward spawn's preset fallback (#67). */
+export const FALLBACK_PRESETS: SpawnPreset[] = [
   { id: "claude", label: "Claude", command: "claude" },
   { id: "opencode", label: "opencode", command: "opencode" },
   { id: "zsh", label: "Shell", command: "zsh" },
   { id: "custom", label: "Custom…", command: "" },
 ];
 
+/** Quiet period after raw-path typing before `/api/gitroot` fires (#74).
+ * Must stay equal to `GITROOT_PROBE_DEBOUNCE_MS` in
+ * crates/maestro-tui/src/draft.rs so both clients debounce alike. */
+const GITROOT_PROBE_DEBOUNCE_MS = 250;
+
 export interface SpawnFormHandle {
   el: HTMLFormElement;
   /** Remove global listeners (dir autocomplete) — call when unmounting. */
@@ -122,15 +130,20 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
              placeholder="bash -l" autocomplete="off" />
     </div>
     <div class="field">
-      <span class="field-label">Working directory</span>
+      <span class="field-label">Project</span>
       <input class="raw-input project-filter" type="text" placeholder="Filter projects…"
              autocomplete="off" />
       <div class="picker projects"></div>
+      <button type="button" class="project-other">Other directory…</button>
       <div class="raw-wrap cwd-raw-wrap" hidden>
         <input class="raw-input cwd-raw" name="cwd_raw" type="text"
                placeholder="/home/user/project" inputmode="text" autocomplete="off" />
       </div>
     </div>
+    <div class="field wt-step" hidden>
+      <span class="field-label">Worktree</span>
+      <div class="picker wt-choices"></div>
+    </div>
     <div class="field">
       <span class="field-label">Name</span>
       <div class="name-row">
@@ -139,33 +152,38 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
       </div>
     </div>
     <fieldset class="worktree">
-      <legend>
+      <button type="button" class="tree-folder-header wt-toggle" aria-expanded="false">
+        <span class="chevron">▾</span>
+        <span class="folder-name">Advanced options</span>
+        <span class="wt-summary"></span>
+      </button>
+      <div class="wt-collapsible" hidden>
         <label class="row-inline">
           <input type="checkbox" name="worktree_enabled" />
           Create git worktree
         </label>
-      </legend>
-      <p class="wt-hint" hidden></p>
-      <div class="wt-body" hidden>
-        <p class="wt-repo"></p>
-        <div class="wt-mode" role="radiogroup" aria-label="Branch source">
-          <label class="row-inline">
-            <input type="radio" name="worktree_branch_mode" value="new" />
-            New branch
+        <p class="wt-hint" hidden></p>
+        <div class="wt-body" hidden>
+          <p class="wt-repo"></p>
+          <div class="wt-mode" role="radiogroup" aria-label="Branch source">
+            <label class="row-inline">
+              <input type="radio" name="worktree_branch_mode" value="new" />
+              New branch
+            </label>
+            <label class="row-inline">
+              <input type="radio" name="worktree_branch_mode" value="existing" />
+              Existing branch
+            </label>
+          </div>
+          <label class="wt-new-wrap">
+            New branch name
+            <input name="worktree_branch" type="text" placeholder="feat/foo" autocomplete="off" />
           </label>
-          <label class="row-inline">
-            <input type="radio" name="worktree_branch_mode" value="existing" />
-            Existing branch
+          <label class="wt-exist-wrap" hidden>
+            Pick a branch
+            <select class="branch-select"></select>
           </label>
         </div>
-        <label class="wt-new-wrap">
-          Branch
-          <input name="worktree_branch" type="text" placeholder="feat/foo" autocomplete="off" />
-        </label>
-        <label class="wt-exist-wrap" hidden>
-          Branch
-          <select class="branch-select"></select>
-        </label>
       </div>
     </fieldset>
     <p class="form-error" role="alert" aria-live="polite"></p>
@@ -179,11 +197,17 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
   const errEl = form.querySelector(".form-error") as HTMLElement;
   const cmdTiles = form.querySelector(".cmd-tiles") as HTMLElement;
   const cmdRaw = form.querySelector(".cmd-raw") as HTMLInputElement;
-  const recentsEl = form.querySelector(".projects") as HTMLElement;
+  const projectsEl = form.querySelector(".projects") as HTMLElement;
   const filterInput = form.querySelector(".project-filter") as HTMLInputElement;
+  const otherBtn = form.querySelector(".project-other") as HTMLButtonElement;
+  const wtStep = form.querySelector(".wt-step") as HTMLElement;
+  const wtChoices = form.querySelector(".wt-choices") as HTMLElement;
   const cwdRawWrap = form.querySelector(".cwd-raw-wrap") as HTMLElement;
   const cwdRaw = form.querySelector(".cwd-raw") as HTMLInputElement;
   const wtEnabled = form.querySelector("input[name=worktree_enabled]") as HTMLInputElement;
+  const wtToggle = form.querySelector(".wt-toggle") as HTMLButtonElement;
+  const wtCollapsible = form.querySelector(".wt-collapsible") as HTMLElement;
+  const wtSummary = form.querySelector(".wt-summary") as HTMLElement;
   const wtHint = form.querySelector(".wt-hint") as HTMLElement;
   const wtBody = form.querySelector(".wt-body") as HTMLElement;
   const wtRepo = form.querySelector(".wt-repo") as HTMLElement;
@@ -229,6 +253,7 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
       name: nameInput.value,
       worktreeEnabled: wtEnabled.checked,
       worktreeBranch: branchValue(),
+      worktreeBranchEdited: branchEdited,
       worktreeBranchMode: branchMode,
       cwdRawVisible: !cwdRawWrap.hidden,
     });
@@ -238,7 +263,11 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
   // The worktree branch defaults to the session name — including a clone's
   // prefilled name — and tracks it on reroll/edit until the user types their
   // own branch. Only in "new" mode: an existing-branch pick is not a name.
-  let branchEdited = Boolean(prefill.worktreeBranch);
+  // True only once the operator types their own branch. It cannot be inferred
+  // from the seed: in "new" mode `emit()` publishes the auto-synced session
+  // name, so seeding from it froze the branch after any form rebuild
+  // (#67 review). `worktreeBranchEdited` is carried explicitly instead.
+  let branchEdited = Boolean(prefill.worktreeBranchEdited);
   const syncBranchToName = () => {
     if (!branchEdited && branchMode === "new") branchInput.value = nameInput.value;
   };
@@ -329,6 +358,15 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
     emit();
   }
 
+  /** Re-highlight the operator's already-picked tile after `renderCommandTiles`
+   * rebuilds the row from scratch (new tiles carry no `is-active` class) —
+   * without touching `command`, since that was already settled. */
+  function reapplyActiveTile(): void {
+    for (const tile of cmdTiles.querySelectorAll(".tile")) {
+      tile.classList.toggle("is-active", (tile as HTMLElement).dataset.id === selectedPresetId);
+    }
+  }
+
   function renderCommandTiles(): void {
     cmdTiles.replaceChildren();
     for (const p of presets) {
@@ -337,13 +375,23 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
       tile.className = "tile";
       tile.dataset.id = p.id;
       tile.innerHTML = `<span class="tile-label">${escapeHtml(p.label)}</span>`;
-      tile.addEventListener("click", () => selectPreset(p.id));
+      tile.addEventListener("click", () => {
+        commandTouched = true;
+        selectPreset(p.id);
+      });
       cmdTiles.appendChild(tile);
     }
   }
 
+  // Set once the operator picks a tile or types a custom command — guards
+  // `applyInitialCommand()` the same way `nameTouched` guards a late name
+  // batch: a late `/api/info` resolution must never overwrite a field the
+  // operator has already touched (#76).
+  let commandTouched = false;
+
   cmdRaw.addEventListener("input", () => {
     if (selectedPresetId === "custom" || presets.find((p) => p.id === selectedPresetId)?.command === "") {
+      commandTouched = true;
       command = cmdRaw.value.trim();
       emit();
     }
@@ -359,7 +407,11 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
       if (info.presets?.length) {
         presets = info.presets;
         renderCommandTiles();
-        applyInitialCommand();
+        if (commandTouched) {
+          reapplyActiveTile();
+        } else {
+          applyInitialCommand();
+        }
       }
     })
     .catch(() => {
@@ -386,12 +438,36 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
     if (first) selectPreset(first.id, false);
   }
 
-  // ---- working-directory picker ---------------------------------------
+  // ---- working-directory picker (#95) ----------------------------------
+  // Two steps, and the TUI mirror (#96) must match these rules verbatim:
+  //  1. Step one is one box per repository (name, then full path). A worktree
+  //     is a box only when its main checkout is missing from the scan.
+  //  2. The filter keeps a repository when the query matches it or any of its
+  //     worktrees, so a worktree name still finds its box.
+  //  3. Picking a box reveals step two: "+ new", then that repository's
+  //     worktrees newest-first. "Other directory…" clears both steps.
+  //  4. "+ new" is the default selection — except on a box that is itself a
+  //     linked worktree, which defaults to that worktree.
+  //  5. "+ new" means create: cwd is the repository, create-worktree on.
+  //     An existing worktree means run in it: cwd is that worktree,
+  //     create-worktree OFF. The daemon never adopts (docs/WORKTREES.md), so
+  //     these are separate acts — #91's rule, now an explicit choice.
+  //  6. Neither step probes /api/gitroot; the scan already reports repository
+  //     membership. Only the free-text hatch pays for a probe.
+
+  /** "new" (create a worktree) or the path of an existing worktree to run in. */
+  type WorktreeChoice = "new" | string;
+
+  let discovered: Project[] = []; // daemon snapshot, daemon-sorted
+  let groups: ProjectGroup[] = []; // rebuilt on every render
+  let selectedGroup: ProjectGroup | null = null;
+  let worktreeChoice: WorktreeChoice = "new";
+
   function showRawCwd(prefillValue?: string, focus = true): void {
     cwdRawWrap.hidden = false;
     if (prefillValue != null) cwd = prefillValue;
     cwdRaw.value = cwd;
-    markActiveProject(null);
+    clearProjectSelection();
     if (focus) {
       cwdRaw.focus();
       cwdRaw.select();
@@ -405,55 +481,94 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
     cwd = cwdRaw.value.trim();
     branchCache = null;
     emit();
-    if (wtEnabled.checked) probeGitRoot();
+    if (wtEnabled.checked) scheduleGitRootProbe();
   });
 
-  function markActiveProject(activeCwd: string | null): void {
-    for (const row of recentsEl.querySelectorAll(".project-row")) {
-      row.classList.toggle(
-        "is-active",
-        (row as HTMLElement).dataset.cwd === activeCwd,
-      );
+  /** Every worktree of a group, including the group's own box when the scan
+   * found no main checkout to nest it under. */
+  function worktreesOf(group: ProjectGroup): Project[] {
+    return [group.main, ...group.worktrees].filter((p) => p.is_worktree);
+  }
+
+  function markActiveBox(): void {
+    const active = selectedGroup?.main.path ?? null;
+    for (const box of projectsEl.querySelectorAll(".project-box")) {
+      box.classList.toggle("is-active", (box as HTMLElement).dataset.cwd === active);
     }
   }
 
-  function selectProject(project: Project): void {
-    cwd = project.path;
+  function markActiveChoice(): void {
+    for (const btn of wtChoices.querySelectorAll(".wt-choice")) {
+      const el = btn as HTMLElement;
+      const value = el.dataset.kind === "new" ? "new" : (el.dataset.cwd ?? "");
+      el.classList.toggle("is-active", value === worktreeChoice);
+    }
+  }
+
+  function clearProjectSelection(): void {
+    selectedGroup = null;
+    worktreeChoice = "new";
+    wtChoices.replaceChildren();
+    wtStep.hidden = true;
+    markActiveBox();
+  }
+
+  function selectProject(group: ProjectGroup): void {
+    selectedGroup = group;
     cwdRawWrap.hidden = true;
-    markActiveProject(project.path);
-    // The scan already knows this directory is inside a repo (#61): the
-    // toggle defaults back on and no /api/gitroot round trip is needed.
-    wtEnabled.checked = true;
-    applyProjectRepo(project.base_repo ?? project.path);
+    renderWorktreeChoices(group);
+    markActiveBox();
+    // Rule 4: a box that is itself a linked worktree defaults to running there.
+    applyWorktreeChoice(group.main.is_worktree ? group.main.path : "new");
+  }
+
+  function applyWorktreeChoice(choice: WorktreeChoice): void {
+    const group = selectedGroup;
+    if (!group) return;
+    const target =
+      choice === "new" ? group.main : worktreesOf(group).find((p) => p.path === choice);
+    if (!target) return;
+    worktreeChoice = choice;
+    cwd = target.path;
+    branchCache = null;
+    markActiveChoice();
+    if (choice === "new") {
+      wtEnabled.checked = true;
+      updateWtSummary();
+      applyProjectRepo(group.main.base_repo ?? group.main.path);
+    } else {
+      wtEnabled.checked = false;
+      updateWtSummary();
+      inferredBaseRepo = null;
+      wtBody.hidden = true;
+      wtHint.hidden = true;
+    }
     emit();
-    // Picking a project pre-selects the command it was last used with.
-    const match = presets.find((p) => p.command === project.last_command && p.command !== "");
+    // The chosen directory pre-selects the command it was last used with.
+    const match = presets.find((p) => p.command === target.last_command && p.command !== "");
     if (match) selectPreset(match.id);
   }
 
-  let discovered: Project[] = []; // daemon snapshot, daemon-sorted
-
   function renderProjects(): void {
-    recentsEl.replaceChildren();
-    const sorted = sortProjects(filterProjects(discovered, filterInput.value), new Date());
-    for (const group of groupProjects(sorted)) {
-      recentsEl.appendChild(projectRow(group.main));
-      for (const wt of group.worktrees) recentsEl.appendChild(projectRow(wt));
-    }
-    if (discovered.length > 0 && sorted.length === 0) {
+    projectsEl.replaceChildren();
+    groups = groupProjects(sortProjects(discovered, new Date()));
+    const query = filterInput.value;
+    const visible = groups.filter((g) => filterProjects([g.main, ...g.worktrees], query).length > 0);
+    for (const group of visible) projectsEl.appendChild(projectBox(group));
+    if (discovered.length > 0 && visible.length === 0) {
       const empty = document.createElement("p");
       empty.className = "picker-empty";
       empty.textContent = "No projects match.";
-      recentsEl.appendChild(empty);
+      projectsEl.appendChild(empty);
     }
-    recentsEl.appendChild(otherDirRow());
-    markActiveProject(cwdRawWrap.hidden ? cwd : null);
+    markActiveBox();
   }
 
   filterInput.addEventListener("input", renderProjects);
+  otherBtn.addEventListener("click", () => showRawCwd(cwd || homeDir));
 
   async function loadProjects(): Promise<void> {
-    recentsEl.replaceChildren(loadingRow());
+    projectsEl.replaceChildren(loadingRow());
     try {
       discovered = await fetchProjects();
     } catch {
@@ -464,12 +579,13 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
     if (seedCwd) {
       // A seed sets the directory verbatim, regardless of what the scan found.
       // `cwdRawVisible === false` marks a draft restore whose cwd came from a
-      // picked row: keep the picker and don't steal focus. Otherwise land
+      // picked box: keep the picker and don't steal focus. Otherwise land
       // focused in the raw input (clone / no-match flows).
       if (prefill.cwdRawVisible === false) {
         cwd = seedCwd;
         cwdRaw.value = seedCwd;
-        markActiveProject(cwd);
+        // Restoring must not touch the worktree toggle — the seed carries it.
+        if (!restoreSelection(seedCwd)) clearProjectSelection();
       } else {
         showRawCwd(seedCwd, false);
       }
@@ -486,34 +602,66 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
     emit();
   }
 
-  function projectRow(project: Project): HTMLElement {
-    const row = document.createElement("button");
-    row.type = "button";
-    row.className = `project-row${project.is_worktree ? " is-worktree" : ""}${
-      isStale(project, new Date()) ? " is-stale" : ""
-    }`;
-    row.dataset.cwd = project.path;
-    // Abbreviate exactly like the sidebar: home → `~`, then collapse leading
-    // segments to initials (`~/g/n/maestro`). The full path stays in the tooltip
-    // and `dataset.cwd` (what's actually submitted).
-    const display = abbreviateFolderName(abbreviateCwd(project.path, homeDir));
-    row.innerHTML = `
-      <span class="project-info">
-        <span class="project-name">${escapeHtml(project.name)}</span>
-        <span class="recent-dir" title="${escapeHtml(project.path)}">${display}</span>
-      </span>
-      <span class="recent-cmd">${escapeHtml(project.last_command ?? "")}</span>`;
-    row.addEventListener("click", () => selectProject(project));
-    return row;
+  /** Put the two steps back on a restored draft's cwd, without re-running the
+   * side effects of a fresh pick. */
+  function restoreSelection(path: string): boolean {
+    for (const group of groups) {
+      const wt = worktreesOf(group).find((p) => p.path === path);
+      const choice: WorktreeChoice | null =
+        wt ? wt.path : group.main.path === path ? "new" : null;
+      if (choice === null) continue;
+      selectedGroup = group;
+      worktreeChoice = choice;
+      renderWorktreeChoices(group);
+      markActiveChoice();
+      markActiveBox();
+      return true;
+    }
+    return false;
   }
 
-  function otherDirRow(): HTMLElement {
-    const row = document.createElement("button");
-    row.type = "button";
-    row.className = "project-row project-other";
-    row.innerHTML = `<span class="project-info"><span class="recent-dir">Other directory…</span></span>`;
-    row.addEventListener("click", () => showRawCwd(cwd || homeDir));
-    return row;
+  function projectBox(group: ProjectGroup): HTMLElement {
+    const project = group.main;
+    const box = document.createElement("button");
+    box.type = "button";
+    box.className = `project-box${isStale(project, new Date()) ? " is-stale" : ""}`;
+    box.dataset.cwd = project.path;
+    const trees = worktreesOf(group).length;
+    // The full path, not the sidebar's `~/t/n/maestro` abbreviation: it is what
+    // tells two projects sharing a basename apart (#95).
+    const meta = [trees > 0 ? `${trees} worktree${trees === 1 ? "" : "s"}` : "", project.last_command ?? ""]
+      .filter(Boolean)
+      .join(" · ");
+    box.innerHTML = `
+      <span class="project-name">${escapeHtml(project.name)}</span>
+      <span class="project-path">${escapeHtml(project.path)}</span>
+      <span class="project-meta">${escapeHtml(meta)}</span>`;
+    box.addEventListener("click", () => selectProject(group));
+    return box;
+  }
+
+  function renderWorktreeChoices(group: ProjectGroup): void {
+    wtChoices.replaceChildren();
+    wtChoices.appendChild(
+      choiceButton("new", "+ new", `new worktree of ${group.main.name}`),
+    );
+    for (const wt of worktreesOf(group)) {
+      wtChoices.appendChild(choiceButton(wt.path, wt.name, wt.path));
+    }
+    wtStep.hidden = false;
+  }
+
+  function choiceButton(choice: WorktreeChoice, label: string, sub: string): HTMLElement {
+    const btn = document.createElement("button");
+    btn.type = "button";
+    btn.className = `wt-choice${choice === "new" ? " wt-choice-new" : ""}`;
+    btn.dataset.kind = choice === "new" ? "new" : "existing";
+    if (choice !== "new") btn.dataset.cwd = choice;
+    btn.innerHTML = `
+      <span class="wt-choice-name">${escapeHtml(label)}</span>
+      <span class="wt-choice-sub">${escapeHtml(sub)}</span>`;
+    btn.addEventListener("click", () => applyWorktreeChoice(choice));
+    return btn;
   }
 
   function loadingRow(): HTMLElement {
@@ -523,6 +671,18 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
     return p;
   }
 
+  // ---- worktree: disclosure (#93), reuses the sidebar's folder-header ---
+  let advancedCollapsed = true;
+  function setAdvancedCollapsed(collapsed: boolean): void {
+    advancedCollapsed = collapsed;
+    wtToggle.setAttribute("aria-expanded", String(!collapsed));
+    wtCollapsible.hidden = collapsed;
+  }
+  function updateWtSummary(): void {
+    wtSummary.textContent = wtEnabled.checked ? "creates a worktree" : "no worktree";
+  }
+  wtToggle.addEventListener("click", () => setAdvancedCollapsed(!advancedCollapsed));
+
   // ---- worktree (branch-only; base_repo inferred via scan or /gitroot) --
   // The project scan already reports repo membership, so a picked project
   // resolves its base repo locally (#61); only the free-text escape hatch
@@ -539,6 +699,16 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
   /** Decide how the worktree section describes the current target. Called
    * once the initial load has settled `cwd`. */
   function resolveBaseRepo(): void {
+    // Nothing to resolve when the operator turned the worktree off — the
+    // section would otherwise rebuild expanded under an unchecked box, and
+    // fire a `/api/gitroot` probe for a worktree nobody asked for
+    // (#67 review).
+    if (!wtEnabled.checked) {
+      wtBody.hidden = true;
+      wtHint.hidden = true;
+      inferredBaseRepo = null;
+      return;
+    }
     if (!cwd) {
       inferredBaseRepo = null;
       wtBody.hidden = true;
@@ -551,7 +721,20 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
       applyProjectRepo(project.base_repo ?? project.path);
       return;
     }
-    void probeGitRoot();
+    scheduleGitRootProbe();
+  }
+
+  // Every keystroke resets this timer, so a burst of typing issues one
+  // request once the operator pauses. `probeToken` inside probeGitRoot still
+  // owns ordering: a scheduled probe that fires after a newer one started
+  // loses the token race and is dropped.
+  let probeTimer: number | undefined;
+  function scheduleGitRootProbe(): void {
+    window.clearTimeout(probeTimer);
+    probeTimer = window.setTimeout(() => {
+      probeTimer = undefined;
+      void probeGitRoot();
+    }, GITROOT_PROBE_DEBOUNCE_MS);
   }
 
   async function probeGitRoot(): Promise<void> {
@@ -580,6 +763,7 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
       // Publish the untick too, or the next render seeds the box checked with
       // no inferred repo and submitting fails.
       wtEnabled.checked = false;
+      updateWtSummary();
       emit();
       wtBody.hidden = true;
       wtHint.hidden = false;
@@ -633,11 +817,14 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
       return;
     }
     for (const b of branches) {
-      // A branch another worktree holds stays visible but unpickable — git
-      // would refuse to check it out twice; the path says who holds it.
-      const o = opt(b.worktree ? `${b.name} — held by ${b.worktree}` : b.name, b.name);
-      o.disabled = Boolean(b.worktree);
-      o.title = b.worktree ?? "";
+      // A branch that is already checked out anywhere stays visible but
+      // unpickable — git refuses a second checkout. That includes the main
+      // checkout's own HEAD, which is commonly `main` and would otherwise be
+      // the default pick, making every existing-branch spawn fail (#54 review).
+      const held = b.worktree ?? (b.is_head ? "the main checkout" : null);
+      const o = opt(held ? `${b.name} — held by ${held}` : b.name, b.name);
+      o.disabled = held !== null;
+      o.title = held ?? "";
       branchSelect.appendChild(o);
     }
   }
@@ -650,6 +837,7 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
   branchSelect.addEventListener("change", () => emit());
 
   wtEnabled.addEventListener("change", () => {
+    updateWtSummary();
     emit();
     if (wtEnabled.checked) {
       resolveBaseRepo();
@@ -663,6 +851,7 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
   // The toggle defaults ON (#61): the operator almost always wants a
   // worktree, and every non-repo target unticks it via the gitroot probe.
   wtEnabled.checked = prefill.worktreeEnabled ?? true;
+  updateWtSummary();
   if (prefill.worktreeBranch) branchInput.value = prefill.worktreeBranch;
   setBranchMode(branchMode);
 
@@ -684,6 +873,7 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
         name: nameInput.value,
         worktreeEnabled: wtEnabled.checked,
         worktreeBranch: branchValue(),
+        worktreeBranchEdited: branchEdited,
         worktreeBranchMode: branchMode,
       },
       inferredBaseRepo,
@@ -708,6 +898,7 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
     el: form,
     destroy() {
       destroyed = true;
+      window.clearTimeout(probeTimer);
       autocomplete.destroy();
       form.remove();
     },

web/src/spawnFormPreset.test.ts

@@ -0,0 +1,124 @@
+// @vitest-environment happy-dom
+import { afterEach, describe, expect, it, vi } from "vitest";
+
+import { createSpawnForm, type SpawnFormHandle, type SpawnFormValues } from "./spawnForm.js";
+
+/** Stubs fetch so `/api/info` only resolves once `resolveInfo()` is called —
+ * everything else (names, projects, gitroot) answers immediately with an
+ * empty/default body. Lets a test pick a preset (or type a custom command)
+ * mid-flight, then observe what the late `/api/info` resolution does to it. */
+function stubDeferredInfo(): { resolveInfo: () => void } {
+  let releaseInfo: () => void = () => {};
+  const infoGate = new Promise<void>((resolve) => {
+    releaseInfo = resolve;
+  });
+  vi.stubGlobal(
+    "fetch",
+    vi.fn(async (input: RequestInfo | URL) => {
+      const url = String(input);
+      if (url.includes("/api/info")) {
+        await infoGate;
+        return new Response(
+          JSON.stringify({
+            hostname: "h",
+            version: "0",
+            home_dir: "/home/user",
+            presets: [
+              { id: "claude", label: "Claude", command: "claude" },
+              { id: "fish", label: "Fish", command: "fish" },
+              { id: "custom", label: "Custom…", command: "" },
+            ],
+          }),
+          { status: 200 },
+        );
+      }
+      if (url.includes("/api/names")) {
+        return new Response(JSON.stringify({ names: ["amber-fox"] }), { status: 200 });
+      }
+      return new Response(JSON.stringify([]), { status: 200 });
+    }),
+  );
+  return { resolveInfo: releaseInfo };
+}
+
+describe("spawnForm preset selection vs. late /api/info (#76)", () => {
+  let handle: SpawnFormHandle | null = null;
+
+  afterEach(() => {
+    handle?.destroy();
+    handle = null;
+    vi.unstubAllGlobals();
+  });
+
+  async function drain(): Promise<void> {
+    for (let i = 0; i < 40; i++) await Promise.resolve();
+  }
+
+  it("keeps an operator-picked tile after /api/info resolves late", async () => {
+    const { resolveInfo } = stubDeferredInfo();
+    let values: SpawnFormValues | undefined;
+    handle = createSpawnForm({ onChange: (v) => (values = v), onSuccess() {} });
+    const form = handle.el;
+    document.body.appendChild(form);
+    await drain();
+
+    // Fallback presets are up; the operator picks "zsh" before /api/info lands.
+    const zshTile = [...form.querySelectorAll<HTMLButtonElement>(".tile")].find(
+      (t) => t.dataset.id === "zsh",
+    )!;
+    zshTile.click();
+    expect(zshTile.classList.contains("is-active")).toBe(true);
+
+    // /api/info lands late with a preset list that doesn't even include "zsh".
+    resolveInfo();
+    await drain();
+
+    // The operator's pick must not be discarded back to the new list's first
+    // entry — `onChange` only starts firing once the initial load settles
+    // (`ready`), which happens right here, so this is the first place the
+    // published command is observable.
+    expect(values?.command).toBe("zsh");
+  });
+
+  it("keeps an operator-typed custom command after /api/info resolves late", async () => {
+    const { resolveInfo } = stubDeferredInfo();
+    let values: SpawnFormValues | undefined;
+    handle = createSpawnForm({ onChange: (v) => (values = v), onSuccess() {} });
+    const form = handle.el;
+    document.body.appendChild(form);
+    await drain();
+
+    const customTile = [...form.querySelectorAll<HTMLButtonElement>(".tile")].find(
+      (t) => t.dataset.id === "custom",
+    )!;
+    customTile.click();
+    const cmdRaw = form.querySelector<HTMLInputElement>(".cmd-raw")!;
+    cmdRaw.value = "htop";
+    cmdRaw.dispatchEvent(new Event("input"));
+
+    resolveInfo();
+    await drain();
+
+    expect(values?.command).toBe("htop");
+    expect(cmdRaw.value).toBe("htop");
+  });
+
+  it("still applies the real presets' first entry when the operator never touched the command", async () => {
+    const { resolveInfo } = stubDeferredInfo();
+    let values: SpawnFormValues | undefined;
+    handle = createSpawnForm({ onChange: (v) => (values = v), onSuccess() {} });
+    const form = handle.el;
+    document.body.appendChild(form);
+    await drain();
+
+    resolveInfo();
+    await drain();
+
+    // Untouched: the refined preset list is still free to settle the command.
+    expect(values?.command).toBe("claude");
+    const fishTile = [...form.querySelectorAll<HTMLButtonElement>(".tile")].find(
+      (t) => t.dataset.id === "fish",
+    );
+    expect(fishTile).toBeDefined();
+  });
+});

web/src/spawnFormProbe.test.ts

@@ -0,0 +1,148 @@
+// @vitest-environment happy-dom
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+
+import { createSpawnForm, type SpawnFormHandle } from "./spawnForm.js";
+
+/** Debounce window under test — must equal GITROOT_PROBE_DEBOUNCE_MS in
+ * spawnForm.ts (#74). */
+const DEBOUNCE_MS = 250;
+
+const PROJECTS = [
+  { path: "/home/user/maestro", name: "maestro", last_activity: "2026-08-20T10:00:00Z" },
+];
+
+/** Stub the fetches the form makes. Gitroot responses for a given path can be
+ * held until `releaseGitRoot(path)` is called, so tests can land answers out
+ * of order. */
+function stubFetch(opts?: { holdGitRootFor?: string[] }): {
+  urls: string[];
+  gitRootCalls: string[];
+  releaseGitRoot: (path: string) => void;
+} {
+  const urls: string[] = [];
+  const gitRootCalls: string[] = [];
+  const releases = new Map<string, () => void>();
+  const held = new Map<string, Promise<void>>();
+  vi.stubGlobal(
+    "fetch",
+    vi.fn(async (input: RequestInfo | URL) => {
+      const url = String(input);
+      urls.push(url);
+      if (url.includes("/api/dirs")) {
+        return new Response(JSON.stringify({ entries: [] }), { status: 200 });
+      }
+      if (url.includes("/api/gitroot")) {
+        const path = new URL(url, "http://localhost").searchParams.get("path") ?? "";
+        gitRootCalls.push(path);
+        if (opts?.holdGitRootFor?.includes(path)) {
+          let release!: () => void;
+          held.set(
+            path,
+            new Promise<void>((r) => {
+              release = r;
+            }),
+          );
+          releases.set(path, release);
+        }
+        await held.get(path);
+        return new Response(JSON.stringify({ root: path }), { status: 200 });
+      }
+      if (url.includes("/api/names")) {
+        return new Response(JSON.stringify({ names: ["amber-fox"] }), { status: 200 });
+      }
+      if (url.includes("/api/projects")) {
+        return new Response(JSON.stringify(PROJECTS), { status: 200 });
+      }
+      return new Response(
+        JSON.stringify({ hostname: "h", version: "0", home_dir: "/home/user", presets: [] }),
+        { status: 200 },
+      );
+    }),
+  );
+  return {
+    urls,
+    gitRootCalls,
+    releaseGitRoot: (path: string) => releases.get(path)?.(),
+  };
+}
+
+describe("spawnForm gitroot probe debounce (#74)", () => {
+  let handle: SpawnFormHandle | null = null;
+
+  beforeEach(() => {
+    vi.useFakeTimers();
+  });
+
+  afterEach(() => {
+    handle?.destroy();
+    handle = null;
+    vi.unstubAllGlobals();
+    vi.useRealTimers();
+  });
+
+  async function mount(opts?: Parameters<typeof stubFetch>[0]) {
+    const stub = stubFetch(opts);
+    handle = createSpawnForm({ onSuccess() {} });
+    document.body.appendChild(handle.el);
+    for (let i = 0; i < 40; i++) await Promise.resolve();
+    return { form: handle.el, stub };
+  }
+
+  const drain = async () => {
+    for (let i = 0; i < 40; i++) await Promise.resolve();
+  };
+
+  function typeRaw(form: HTMLFormElement, value: string): void {
+    const raw = form.querySelector<HTMLInputElement>("input[name=cwd_raw]")!;
+    raw.value = value;
+    raw.dispatchEvent(new Event("input"));
+  }
+
+  it("a keystroke burst fires exactly one probe after the quiet period", async () => {
+    const { form, stub } = await mount();
+
+    form.querySelector<HTMLElement>(".project-other")!.click();
+    // Burst: every keystroke reschedules; nothing may hit /api/gitroot yet.
+    for (let i = 1; i <= "/opt/somewhere".length; i++) {
+      typeRaw(form, "/opt/somewhere".slice(0, i));
+      await drain();
+      expect(stub.gitRootCalls).toEqual([]);
+    }
+
+    await vi.advanceTimersByTimeAsync(DEBOUNCE_MS);
+    await drain();
+
+    expect(stub.gitRootCalls).toEqual(["/opt/somewhere"]);
+    expect(stub.urls.filter((u) => u.includes("/api/gitroot")).length).toBe(1);
+  });
+
+  it("a stale probe answer cannot overwrite a newer input", async () => {
+    const { form, stub } = await mount({ holdGitRootFor: ["/repo/old"] });
+
+    form.querySelector<HTMLElement>(".project-other")!.click();
+
+    // Probe for the old target, held in flight.
+    typeRaw(form, "/repo/old");
+    await vi.advanceTimersByTimeAsync(DEBOUNCE_MS);
+
+    // Newer target supersedes it and answers immediately.
+    typeRaw(form, "/repo/new");
+    await vi.advanceTimersByTimeAsync(DEBOUNCE_MS);
+    await drain();
+
+    expect(stub.gitRootCalls).toEqual(["/repo/old", "/repo/new"]);
+    expect(form.querySelector<HTMLElement>(".wt-repo")!.textContent).toContain("/repo/new");
+    expect(
+      form.querySelector<HTMLInputElement>("input[name=worktree_enabled]")!.checked,
+    ).toBe(true);
+
+    // The late answer to the old target lands last but must lose.
+    stub.releaseGitRoot("/repo/old");
+    await drain();
+
+    expect(form.querySelector<HTMLElement>(".wt-repo")!.textContent).toContain("/repo/new");
+    expect(
+      form.querySelector<HTMLInputElement>("input[name=worktree_enabled]")!.checked,
+    ).toBe(true);
+  });
+});

web/src/spawnFormWorktree.test.ts

@@ -18,6 +18,7 @@ const BRANCHES = [
  * its branch list is still in flight. */
 function stubFetch(opts?: {
   gateBranches?: (release: () => void) => void;
+  projects?: unknown[];
 }): string[] {
   const urls: string[] = [];
   const gated = new Promise<void>((resolve) => {
@@ -37,7 +38,7 @@ function stubFetch(opts?: {
         return new Response(JSON.stringify(BRANCHES), { status: 200 });
       }
       if (url.includes("/api/projects")) {
-        return new Response(JSON.stringify(PROJECTS), { status: 200 });
+        return new Response(JSON.stringify(opts?.projects ?? PROJECTS), { status: 200 });
       }
       return new Response(
         JSON.stringify({ hostname: "h", version: "0", home_dir: "/home/user", presets: [] }),
@@ -79,10 +80,10 @@ describe("spawnForm worktree defaults and branch picker (#61)", () => {
   };
 
   function pickProject(form: HTMLFormElement): void {
-    form.querySelector<HTMLButtonElement>(".project-row.project-other")!.click();
+    form.querySelector<HTMLButtonElement>(".project-other")!.click();
     form
-      .querySelectorAll<HTMLButtonElement>(".project-row")
-      .forEach((row) => row.dataset.cwd === "/home/user/maestro" && row.click());
+      .querySelectorAll<HTMLButtonElement>(".project-box")
+      .forEach((box) => box.dataset.cwd === "/home/user/maestro" && box.click());
   }
 
   it("defaults the worktree toggle on for a picked project with no gitroot probe", async () => {
@@ -100,14 +101,44 @@ describe("spawnForm worktree defaults and branch picker (#61)", () => {
     );
   });
 
+  it("defaults the worktree toggle off for a row that is itself a worktree (#91)", async () => {
+    urls = stubFetch({
+      projects: [
+        {
+          path: "/home/user/wt-91",
+          name: "wt-91",
+          is_worktree: true,
+          base_repo: "/home/user/maestro",
+          last_activity: "2026-08-20T10:00:00Z",
+        },
+      ],
+    });
+    handle = createSpawnForm({ onSuccess() {} });
+    document.body.appendChild(handle.el);
+    for (let i = 0; i < 40; i++) await Promise.resolve();
+
+    handle.el
+      .querySelectorAll<HTMLButtonElement>(".project-box")
+      .forEach((box) => box.dataset.cwd === "/home/user/wt-91" && box.click());
+    await drain();
+
+    expect(handle.el.querySelector<HTMLInputElement>("input[name=worktree_enabled]")!.checked).toBe(
+      false,
+    );
+    expect(urls.some((u) => u.includes("/api/gitroot"))).toBe(false);
+    expect(handle.el.querySelector<HTMLElement>(".wt-body")!.hidden).toBe(true);
+  });
+
   it("still probes the gitroot for a free-text directory", async () => {
     const form = await mount();
 
-    // Escape hatch: switch to a free-text dir; only now does /api/gitroot fire.
-    form.querySelector<HTMLElement>(".project-row.project-other")!.click();
+    // Escape hatch: switch to a free-text dir; only now does /api/gitroot
+    // fire — debounced, so the quiet period must elapse first (#74).
+    form.querySelector<HTMLElement>(".project-other")!.click();
     const raw = form.querySelector<HTMLInputElement>("input[name=cwd_raw]")!;
     raw.value = "/opt/somewhere";
     raw.dispatchEvent(new Event("input"));
+    await vi.advanceTimersByTimeAsync(250);
     await drain();
 
     expect(urls.some((u) => u.includes("/api/gitroot"))).toBe(true);
@@ -149,6 +180,74 @@ describe("spawnForm worktree defaults and branch picker (#61)", () => {
     expect(modes.at(-1)).toBe("existing");
   });
 
+  it("labels the new-branch input and existing-branch picker distinctly (#94)", async () => {
+    const form = await mount();
+    pickProject(form);
+    await drain();
+
+    const newLabel = form.querySelector<HTMLElement>(".wt-new-wrap")!.textContent!.trim();
+    const existLabel = form.querySelector<HTMLElement>(".wt-exist-wrap")!.textContent!.trim();
+
+    expect(newLabel).not.toBe("Branch");
+    expect(existLabel).not.toBe("Branch");
+    expect(newLabel).not.toBe(existLabel);
+    expect(newLabel).toMatch(/name/i);
+    expect(existLabel).toMatch(/pick|choose|select/i);
+  });
+
+  it("collapses the advanced (worktree) section by default (#93)", async () => {
+    const form = await mount();
+    const toggle = form.querySelector<HTMLButtonElement>(".wt-toggle")!;
+    expect(toggle.getAttribute("aria-expanded")).toBe("false");
+    expect(form.querySelector<HTMLElement>(".wt-collapsible")!.hidden).toBe(true);
+  });
+
+  it("states in the collapsed header that a worktree will be created by default (#93)", async () => {
+    const form = await mount();
+    expect(form.querySelector<HTMLElement>(".wt-summary")!.textContent).toMatch(/creates? a worktree/i);
+  });
+
+  it("states in the collapsed header that no worktree will be created for a worktree row (#91, #93)", async () => {
+    urls = stubFetch({
+      projects: [
+        {
+          path: "/home/user/wt-91",
+          name: "wt-91",
+          is_worktree: true,
+          base_repo: "/home/user/maestro",
+          last_activity: "2026-08-20T10:00:00Z",
+        },
+      ],
+    });
+    handle = createSpawnForm({ onSuccess() {} });
+    document.body.appendChild(handle.el);
+    for (let i = 0; i < 40; i++) await Promise.resolve();
+
+    handle.el
+      .querySelectorAll<HTMLButtonElement>(".project-box")
+      .forEach((box) => box.dataset.cwd === "/home/user/wt-91" && box.click());
+    await drain();
+
+    expect(handle.el.querySelector<HTMLElement>(".wt-summary")!.textContent).toMatch(/no worktree/i);
+    // Still collapsed — picking a project must not force it open.
+    expect(handle.el.querySelector<HTMLButtonElement>(".wt-toggle")!.getAttribute("aria-expanded")).toBe(
+      "false",
+    );
+  });
+
+  it("expanding the advanced section does not reorder the fields above it (#93)", async () => {
+    const form = await mount();
+    const before = [...form.querySelectorAll(".field")];
+
+    form.querySelector<HTMLButtonElement>(".wt-toggle")!.click();
+
+    expect(form.querySelector<HTMLButtonElement>(".wt-toggle")!.getAttribute("aria-expanded")).toBe(
+      "true",
+    );
+    expect(form.querySelector<HTMLElement>(".wt-collapsible")!.hidden).toBe(false);
+    expect([...form.querySelectorAll(".field")]).toStrictEqual(before);
+  });
+
   it("does not repopulate a destroyed form when the branch list lands late", async () => {
     const gate: { release?: () => void } = {};
     urls = stubFetch({ gateBranches: (r) => (gate.release = r) });

web/src/styles.css

@@ -727,10 +727,8 @@ textarea {
 }
 
 /* Earlier path segments collapse to their initial; the trailing segment (the
-   one that actually names the dir) stays full. Dim the collapsed prefix. Shared
-   by the sidebar tree and the spawn dialog's recent-directory picker. */
-.folder-name .folder-stem,
-.recent-dir .folder-stem {
+   one that actually names the dir) stays full. Dim the collapsed prefix. */
+.folder-name .folder-stem {
   color: var(--faint);
 }
 
@@ -831,6 +829,13 @@ textarea {
   flex: 0 0 auto;
 }
 
+/* #83: the session row's blocked-work warning — an unforced kill will be
+   refused, and the operator should see that before pressing the button. */
+.leaf-badge.leaf-blocked {
+  color: var(--warn, #b45309);
+  border-color: var(--warn, #b45309);
+}
+
 .leaf-actions {
   position: absolute;
   right: var(--sp-1);
@@ -1208,6 +1213,9 @@ textarea {
 /* ---------- forms ---------- */
 
 .spawn-form {
+  width: 100%;
+  max-width: 60ch;
+  margin: 0 auto;
   padding: var(--sp-3);
   overflow: auto;
   display: flex;
@@ -1276,18 +1284,33 @@ textarea {
 .worktree {
   border: 1px solid var(--border);
   border-radius: var(--r-2);
-  padding: var(--sp-3);
+  padding: 0 var(--sp-3);
   margin: 0;
   display: flex;
   flex-direction: column;
-  gap: var(--sp-3);
   background: color-mix(in oklab, var(--surface-2) 50%, transparent);
 }
 
-.worktree legend {
-  padding: 0 6px;
-  color: var(--ink);
-  font-size: var(--fs-13);
+.worktree .wt-toggle {
+  margin: 0 calc(var(--sp-3) * -1);
+  padding-left: var(--sp-3);
+  width: calc(100% + var(--sp-3) * 2);
+}
+
+.wt-summary {
+  color: var(--muted);
+  font-size: var(--fs-12);
+}
+
+.wt-collapsible {
+  display: flex;
+  flex-direction: column;
+  gap: var(--sp-3);
+  padding-bottom: var(--sp-3);
+}
+
+.wt-collapsible[hidden] {
+  display: none;
 }
 
 .form-error {
@@ -1371,8 +1394,9 @@ textarea {
   color: var(--muted);
 }
 
-/* Project picker rows (#59). Worktree rows are indented under their base
-   repository; rows stale beyond 7 days are dimmed but still selectable. */
+/* Working-directory picker (#95). Two steps: a grid of project boxes, then the
+   picked project's worktree choices. Stale beyond 7 days dims but stays
+   selectable. */
 .picker {
   display: flex;
   flex-direction: column;
@@ -1387,73 +1411,155 @@ textarea {
   width: 100%;
 }
 
-.project-row {
+/* `display` from `.field`/`.raw-wrap` outranks the UA sheet's `[hidden]`, so
+   step two and the raw-cwd hatch stayed visible while hidden. */
+.wt-step[hidden],
+.raw-wrap[hidden] {
+  display: none;
+}
+
+.picker.projects {
+  display: grid;
+  grid-template-columns: repeat(auto-fill, minmax(190px, 1fr));
+  align-content: start;
+  gap: var(--sp-2);
+  max-height: 300px;
+  padding: 1px;
+}
+
+.project-box {
+  display: flex;
+  flex-direction: column;
+  gap: 2px;
+  min-width: 0;
+  padding: var(--sp-2) var(--sp-3);
+  background: var(--surface-2);
+  border: 1px solid var(--border);
+  border-radius: var(--r-2);
+  color: var(--ink);
+  font-family: inherit;
+  text-align: left;
+  cursor: pointer;
+  transition:
+    border-color var(--dur-fast) var(--ease-out),
+    background var(--dur-fast) var(--ease-out);
+}
+
+.project-box:hover {
+  border-color: var(--border-strong);
+}
+
+.project-box.is-active {
+  border-color: var(--accent);
+  background: var(--accent-tint);
+}
+
+.project-box.is-stale {
+  opacity: 0.55;
+}
+
+.project-name {
+  font-size: var(--fs-13);
+  font-weight: 600;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+/* The whole path, never abbreviated — it is what tells two projects sharing a
+   basename apart. Wraps rather than truncating so none of it is hidden. */
+.project-path {
+  font-family: var(--font-mono);
+  font-size: var(--fs-12);
+  line-height: 1.35;
+  color: var(--muted);
+  overflow-wrap: anywhere;
+}
+
+.project-meta {
+  font-family: var(--font-mono);
+  font-size: var(--fs-12);
+  color: var(--faint);
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.project-meta:empty {
+  display: none;
+}
+
+.project-other {
+  align-self: flex-start;
+  padding: 4px 0;
+  min-height: 30px;
+  background: none;
+  border: 0;
+  color: var(--muted);
+  font-family: inherit;
+  font-size: var(--fs-13);
+  font-style: italic;
+  text-align: left;
+  cursor: pointer;
+}
+
+.project-other:hover {
+  color: var(--ink);
+}
+
+/* Step two: "+ new" (create one) or an existing worktree (run in it). */
+.picker.wt-choices {
+  max-height: 200px;
+}
+
+.wt-choice {
   display: flex;
   align-items: baseline;
   justify-content: space-between;
   gap: var(--sp-3);
+  min-height: 32px;
   padding: 6px var(--sp-3);
   background: var(--surface-2);
   border: 1px solid var(--border);
   border-radius: var(--r-2);
   color: var(--ink);
   font-family: inherit;
-  cursor: pointer;
   text-align: left;
+  cursor: pointer;
   transition:
     border-color var(--dur-fast) var(--ease-out),
     background var(--dur-fast) var(--ease-out);
 }
 
-.project-row:hover {
+.wt-choice:hover {
   border-color: var(--border-strong);
 }
 
-.project-row.is-active {
+.wt-choice.is-active {
   border-color: var(--accent);
   background: var(--accent-tint);
 }
 
-.project-row.is-worktree {
-  margin-left: var(--sp-4);
-}
-
-.project-row.is-stale {
-  opacity: 0.55;
-}
-
-.project-info {
-  display: flex;
-  align-items: baseline;
-  gap: var(--sp-2);
-  min-width: 0;
-}
-
-.project-name {
+.wt-choice-name {
+  flex: 0 0 auto;
   font-size: var(--fs-13);
   font-weight: 600;
   white-space: nowrap;
 }
 
-.recent-dir {
+.wt-choice-new .wt-choice-name {
   font-family: var(--font-mono);
-  font-size: var(--fs-12);
-  color: var(--muted);
-  overflow: hidden;
-  text-overflow: ellipsis;
-  white-space: nowrap;
+  color: var(--accent);
 }
 
-.recent-cmd {
-  flex: 0 0 auto;
+.wt-choice-sub {
+  min-width: 0;
   font-family: var(--font-mono);
   font-size: var(--fs-12);
+  line-height: 1.35;
   color: var(--muted);
-}
-
-.project-other .recent-dir {
-  font-family: inherit;
-  font-style: italic;
+  text-align: right;
+  overflow-wrap: anywhere;
 }
 
 .picker-empty {
@@ -2225,3 +2331,148 @@ textarea {
     background: oklch(0 0 0 / 0.5);
   }
 }
+
+/* ---------- retained worktrees (#84) ---------- */
+
+.worktrees {
+  padding: var(--sp-4);
+  max-width: 960px;
+  margin: 0 auto;
+}
+
+.wt-head {
+  margin-bottom: var(--sp-4);
+}
+
+.wt-title {
+  font-family: var(--font-mono);
+  font-size: var(--fs-15);
+  font-weight: 600;
+  color: var(--ink);
+  margin: 0 0 var(--sp-1);
+}
+
+.wt-sub {
+  color: var(--muted);
+  font-size: var(--fs-13);
+  margin: 0;
+}
+
+.wt-row {
+  display: flex;
+  align-items: baseline;
+  gap: var(--sp-3);
+  padding: var(--sp-2) var(--sp-2);
+  border-bottom: 1px solid var(--surface-2);
+  font-family: var(--font-mono);
+  font-size: var(--fs-13);
+  flex-wrap: wrap;
+}
+
+.wt-branch {
+  color: var(--ink);
+  font-weight: 600;
+}
+
+.wt-path {
+  color: var(--muted);
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.wt-reason {
+  color: var(--faint);
+}
+
+/* Status never rides on color alone: the label itself says what blocks. */
+.wt-way[data-clear] {
+  color: var(--faint);
+}
+
+.wt-way:not([data-clear]) {
+  color: var(--warn);
+}
+
+.wt-row .wt-reclaim-btn {
+  margin-left: auto;
+}
+
+.wt-row .wt-reclaim-btn::before {
+  content: "[";
+  color: var(--danger);
+}
+
+.wt-row .wt-reclaim-btn::after {
+  content: "]";
+  color: var(--danger);
+}
+
+.wt-row .wt-reclaim-btn:hover {
+  color: var(--danger);
+  background: var(--danger-tint);
+}
+
+.btn-danger {
+  color: var(--danger);
+  font-weight: 600;
+}
+
+.btn-danger:hover {
+  background: var(--danger-tint);
+}
+
+/* The destructive confirmation, centered over the section. */
+.wt-confirm {
+  position: fixed;
+  inset: 0;
+  z-index: var(--z-backdrop);
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  background: oklch(0 0 0 / 0.5);
+  padding: var(--sp-4);
+}
+
+.wt-confirm[hidden] {
+  display: none;
+}
+
+.wt-confirm-panel {
+  pointer-events: auto;
+  background: var(--bg);
+  border: 1px solid var(--surface-2);
+  padding: var(--sp-4);
+  max-width: 480px;
+  font-family: var(--font-sans);
+  display: flex;
+  flex-direction: column;
+  gap: var(--sp-2);
+}
+
+.wt-confirm-q {
+  margin: 0;
+  font-family: var(--font-mono);
+  font-weight: 600;
+  color: var(--ink);
+}
+
+.wt-confirm-way {
+  margin: 0;
+  font-family: var(--font-mono);
+  font-size: var(--fs-13);
+  color: var(--warn);
+}
+
+.wt-confirm-note {
+  margin: 0;
+  font-size: var(--fs-13);
+  color: var(--muted);
+}
+
+.wt-confirm-actions {
+  display: flex;
+  gap: var(--sp-2);
+  justify-content: flex-end;
+  margin-top: var(--sp-2);
+}

web/src/types.ts

@@ -31,6 +31,11 @@ export interface Session {
    * observed it (`#{pane_current_path}`) — distinct from `cwd` (the spawn dir).
    * Drives the directory-based session tree. Absent until first observed. */
   current_cwd?: string | null;
+  /** What currently blocks an unforced kill of this session (#83), as the
+   * daemon's watcher last probed it. Absent until probed and for sessions
+   * without a worktree; all counts default to 0 on the wire for older
+   * daemons. */
+  blocked_work?: InTheWay | null;
 }
 
 /** One directory's immediate subdirectories (NAP-329). */
@@ -113,7 +118,6 @@ export type Projects = Project[];
 export interface WorktreeSpec {
   base_repo: string;
   branch: string;
-  cleanup_on_kill?: boolean;
   /** When false, `branch` already exists and is checked out as-is (#61).
    * Defaults to true (create a new branch) on older daemons. */
   create_branch?: boolean;
@@ -133,6 +137,67 @@ export interface BranchInfo {
 /** `GET /api/branches?path=` — the local branches of one repository (#55). */
 export type Branches = BranchInfo[];
 
+/** Why a retained worktree outlived its session (#80). New values are
+ * additive; unknown reasons render generically. */
+export type RetainedReason = "force-killed" | "exited-with-unsaved-work";
+
+/** What currently blocks an unforced kill of a worktree's session (#80),
+ * recomputed by the daemon on every read. All counts default to 0 on the
+ * wire for older daemons. */
+export interface InTheWay {
+  uncommitted_files?: number;
+  untracked_files?: number;
+  unpushed_commits?: number;
+}
+
+/** One entry of `GET /api/worktrees` (#80): a retained worktree with its
+ * in-the-way state as of this read. Reclaiming it removes the directory but
+ * never the branch. Mirrors `maestro_protocol::RetainedWorktree`. */
+export interface RetainedWorktree {
+  id: Uuid;
+  path: string;
+  base_repo: string;
+  branch: string;
+  reason: RetainedReason;
+  retained_at: IsoTimestamp;
+  in_the_way?: InTheWay;
+}
+
+/** The phrasing `maestro_protocol::InTheWay`'s Display impl uses — shared by
+ * the kill refusal, the TUI and this client, so no two clients can describe
+ * the same tree differently. Zero parts are omitted; all-zero renders
+ * "no unsaved work". */
+export function formatInTheWay(w: InTheWay): string {
+  const parts: string[] = [];
+  const push = (n: number | undefined, unit: string): void => {
+    if (!n || n <= 0) return;
+    parts.push(n === 1 ? `1 ${unit}` : `${n} ${unit}s`);
+  };
+  push(w.uncommitted_files, "uncommitted file");
+  push(w.untracked_files, "untracked file");
+  push(w.unpushed_commits, "unpushed commit");
+  return parts.length > 0 ? parts.join(", ") : "no unsaved work";
+}
+
+/** Same reason labels the CLI table and the TUI overlay use; unknown future
+ * reasons render their raw wire value. */
+export function reasonLabel(reason: RetainedReason): string {
+  return reason;
+}
+
+/** #83: this session's blocked-work breakdown when something actually blocks
+ * an unforced kill; `null` while clear or not yet probed. Render it with
+ * {@link formatInTheWay} so every client phrases it identically. */
+export function sessionBlockers(s: Session): InTheWay | null {
+  const w = s.blocked_work;
+  if (!w) return null;
+  const blocked =
+    (w.uncommitted_files ?? 0) > 0 ||
+    (w.untracked_files ?? 0) > 0 ||
+    (w.unpushed_commits ?? 0) > 0;
+  return blocked ? w : null;
+}
+
 export interface CreateSessionRequest {
   cwd: string;
   command: string;

web/src/worktreeStep.test.ts

@@ -0,0 +1,233 @@
+// @vitest-environment happy-dom
+// Second step of the working-directory picker (#95). See the interaction rules
+// block in spawnForm.ts for what each choice means.
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+
+import { createSpawnForm, type SpawnFormHandle, type SpawnFormValues } from "./spawnForm.js";
+import type { Project } from "./types.js";
+
+const MAESTRO: Project = {
+  path: "/home/user/tea/maestro",
+  name: "maestro",
+  is_worktree: false,
+  last_activity: "2026-08-20T10:00:00Z",
+  last_command: "claude",
+};
+
+const WT_A: Project = {
+  path: "/home/user/tea/maestro/worktrees/bulgarians",
+  name: "bulgarians",
+  is_worktree: true,
+  base_repo: MAESTRO.path,
+  last_activity: "2026-08-22T10:00:00Z",
+};
+
+const WT_B: Project = {
+  path: "/home/user/tea/maestro/worktrees/spawn-v2",
+  name: "spawn-v2",
+  is_worktree: true,
+  base_repo: MAESTRO.path,
+  last_activity: "2026-08-21T10:00:00Z",
+};
+
+const OTHER: Project = {
+  path: "/home/user/tea/rev",
+  name: "rev",
+  is_worktree: false,
+  last_activity: "2026-08-19T10:00:00Z",
+};
+
+function stubFetch(projects: Project[]): string[] {
+  const urls: string[] = [];
+  vi.stubGlobal(
+    "fetch",
+    vi.fn(async (input: RequestInfo | URL) => {
+      const url = String(input);
+      urls.push(url);
+      const body = url.includes("/api/projects")
+        ? projects
+        : url.includes("/api/names")
+          ? { names: ["amber-fox"] }
+          : url.includes("/api/branches")
+            ? []
+            : { hostname: "h", version: "0", home_dir: "/home/user", presets: [] };
+      return new Response(JSON.stringify(body), { status: 200 });
+    }),
+  );
+  return urls;
+}
+
+describe("spawnForm worktree step (#95)", () => {
+  let handle: SpawnFormHandle | null = null;
+  let urls: string[] = [];
+  let changes: SpawnFormValues[] = [];
+
+  beforeEach(() => {
+    vi.useFakeTimers({ now: Date.parse("2026-08-23T12:00:00Z") });
+    changes = [];
+  });
+
+  afterEach(() => {
+    handle?.destroy();
+    handle = null;
+    vi.unstubAllGlobals();
+    vi.useRealTimers();
+  });
+
+  const drain = async () => {
+    for (let i = 0; i < 40; i++) await Promise.resolve();
+  };
+
+  async function mount(projects: Project[]): Promise<HTMLFormElement> {
+    urls = stubFetch(projects);
+    handle = createSpawnForm({ onSuccess() {}, onChange: (v) => changes.push(v) });
+    document.body.appendChild(handle.el);
+    await drain();
+    return handle.el;
+  }
+
+  const step = (form: HTMLFormElement) => form.querySelector<HTMLElement>(".wt-step")!;
+  const choices = (form: HTMLFormElement) => [
+    ...form.querySelectorAll<HTMLButtonElement>(".wt-choice"),
+  ];
+  const activeChoice = (form: HTMLFormElement) =>
+    form.querySelector<HTMLButtonElement>(".wt-choice.is-active");
+  const box = (form: HTMLFormElement, path: string) =>
+    form.querySelector<HTMLButtonElement>(`.project-box[data-cwd="${path}"]`)!;
+  const toggle = (form: HTMLFormElement) =>
+    form.querySelector<HTMLInputElement>("input[name=worktree_enabled]")!;
+
+  it("hides the worktree step until a project is picked", async () => {
+    const form = await mount([MAESTRO, WT_A]);
+    expect(step(form).hidden).toBe(true);
+    expect(choices(form)).toEqual([]);
+
+    box(form, MAESTRO.path).click();
+    await drain();
+
+    expect(step(form).hidden).toBe(false);
+  });
+
+  it("lists '+ new' first and selected by default, then the project's worktrees", async () => {
+    const form = await mount([MAESTRO, WT_A, WT_B]);
+    box(form, MAESTRO.path).click();
+    await drain();
+
+    const labels = choices(form).map((c) => c.querySelector(".wt-choice-name")!.textContent);
+    expect(labels).toEqual(["+ new", "bulgarians", "spawn-v2"]);
+    expect(activeChoice(form)!.dataset.kind).toBe("new");
+  });
+
+  it("taking the '+ new' default runs in the repo with the create toggle on", async () => {
+    const form = await mount([MAESTRO, WT_A]);
+    box(form, MAESTRO.path).click();
+    await drain();
+
+    expect(changes.at(-1)!.cwd).toBe(MAESTRO.path);
+    expect(changes.at(-1)!.worktreeEnabled).toBe(true);
+    expect(toggle(form).checked).toBe(true);
+    expect(form.querySelector<HTMLElement>(".wt-repo")!.textContent).toContain(MAESTRO.path);
+    // The scan already knows the repo — no probe.
+    expect(urls.some((u) => u.includes("/api/gitroot"))).toBe(false);
+  });
+
+  it("picking an existing worktree runs in it with the create toggle off (#91)", async () => {
+    const form = await mount([MAESTRO, WT_A, WT_B]);
+    box(form, MAESTRO.path).click();
+    await drain();
+
+    const existing = choices(form).find((c) => c.dataset.cwd === WT_A.path)!;
+    existing.click();
+    await drain();
+
+    expect(changes.at(-1)!.cwd).toBe(WT_A.path);
+    expect(changes.at(-1)!.worktreeEnabled).toBe(false);
+    expect(toggle(form).checked).toBe(false);
+    expect(form.querySelector<HTMLElement>(".wt-body")!.hidden).toBe(true);
+    expect(existing.classList.contains("is-active")).toBe(true);
+    // Still no probe: the scan reported this worktree's repo membership.
+    expect(urls.some((u) => u.includes("/api/gitroot"))).toBe(false);
+    // The project box stays marked — it is what the worktree list belongs to.
+    expect(box(form, MAESTRO.path).classList.contains("is-active")).toBe(true);
+  });
+
+  it("switching back to '+ new' re-enables the create toggle", async () => {
+    const form = await mount([MAESTRO, WT_A]);
+    box(form, MAESTRO.path).click();
+    await drain();
+    choices(form)
+      .find((c) => c.dataset.cwd === WT_A.path)!
+      .click();
+    await drain();
+
+    choices(form)
+      .find((c) => c.dataset.kind === "new")!
+      .click();
+    await drain();
+
+    expect(changes.at(-1)!.cwd).toBe(MAESTRO.path);
+    expect(changes.at(-1)!.worktreeEnabled).toBe(true);
+    expect(toggle(form).checked).toBe(true);
+  });
+
+  it("repopulates and resets to '+ new' when another project is picked", async () => {
+    const form = await mount([MAESTRO, WT_A, OTHER]);
+    box(form, MAESTRO.path).click();
+    await drain();
+    choices(form)
+      .find((c) => c.dataset.cwd === WT_A.path)!
+      .click();
+    await drain();
+
+    box(form, OTHER.path).click();
+    await drain();
+
+    expect(choices(form).map((c) => c.dataset.kind)).toEqual(["new"]);
+    expect(activeChoice(form)!.dataset.kind).toBe("new");
+    expect(changes.at(-1)!.cwd).toBe(OTHER.path);
+    expect(changes.at(-1)!.worktreeEnabled).toBe(true);
+  });
+
+  it("defaults to the worktree itself when the box is a linked worktree (#91)", async () => {
+    // No main checkout in the scan, so the orphan worktree is its own box.
+    const form = await mount([WT_A]);
+    box(form, WT_A.path).click();
+    await drain();
+
+    expect(activeChoice(form)!.dataset.cwd).toBe(WT_A.path);
+    expect(changes.at(-1)!.cwd).toBe(WT_A.path);
+    expect(changes.at(-1)!.worktreeEnabled).toBe(false);
+    expect(toggle(form).checked).toBe(false);
+    expect(form.querySelector<HTMLElement>(".wt-body")!.hidden).toBe(true);
+  });
+
+  it("hides the worktree step again when the operator takes the raw-input hatch", async () => {
+    const form = await mount([MAESTRO, WT_A]);
+    box(form, MAESTRO.path).click();
+    await drain();
+    expect(step(form).hidden).toBe(false);
+
+    form.querySelector<HTMLButtonElement>(".project-other")!.click();
+    await drain();
+
+    expect(step(form).hidden).toBe(true);
+    expect(choices(form)).toEqual([]);
+    expect(form.querySelector(".project-box.is-active")).toBeNull();
+  });
+
+  it("restores the picked worktree from a draft seed", async () => {
+    urls = stubFetch([MAESTRO, WT_A, WT_B]);
+    handle = createSpawnForm({
+      onSuccess() {},
+      seed: { cwd: WT_A.path, cwdRawVisible: false, worktreeEnabled: false },
+    });
+    document.body.appendChild(handle.el);
+    await drain();
+    const form = handle.el;
+
+    expect(step(form).hidden).toBe(false);
+    expect(activeChoice(form)!.dataset.cwd).toBe(WT_A.path);
+    expect(box(form, MAESTRO.path).classList.contains("is-active")).toBe(true);
+    expect(toggle(form).checked).toBe(false);
+  });
+});

web/src/worktrees.test.ts

@@ -0,0 +1,114 @@
+// @vitest-environment happy-dom
+import { describe, expect, it } from "vitest";
+
+import { createWorktreesView } from "./worktreesView.js";
+import type { RetainedWorktree } from "./types.js";
+
+function worktree(overrides: Partial<RetainedWorktree>): RetainedWorktree {
+  return {
+    id: "11111111-2222-3333-4444-555555555555",
+    path: "/home/naps/tea/maestro/worktrees/feat/login",
+    base_repo: "/home/naps/tea/maestro",
+    branch: "feat/login",
+    reason: "force-killed",
+    retained_at: "2026-08-24T10:00:00Z",
+    in_the_way: {
+      uncommitted_files: 2,
+      untracked_files: 1,
+      unpushed_commits: 3,
+    },
+    ...overrides,
+  };
+}
+
+/** Mount a view over a scripted store and return (el, reclaimed-ids). */
+function mount(items: RetainedWorktree[], homeDir = "/home/naps") {
+  const reclaimed: string[] = [];
+  const view = createWorktreesView({
+    load: async () => items,
+    reclaim: async (id) => {
+      reclaimed.push(id);
+      items.splice(
+        items.findIndex((w) => w.id === id),
+        1,
+      );
+    },
+    homeDir: () => homeDir,
+  });
+  document.body.appendChild(view.el);
+  return { view, reclaimed };
+}
+
+describe("retained-worktrees view (#84)", () => {
+  it("lists branch, abbreviated path, reason and what is in the way", async () => {
+    const { view } = mount([
+      worktree({
+        path: "/home/naps/tea/maestro/worktrees/feat/login",
+      }),
+    ]);
+    await view.refresh();
+    const text = view.el.textContent ?? "";
+    expect(text).toContain("feat/login");
+    // Sidebar-style abbreviation of the path against the daemon's home dir,
+    // full path kept in the tooltip.
+    expect(text).toContain("t/m/w/f/login");
+    const pathEl = view.el.querySelector<HTMLElement>(".wt-path")!;
+    expect(pathEl.title).toBe("/home/naps/tea/maestro/worktrees/feat/login");
+    // Same reason labels as `maestro worktrees list` and the TUI overlay.
+    expect(text).toContain("force-killed");
+    // Same phrasing as InTheWay's Display impl — shared with the kill refusal.
+    expect(text).toContain("2 uncommitted files, 1 untracked file, 3 unpushed commits");
+  });
+
+  it("says a tree whose work has since been pushed is clear", async () => {
+    const { view } = mount([worktree({ in_the_way: {} })]);
+    await view.refresh();
+    expect(view.el.textContent).toContain("no unsaved work");
+  });
+
+  it("renders an empty store as a normal state, not an error", async () => {
+    const { view } = mount([]);
+    await view.refresh();
+    const text = view.el.textContent ?? "";
+    expect(text).toContain("no retained worktrees");
+    expect(text.toLowerCase()).not.toContain("error");
+    expect(text.toLowerCase()).not.toContain("failed");
+  });
+
+  it("guards reclaim with a confirmation that names what is lost and that the branch survives", async () => {
+    const wt = worktree({ branch: "feat/login" });
+    const { view, reclaimed } = mount([wt]);
+    await view.refresh();
+
+    view.el.querySelector<HTMLButtonElement>(".wt-reclaim-btn")!.click();
+    const confirmText = view.el.querySelector<HTMLElement>(".wt-confirm")!.textContent ?? "";
+    expect(confirmText).toContain("Reclaim worktree feat/login?");
+    // Names what will be lost before it happens…
+    expect(confirmText).toContain(
+      "2 uncommitted files, 1 untracked file, 3 unpushed commits",
+    );
+    // …and says reclaim does not take the commits too.
+    expect(confirmText).toContain("never deleted");
+
+    view.el.querySelector<HTMLButtonElement>(".wt-confirm-cancel")!.click();
+    expect(reclaimed).toEqual([]);
+
+    view.el.querySelector<HTMLButtonElement>(".wt-reclaim-btn")!.click();
+    view.el.querySelector<HTMLButtonElement>(".wt-confirm-go")!.click();
+    await Promise.resolve();
+    await Promise.resolve();
+    expect(reclaimed).toEqual(["11111111-2222-3333-4444-555555555555"]);
+    // The row is gone once the refresh lands.
+    expect(view.el.textContent).toContain("no retained worktrees");
+  });
+
+  it("sorts oldest-retained first, like every other client", async () => {
+    const { view } = mount([
+      worktree({ branch: "newer", retained_at: "2026-08-24T12:00:00Z" }),
+      worktree({ branch: "older", retained_at: "2026-08-24T08:00:00Z" }),
+    ]);
+    await view.refresh();
+    const branches = [...view.el.querySelectorAll(".wt-branch")].map((n) => n.textContent);
+    expect(branches).toEqual(["older", "newer"]);
+  });
+});

web/src/worktreesView.ts

@@ -0,0 +1,166 @@
+// Retained-worktrees view (#84): every worktree the daemon is holding that no
+// session uses, listed from `GET /api/worktrees` with a reclaim action.
+//
+// Wording is shared with the CLI (`maestro worktrees list`) and the TUI
+// overlay: same reason labels, same in-the-way phrasing via
+// `formatInTheWay` (the mirror of `InTheWay`'s Display impl). Reclaim reads
+// as what it is — destructive — naming what will be lost before it happens
+// and saying out loud that the branch survives (docs/WORKTREES.md).
+
+import { escapeHtml } from "./html.js";
+import {
+  abbreviateCwd,
+  abbreviateFolderName,
+  formatInTheWay,
+  reasonLabel,
+  type RetainedWorktree,
+  type Uuid,
+} from "./types.js";
+
+export interface WorktreesDeps {
+  /** `GET /api/worktrees`. */
+  load(): Promise<RetainedWorktree[]>;
+  /** `DELETE /api/worktrees/:id`. */
+  reclaim(id: Uuid): Promise<void>;
+  /** The daemon's home dir, for `~` abbreviation of paths. */
+  homeDir(): string | undefined;
+}
+
+export interface WorktreesViewHandle {
+  el: HTMLElement;
+  /** Re-fetch the store and re-render. Safe to call repeatedly. */
+  refresh(): Promise<void>;
+  dispose(): void;
+}
+
+/** Oldest-retained first, matching `maestro worktrees list`'s ordering. */
+function sorted(items: RetainedWorktree[]): RetainedWorktree[] {
+  return [...items].sort(
+    (a, b) => Date.parse(a.retained_at) - Date.parse(b.retained_at),
+  );
+}
+
+export function createWorktreesView(deps: WorktreesDeps): WorktreesViewHandle {
+  const el = document.createElement("section");
+  el.className = "worktrees";
+  el.innerHTML = `
+    <header class="wt-head">
+      <h2 class="wt-title">retained worktrees</h2>
+      <p class="wt-sub">
+        Kept when a session ended with unsaved work. Reclaiming removes the
+        directory only; branches are never deleted.
+      </p>
+    </header>
+    <div class="wt-list"></div>
+    <div class="wt-confirm" role="alertdialog" aria-modal="true" hidden></div>
+  `;
+  const listHost = el.querySelector<HTMLElement>(".wt-list")!;
+  const confirmEl = el.querySelector<HTMLElement>(".wt-confirm")!;
+
+  let pendingId: string | null = null;
+
+  const render = (items: RetainedWorktree[]) => {
+    listHost.replaceChildren();
+    if (items.length === 0) {
+      // A drained store is the normal state — say so plainly, not like
+      // something went wrong.
+      const empty = document.createElement("div");
+      empty.className = "empty";
+      empty.innerHTML = `
+        <div class="empty-glyph" aria-hidden="true">⌂</div>
+        <div class="empty-title">no retained worktrees</div>
+        <p class="empty-hint">Nothing is being held. Worktrees kept after a force-kill or an unsaved exit show up here.</p>`;
+      listHost.appendChild(empty);
+      return;
+    }
+    const home = deps.homeDir();
+    for (const w of sorted(items)) {
+      listHost.appendChild(renderRow(w, home));
+    }
+  };
+
+  const renderRow = (w: RetainedWorktree, home: string | undefined): HTMLElement => {
+    const row = document.createElement("div");
+    row.className = "wt-row";
+    const clear = formatInTheWay(w.in_the_way ?? {}) === "no unsaved work";
+    row.innerHTML = `
+      <span class="wt-branch">${escapeHtml(w.branch)}</span>
+      <span class="wt-path" title="${escapeHtml(w.path)}">${abbreviateFolderName(abbreviateCwd(w.path, home))}</span>
+      <span class="wt-reason">${escapeHtml(reasonLabel(w.reason))}</span>
+      <span class="wt-way"${clear ? ' data-clear="true"' : ""}>${escapeHtml(formatInTheWay(w.in_the_way ?? {}))}</span>
+      <button class="btn wt-reclaim-btn" type="button">Reclaim</button>
+    `;
+    row.querySelector(".wt-reclaim-btn")!.addEventListener("click", () => {
+      showConfirm(w);
+    });
+    return row;
+  };
+
+  const showConfirm = (w: RetainedWorktree) => {
+    pendingId = w.id;
+    // Mirrors the TUI's ReclaimConfirm line for line: what goes away, what is
+    // in the way right now, and that the branch survives reclaim.
+    confirmEl.innerHTML = `
+      <div class="wt-confirm-panel">
+        <p class="wt-confirm-q">Reclaim worktree ${escapeHtml(w.branch)}?</p>
+        <p class="wt-confirm-way">Currently in the way: ${escapeHtml(formatInTheWay(w.in_the_way ?? {}))}</p>
+        <p class="wt-confirm-note">The directory is removed; the branch is never deleted.</p>
+        <div class="wt-confirm-actions">
+          <button class="btn btn-danger wt-confirm-go" type="button">Reclaim</button>
+          <button class="btn btn-ghost wt-confirm-cancel" type="button">Cancel</button>
+        </div>
+      </div>`;
+    confirmEl.hidden = false;
+    confirmEl.querySelector<HTMLButtonElement>(".wt-confirm-go")!.focus();
+  };
+
+  const hideConfirm = () => {
+    pendingId = null;
+    confirmEl.hidden = true;
+    confirmEl.replaceChildren();
+  };
+
+  confirmEl.addEventListener("click", async (e) => {
+    const target = e.target as HTMLElement;
+    if (target.closest(".wt-confirm-cancel")) {
+      hideConfirm();
+      return;
+    }
+    if (!target.closest(".wt-confirm-go") || !pendingId) return;
+    const id = pendingId;
+    hideConfirm();
+    try {
+      await deps.reclaim(id);
+    } catch (err) {
+      alert(`Failed to reclaim: ${(err as Error).message}`);
+    }
+    await refresh();
+  });
+
+  const onKey = (e: KeyboardEvent) => {
+    if (e.key === "Escape" && !confirmEl.hidden) hideConfirm();
+  };
+  document.addEventListener("keydown", onKey);
+
+  const refresh = async () => {
+    try {
+      render(await deps.load());
+    } catch (err) {
+      listHost.replaceChildren();
+      const fail = document.createElement("div");
+      fail.className = "empty";
+      fail.innerHTML = `<div class="empty-title">Couldn't load retained worktrees</div><p class="empty-hint"></p>`;
+      fail.querySelector(".empty-hint")!.textContent = (err as Error).message;
+      listHost.appendChild(fail);
+    }
+  };
+
+  return {
+    el,
+    refresh,
+    dispose() {
+      document.removeEventListener("keydown", onKey);
+      el.remove();
+    },
+  };
+}