Merge remote-tracking branch 'origin/main' into themes

Solarized (dark/light), Catppuccin Mocha, GitHub (dark/light),
Tokyo Night, Gruvbox, Nord, Dracula. Colours auto-tuned from the
canonical seeds to clear the palette contrast floors; tests now
assert every RGB preset, not just dark/light.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

.gitea/workflows/ci.yml

@@ -97,3 +97,34 @@ 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
+
+      # The runner container is root with no `nixbld` group, but the installer
+      # writes `build-users-group = nixbld` anyway and then fails on it, so the
+      # config goes in first. Flakes are off by default and `nix build .#…`
+      # needs them. Written again afterwards in case the installer replaced it.
+      - name: Install nix
+        run: |
+          mkdir -p /etc/nix
+          printf 'build-users-group =\nexperimental-features = nix-command flakes\n' > /etc/nix/nix.conf
+          curl -fsSL https://nixos.org/nix/install | sh -s -- --no-daemon --yes
+          printf 'build-users-group =\nexperimental-features = nix-command flakes\n' > /etc/nix/nix.conf
+          echo "$HOME/.nix-profile/bin" >> "$GITHUB_PATH"
+
+      # The installer does not enable flakes, so `nix build .#…` needs the
+      # features passed explicitly — a local machine that has them in
+      # nix.conf will build fine while CI fails without this.
+      - name: build flake packages
+        run: |
+          nix --extra-experimental-features "nix-command flakes" build \
+            .#webFrontend \
+            .#maestro \
+            .#maestro-web \
+            --no-link

CLAUDE.md

@@ -66,6 +66,10 @@ See `docs/INSTALL.md` for end-user install instructions.
 collisions, what blocks a kill, what `--force` retains, and what reclaim
 touches. Read it before changing anything that creates or removes one.
 
+`docs/SIDEBAR.md` is the contract for session cards in the web and TUI
+sidebars — line layout, activity colours, duration format, state precedence.
+Read it before changing sidebar rendering.
+
 `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

Cargo.lock

@@ -1065,6 +1065,7 @@ dependencies = [
  "futures-util",
  "libc",
  "maestro-config",
+ "maestro-hooks",
  "maestro-protocol",
  "maestro-testing",
  "nix",
@@ -1102,6 +1103,7 @@ dependencies = [
  "futures-util",
  "libc",
  "maestro-config",
+ "maestro-hooks",
  "maestro-names",
  "maestro-protocol",
  "reqwest",
@@ -1137,6 +1139,15 @@ dependencies = [
  "uuid",
 ]
 
+[[package]]
+name = "maestro-hooks"
+version = "0.1.0"
+dependencies = [
+ "serde_json",
+ "tempfile",
+ "thiserror 1.0.69",
+]
+
 [[package]]
 name = "maestro-installer"
 version = "0.1.0"

Cargo.toml

@@ -18,6 +18,7 @@ dirs = "5"
 futures-util = { version = "0.3", default-features = false, features = ["sink", "std"] }
 libc = "0.2"
 maestro-config = { path = "crates/maestro-config" }
+maestro-hooks = { path = "crates/maestro-hooks" }
 maestro-names = { path = "crates/maestro-names" }
 maestro-protocol = { path = "crates/maestro-protocol" }
 maestro-testing = { path = "crates/maestro-testing" }

crates/maestro-cli/Cargo.toml

@@ -17,6 +17,7 @@ dirs.workspace = true
 futures-util.workspace = true
 libc.workspace = true
 maestro-config.workspace = true
+maestro-hooks.workspace = true
 maestro-protocol = { workspace = true, features = ["client"] }
 nix.workspace = true
 serde_json.workspace = true

crates/maestro-cli/src/cli.rs

@@ -43,6 +43,23 @@ pub enum Command {
     Kill(KillArgs),
     /// List retained worktrees, or reclaim one by ID (#86).
     Worktrees(WorktreesArgs),
+    /// Install or update the agent activity hook (#106).
+    Hooks(HooksArgs),
+}
+
+/// `maestro hooks <install>`
+#[derive(Debug, clap::Args)]
+pub struct HooksArgs {
+    #[command(subcommand)]
+    pub command: HooksCommand,
+}
+
+#[derive(Debug, Subcommand)]
+pub enum HooksCommand {
+    /// Write the Claude Code activity hook into ~/.claude/settings.json.
+    /// Idempotent: an older maestro hook is updated in place, every other
+    /// hook is left untouched.
+    Install,
 }
 
 /// `maestro worktrees <list|reclaim>`
@@ -275,6 +292,23 @@ mod tests {
         assert!(err.to_string().contains("KEY=VALUE"));
     }
 
+    #[test]
+    fn parses_hooks_install() {
+        let cli = Cli::try_parse_from(["maestro", "hooks", "install"]).unwrap();
+        match cli.command {
+            Command::Hooks(h) => {
+                assert!(matches!(h.command, HooksCommand::Install));
+            }
+            _ => panic!("wrong subcommand"),
+        }
+        // No subcommand → help, like `worktrees`.
+        let err = Cli::try_parse_from(["maestro", "hooks"]).unwrap_err();
+        assert!(matches!(
+            err.kind(),
+            clap::error::ErrorKind::DisplayHelpOnMissingArgumentOrSubcommand
+        ));
+    }
+
     #[test]
     fn parses_worktrees_list() {
         let cli = Cli::try_parse_from(["maestro", "worktrees", "list", "--json"]).unwrap();

crates/maestro-cli/src/dispatch.rs

@@ -24,6 +24,10 @@ pub enum CliError {
     #[error("{0}")]
     Attach(#[from] crate::attach::AttachError),
     #[error("{0}")]
+    Hooks(#[from] maestro_hooks::HooksError),
+    #[error("could not determine the home directory ($HOME unset?)")]
+    NoHome,
+    #[error("{0}")]
     Io(#[from] std::io::Error),
 }
 
@@ -40,6 +44,15 @@ pub async fn dispatch(
         None => default_config_path()?,
     };
 
+    // `hooks install` is purely local: it must work with the daemon down, so
+    // it never touches the client.
+    if let Command::Hooks(args) = &command {
+        match args.command {
+            crate::cli::HooksCommand::Install => run_hooks_install()?,
+        }
+        return Ok(());
+    }
+
     let daemon = client(&config_path, daemon_url_override)?;
 
     match command {
@@ -77,6 +90,7 @@ pub async fn dispatch(
                 );
             }
         }
+        Command::Hooks(_) => unreachable!("hooks handled before the daemon client exists"),
         Command::Worktrees(args) => match args.command {
             WorktreesCommand::List(list_args) => {
                 let mut stdout = std::io::stdout().lock();
@@ -101,6 +115,25 @@ pub async fn dispatch(
     Ok(())
 }
 
+/// `maestro hooks install` (#106): write the shipped hook script under the
+/// user's data dir and register it in their Claude Code settings. Idempotent
+/// and foreign-hook-preserving — the guarantees live in [`maestro_hooks`].
+#[allow(clippy::result_large_err)]
+fn run_hooks_install() -> Result<(), CliError> {
+    let home = dirs::home_dir().ok_or(CliError::NoHome)?;
+    let changed = maestro_hooks::install_for_home(&home)?;
+    if changed {
+        println!(
+            "installed claude-code activity hook: {} → {}",
+            maestro_hooks::script_path(&home).display(),
+            maestro_hooks::settings_path(&home).display()
+        );
+    } else {
+        println!("claude-code activity hook already up to date");
+    }
+    Ok(())
+}
+
 /// Default detach byte, matching `maestro attach --detach-key`'s `^q`.
 const CTRL_Q: u8 = 0x11;
 

crates/maestro-cli/src/sessions.rs

@@ -3,6 +3,7 @@
 use std::collections::HashMap;
 use std::io::Write;
 
+use maestro_protocol::display::abbreviate_dir;
 use maestro_protocol::{
     ActivityState, ClientError, CreateSessionRequest, DaemonClient, DaemonInfo, Session,
     SessionStatus, WorktreeSpec,
@@ -108,6 +109,7 @@ fn print_session_table(out: &mut impl Write, sessions: &[Session], info: &Daemon
             ActivityState::Active => "active",
             ActivityState::Idle => "idle",
             ActivityState::AwaitingInput => "awaiting",
+            ActivityState::Error => "error",
         };
         // Show the live foreground command alongside the spawn command when
         // the daemon has observed one that differs (NAP-340).
@@ -137,21 +139,6 @@ pub(crate) fn blocked_label(s: &Session) -> 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.
-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 {
-            return "~".into();
-        }
-        if let Some(rest) = p.strip_prefix(&format!("{home}/")) {
-            return format!("~/{rest}");
-        }
-    }
-    p.into_owned()
-}
-
 #[cfg(test)]
 mod tests {
     use std::collections::HashMap;
@@ -175,7 +162,9 @@ mod tests {
             created_at: Utc.with_ymd_and_hms(2026, 5, 25, 12, 0, 0).unwrap(),
             foreground: None,
             activity: Default::default(),
+            activity_detail: None,
             last_activity_at: chrono::Utc::now(),
+            activity_since: chrono::Utc::now(),
             current_cwd: None,
             blocked_work: None,
         }

crates/maestro-cli/src/worktrees.rs

@@ -6,10 +6,10 @@
 
 use std::io::Write;
 
+use maestro_protocol::display::abbreviate_dir;
 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(

crates/maestro-config/src/lib.rs

@@ -22,7 +22,8 @@ use std::collections::BTreeMap;
 use std::net::SocketAddr;
 use std::path::{Path, PathBuf};
 
-use serde::Deserialize;
+use serde::de::Error as _;
+use serde::{Deserialize, Deserializer};
 
 /// Directory name under `$XDG_CONFIG_HOME` (default `~/.config`).
 pub const DIR_NAME: &str = "maestro";
@@ -64,6 +65,24 @@ pub struct MaestroConfigFile {
     pub tui: TuiSection,
     #[serde(default)]
     pub spawn: SpawnSection,
+    #[serde(default)]
+    pub hooks: HooksSection,
+}
+
+/// `[hooks]` — agent-hook installation settings (#106).
+#[derive(Debug, Clone, Default, PartialEq, Eq, Deserialize)]
+pub struct HooksSection {
+    /// Whether the daemon installs the Claude Code activity hook into
+    /// `~/.claude/settings.json` on first start when no maestro hook is
+    /// there yet. Default `true`; set `auto_install = false` to opt out.
+    #[serde(default)]
+    pub auto_install: Option<bool>,
+}
+
+impl HooksSection {
+    pub fn auto_install(&self) -> bool {
+        self.auto_install.unwrap_or(true)
+    }
 }
 
 #[derive(Debug, Clone, Default, PartialEq, Eq, Deserialize)]
@@ -128,11 +147,14 @@ pub struct WebSection {
 
 /// `[tui]` — `maestro tui` settings (NAP-275 epic, phase 2 NAP-277).
 ///
-/// Leader key, chord timeout, and per-mode keymap overrides. The TUI ships
+/// Theme, leader key, chord timeout, and per-mode keymap overrides. The TUI
-/// with a default keymap; entries in `keymap_normal` / `keymap_insert` are
+/// ships with a default keymap; entries in `keymap_normal` / `keymap_insert`
-/// applied **over** the defaults, so a partial override is enough.
+/// are applied **over** the defaults, so a partial override is enough.
 #[derive(Debug, Clone, Default, PartialEq, Eq, Deserialize)]
 pub struct TuiSection {
+    /// Named palette preset. Defaults to the dark preset.
+    #[serde(default, deserialize_with = "deserialize_theme")]
+    pub theme: Option<TuiTheme>,
     /// Canonical key form, e.g. `"ctrl-a"`. Default `ctrl-a`.
     #[serde(default)]
     pub leader: Option<String>,
@@ -149,6 +171,75 @@ pub struct TuiSection {
     pub keymap_insert: BTreeMap<String, String>,
 }
 
+/// Palette presets supported by the TUI's `[tui].theme` setting.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum TuiTheme {
+    /// The terminal-native dark palette and the default.
+    Dark,
+    /// A high-contrast light palette.
+    Light,
+    /// Named ANSI colours, allowing the terminal to provide the colour set.
+    Ansi,
+    /// Solarized Dark.
+    SolarizedDark,
+    /// Solarized Light.
+    SolarizedLight,
+    /// Catppuccin Mocha.
+    Catppuccin,
+    /// GitHub Dark.
+    GithubDark,
+    /// GitHub Light.
+    GithubLight,
+    /// Tokyo Night.
+    TokyoNight,
+    /// Gruvbox Dark.
+    Gruvbox,
+    /// Nord.
+    Nord,
+    /// Dracula.
+    Dracula,
+}
+
+/// Every `[tui].theme` name and its variant, in documentation order.
+pub const TUI_THEMES: &[(&str, TuiTheme)] = &[
+    ("dark", TuiTheme::Dark),
+    ("light", TuiTheme::Light),
+    ("ansi", TuiTheme::Ansi),
+    ("solarized-dark", TuiTheme::SolarizedDark),
+    ("solarized-light", TuiTheme::SolarizedLight),
+    ("catppuccin", TuiTheme::Catppuccin),
+    ("github-dark", TuiTheme::GithubDark),
+    ("github-light", TuiTheme::GithubLight),
+    ("tokyo-night", TuiTheme::TokyoNight),
+    ("gruvbox", TuiTheme::Gruvbox),
+    ("nord", TuiTheme::Nord),
+    ("dracula", TuiTheme::Dracula),
+];
+
+fn deserialize_theme<'de, D>(deserializer: D) -> Result<Option<TuiTheme>, D::Error>
+where
+    D: Deserializer<'de>,
+{
+    let raw = Option::<String>::deserialize(deserializer)?;
+    raw.map(|name| {
+        TUI_THEMES
+            .iter()
+            .find(|(n, _)| *n == name)
+            .map(|(_, theme)| *theme)
+            .ok_or_else(|| {
+                let known = TUI_THEMES
+                    .iter()
+                    .map(|(n, _)| format!("{n:?}"))
+                    .collect::<Vec<_>>()
+                    .join(", ");
+                D::Error::custom(format!(
+                    "invalid [tui].theme {name:?}; expected one of {known}"
+                ))
+            })
+    })
+    .transpose()
+}
+
 /// `[spawn]` — command presets for the spawn form (#22, part of #21).
 ///
 /// Defined in shared config so every binary sees the same list: the web reads
@@ -375,6 +466,26 @@ mod tests {
         assert_eq!(cfg, MaestroConfigFile::default());
     }
 
+    #[test]
+    fn hooks_auto_install_defaults_true_and_is_opt_out() {
+        // Absent file / absent [hooks] ⇒ auto_install on.
+        assert!(HooksSection::default().auto_install());
+        let dir = tempfile::tempdir().unwrap();
+        let path = dir.path().join("config.toml");
+        std::fs::write(&path, "").unwrap();
+        assert!(MaestroConfigFile::load(&path).unwrap().hooks.auto_install());
+
+        std::fs::write(
+            &path,
+            r#"
+[hooks]
+auto_install = false
+"#,
+        )
+        .unwrap();
+        assert!(!MaestroConfigFile::load(&path).unwrap().hooks.auto_install());
+    }
+
     #[test]
     fn spawn_presets_default_to_builtins_plus_custom() {
         // Absent [spawn].presets → built-ins, with the implicit custom tile last.
@@ -558,6 +669,29 @@ bind_addr = "127.0.0.1:9090"
         );
     }
 
+    #[test]
+    fn tui_theme_parses_named_presets_and_defaults_when_absent() {
+        assert_eq!(TuiSection::default().theme, None);
+        for (name, theme) in TUI_THEMES {
+            let cfg = file_with(&format!("[tui]\ntheme = \"{name}\"\n"));
+            assert_eq!(cfg.tui.theme, Some(*theme));
+        }
+    }
+
+    #[test]
+    fn tui_theme_rejects_unknown_names_with_the_field_name() {
+        let err = toml::from_str::<MaestroConfigFile>("[tui]\ntheme = \"glorb\"\n").unwrap_err();
+        let message = err.to_string();
+        assert!(
+            message.contains("[tui].theme"),
+            "diagnostic should name the field: {message}"
+        );
+        assert!(
+            message.contains("glorb"),
+            "diagnostic should name the invalid value: {message}"
+        );
+    }
+
     fn file_with(body: &str) -> MaestroConfigFile {
         toml::from_str(body).expect("parse")
     }

crates/maestro-daemon/Cargo.toml

@@ -18,6 +18,7 @@ dirs.workspace = true
 futures-util.workspace = true
 libc.workspace = true
 maestro-config.workspace = true
+maestro-hooks.workspace = true
 maestro-names.workspace = true
 maestro-protocol.workspace = true
 serde.workspace = true

crates/maestro-daemon/src/activity.rs

@@ -15,6 +15,44 @@ use maestro_protocol::ActivityState;
 /// Active↔Idle. This window *is* the debounce the issue calls for.
 pub const ACTIVE_WINDOW: Duration = Duration::from_secs(3);
 
+/// How long an agent-reported state (#105) stays in force before inference
+/// resumes. Long enough for a working agent's heartbeat to hold between
+/// reports, short enough that an agent dying mid-run cannot pin its session
+/// at `Error` forever.
+pub const REPORT_TTL: Duration = Duration::from_secs(300);
+
+/// Server-side cap (#105) on a reported `detail`, in characters. The meta
+/// line renders it inline, so an unbounded string would own the whole card.
+pub const MAX_REPORT_DETAIL_CHARS: usize = 256;
+
+/// An agent-reported activity state (#105) still within its TTL. While one
+/// is [`Self::in_force`], it outranks [`decide`]'s inference; when it
+/// lapses, inference resumes and any reported detail is cleared with it.
+#[derive(Debug, Clone)]
+pub struct ReportedActivity {
+    pub state: ActivityState,
+    pub expires_at: std::time::Instant,
+}
+
+impl ReportedActivity {
+    pub fn new(state: ActivityState, ttl: Duration) -> Self {
+        Self {
+            state,
+            expires_at: std::time::Instant::now() + ttl,
+        }
+    }
+
+    pub fn in_force(&self, now: std::time::Instant) -> bool {
+        now < self.expires_at
+    }
+}
+
+/// Cap a reported detail to [`MAX_REPORT_DETAIL_CHARS`] characters,
+/// char-boundary safe.
+pub fn truncate_detail(detail: Option<String>) -> Option<String> {
+    detail.map(|d| d.chars().take(MAX_REPORT_DETAIL_CHARS).collect())
+}
+
 /// Combine the observed signals into an [`ActivityState`]:
 /// recent output ⇒ `Active`; else blocked on a terminal read ⇒ `AwaitingInput`;
 /// else `Idle`.
@@ -59,4 +97,25 @@ mod tests {
             ActivityState::Idle
         );
     }
+
+    #[test]
+    fn report_is_in_force_until_exactly_its_expiry() {
+        let ttl = Duration::from_secs(300);
+        let report = ReportedActivity::new(ActivityState::Error, ttl);
+        assert!(report.in_force(report.expires_at - Duration::from_millis(1)));
+        assert!(!report.in_force(report.expires_at));
+    }
+
+    #[test]
+    fn detail_truncates_to_the_cap_without_panic_on_multibyte_input() {
+        let long = "é".repeat(MAX_REPORT_DETAIL_CHARS + 10);
+        let capped = truncate_detail(Some(long)).unwrap();
+        assert_eq!(capped.chars().count(), MAX_REPORT_DETAIL_CHARS);
+
+        assert_eq!(truncate_detail(None), None);
+        assert_eq!(
+            truncate_detail(Some("short".into())).as_deref(),
+            Some("short")
+        );
+    }
 }

crates/maestro-daemon/src/cli.rs

@@ -47,6 +47,20 @@ async fn run(config_override: Option<PathBuf>) -> Result<(), Box<dyn Error>> {
     let _ = default_state_dir();
     std::fs::create_dir_all(config.sidecar_dir())?;
     std::fs::create_dir_all(config.fifo_dir())?;
+
+    // First-start hook auto-install (#106). Best-effort, before serving: a
+    // session spawned right away should already carry the hook.
+    if config.hooks_auto_install {
+        match crate::hooks::auto_install(&config.home_dir) {
+            crate::hooks::AutoInstallOutcome::Installed => {
+                tracing::info!("installed claude-code activity hook (#106)");
+            }
+            crate::hooks::AutoInstallOutcome::Failed => {
+                tracing::warn!("hooks auto-install failed; run `maestro hooks install` manually");
+            }
+            _ => {}
+        }
+    }
     // No worktree dir to pre-create: without an override the worktrees live
     // under their base repos, created on demand (#56).
 
@@ -73,6 +87,9 @@ async fn run(config_override: Option<PathBuf>) -> Result<(), Box<dyn Error>> {
     // 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());
+    // Spawned sessions learn where to report back (#103). Derived from the
+    // configured bind address; set before any spawn can happen.
+    manager.set_daemon_url(format!("http://{}", config.bind_addr));
 
     let recovered = manager.recover().await?;
     tracing::info!(recovered, "adopted existing tmux sessions");

crates/maestro-daemon/src/config.rs

@@ -88,6 +88,10 @@ pub struct DaemonConfig {
     /// Project-discovery depth (#54): `[spawn].project_scan_depth`, default
     /// [`DEFAULT_PROJECT_SCAN_DEPTH`].
     pub project_scan_depth: u32,
+    /// Whether the daemon installs the Claude Code activity hook on first
+    /// start when none is present (#106): `[hooks].auto_install`, default
+    /// `true`.
+    pub hooks_auto_install: bool,
 }
 
 impl DaemonConfig {
@@ -197,6 +201,7 @@ pub fn load_config(path: &Path, env: EnvOverrides) -> Result<DaemonConfig, Confi
         spawn_presets,
         project_roots,
         project_scan_depth,
+        hooks_auto_install: file.hooks.auto_install(),
     })
 }
 
@@ -233,6 +238,27 @@ pub fn system_hostname() -> String {
 mod tests {
     use super::*;
 
+    #[test]
+    fn hooks_auto_install_defaults_true_and_is_opt_out() {
+        let dir = tempfile::tempdir().unwrap();
+        let path = dir.path().join("config.toml");
+
+        std::fs::write(&path, "").unwrap();
+        let cfg = load_config(&path, EnvOverrides::default()).unwrap();
+        assert!(cfg.hooks_auto_install);
+
+        std::fs::write(
+            &path,
+            r#"
+[hooks]
+auto_install = false
+"#,
+        )
+        .unwrap();
+        let cfg = load_config(&path, EnvOverrides::default()).unwrap();
+        assert!(!cfg.hooks_auto_install);
+    }
+
     #[test]
     fn empty_file_defaults_everything() {
         let dir = tempfile::tempdir().unwrap();

crates/maestro-daemon/src/hooks.rs

@@ -0,0 +1,76 @@
+//! First-start hook auto-install (#106).
+//!
+//! The daemon runs [`auto_install`] once at startup: when the user's
+//! `~/.claude/settings.json` carries no maestro hook yet (and
+//! `[hooks].auto_install` hasn't opted out — checked by the caller), the same
+//! installer `maestro hooks install` uses writes it. Best-effort: a failure is
+//! warned about and never blocks startup. The same global hook serves every
+//! Claude Code session on the machine, so nothing here targets repositories
+//! or worktrees.
+
+use std::path::Path;
+
+/// Install the Claude Code activity hook for `home_dir` unless one is already
+/// present or the home dir is unresolvable (`""`). Returns what happened.
+pub fn auto_install(home_dir: &str) -> AutoInstallOutcome {
+    if home_dir.is_empty() {
+        return AutoInstallOutcome::Skipped;
+    }
+    let settings = maestro_hooks::settings_path(Path::new(home_dir));
+    if maestro_hooks::is_installed(&settings) {
+        return AutoInstallOutcome::AlreadyPresent;
+    }
+    match maestro_hooks::install_for_home(Path::new(home_dir)) {
+        Ok(_) => AutoInstallOutcome::Installed,
+        Err(e) => {
+            tracing::warn!(error = %e, "hooks auto-install failed (non-fatal)");
+            AutoInstallOutcome::Failed
+        }
+    }
+}
+
+/// What [`auto_install`] did, so callers can log and tests can assert.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum AutoInstallOutcome {
+    Installed,
+    AlreadyPresent,
+    Failed,
+    Skipped,
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    /// Everything happens under a temp `$HOME`; the developer's own
+    /// `~/.claude/settings.json` is never read or written.
+    #[test]
+    fn installs_when_settings_carry_no_maestro_hook() {
+        let dir = tempfile::tempdir().unwrap();
+        let outcome = auto_install(dir.path().to_str().unwrap());
+        assert_eq!(outcome, AutoInstallOutcome::Installed);
+        let settings = dir.path().join(".claude/settings.json");
+        assert!(maestro_hooks::is_installed(&settings));
+    }
+
+    #[test]
+    fn second_start_is_a_noop() {
+        let dir = tempfile::tempdir().unwrap();
+        let home = dir.path().to_str().unwrap();
+        auto_install(home);
+        // A foreign edit between starts survives; presence alone skips.
+        let settings = dir.path().join(".claude/settings.json");
+        let before = std::fs::read_to_string(&settings).unwrap();
+        assert_eq!(auto_install(home), AutoInstallOutcome::AlreadyPresent);
+        assert_eq!(
+            before,
+            std::fs::read_to_string(&settings).unwrap(),
+            "already-installed settings must not be rewritten"
+        );
+    }
+
+    #[test]
+    fn unresolvable_home_is_skipped() {
+        assert_eq!(auto_install(""), AutoInstallOutcome::Skipped);
+    }
+}

crates/maestro-daemon/src/lib.rs

@@ -14,6 +14,7 @@ pub mod cli;
 pub mod config;
 pub mod dirlist;
 pub mod gitroot;
+pub mod hooks;
 pub mod local_api;
 pub mod panes;
 pub mod proc;
@@ -27,5 +28,6 @@ pub mod tmux;
 pub mod worktree;
 pub mod worktree_probe;
 
+pub use activity::MAX_REPORT_DETAIL_CHARS;
 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

@@ -15,12 +15,12 @@ use std::sync::Arc;
 use axum::extract::{Path, Query, State};
 use axum::http::StatusCode;
 use axum::response::{IntoResponse, Response};
-use axum::routing::{any, delete, get};
+use axum::routing::{any, delete, get, post};
 use axum::{Json, Router};
 use maestro_config::SpawnPreset;
 use maestro_protocol::{
-    routes, ApiError, CatalogEvent, CreateSessionRequest, DaemonInfo, GitRoot, NameBatch, Session,
+    routes, ApiError, CatalogEvent, CreateSessionRequest, DaemonInfo, GitRoot, NameBatch,
-    PROTOCOL_VERSION,
+    ReportActivityRequest, Session, PROTOCOL_VERSION,
 };
 use serde::Deserialize;
 use uuid::Uuid;
@@ -46,6 +46,7 @@ pub struct LocalApiState {
 pub fn router(state: LocalApiState) -> Router {
     Router::new()
         .route(routes::SESSIONS, get(list_sessions).post(create_session))
+        .route(routes::patterns::SESSION_ACTIVITY, post(report_activity))
         .route(routes::patterns::SESSION, delete(kill_session))
         .route(routes::DIRS, get(list_dir))
         .route(routes::RECENT_DIRS, get(recent_dirs))
@@ -318,6 +319,29 @@ async fn reclaim_worktree(State(s): State<LocalApiState>, Path(id): Path<Uuid>)
     }
 }
 
+/// `POST /api/sessions/:id/activity` (#105): an agent reports its own state.
+/// The report holds above the daemon's inference for a TTL, then inference
+/// resumes — an agent that dies mid-run cannot pin its session at `Error`
+/// forever. Unknown session is 404; an unknown state value is rejected by the
+/// JSON decoder (422) rather than coerced. Answers `204 No Content`.
+async fn report_activity(
+    State(s): State<LocalApiState>,
+    Path(id): Path<Uuid>,
+    Json(body): Json<ReportActivityRequest>,
+) -> Response {
+    match s.manager.report_activity(id, body.state, body.detail).await {
+        Ok(()) => 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(),
+            )
+        }
+    }
+}
+
 fn error_response(status: StatusCode, code: &str, message: &str) -> Response {
     (status, Json(ApiError::new(code, message))).into_response()
 }

crates/maestro-daemon/src/session.rs

@@ -57,6 +57,16 @@ pub struct SessionRecord {
     /// fall back to a probe.
     pub worktree_branch: Option<String>,
     pub bridge: PtyBridge,
+    /// Agent-reported activity (#105) still within its TTL. While in force it
+    /// outranks the activity pass's own inference; when it lapses, inference
+    /// resumes and [`Session::activity_detail`] is cleared with it. This
+    /// field is daemon-local bookkeeping only — it never rides the wire.
+    pub reported_activity: Option<crate::activity::ReportedActivity>,
+    /// Flipped once the natural-exit settle step (#82) has been applied or
+    /// refused for this session. `Dead` is observable before settling ends
+    /// (#115), so this is the observable that says its outcomes are safe to
+    /// assert on. Daemon-local bookkeeping; never rides the wire.
+    pub settled: bool,
 }
 
 #[derive(Debug, thiserror::Error)]
@@ -131,6 +141,14 @@ struct Inner {
     /// 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>,
+    /// The daemon's own HTTP base URL (#103), exported to spawned sessions as
+    /// `MAESTRO_URL`. `None` when unknown — those sessions simply don't get
+    /// the variable. A mutex because the runner sets it after construction,
+    /// possibly while clones are already serving.
+    daemon_url: std::sync::Mutex<Option<String>>,
+    /// TTL an agent-reported activity state (#105) stays in force. A const in
+    /// production; overridable for tests that watch the lapse happen.
+    report_ttl: Duration,
     sessions: Mutex<HashMap<Uuid, SessionRecord>>,
     events: broadcast::Sender<CatalogEvent>,
 }
@@ -170,6 +188,8 @@ impl SessionManager {
                 replay_bytes,
                 spawn_history: None,
                 retained: None,
+                daemon_url: std::sync::Mutex::new(None),
+                report_ttl: crate::activity::REPORT_TTL,
                 sessions: Mutex::new(HashMap::new()),
                 events,
             }),
@@ -202,6 +222,23 @@ impl SessionManager {
         self
     }
 
+    /// Override the agent-report TTL (#105). Tests pass a short one to watch
+    /// inference resume without waiting out [`crate::activity::REPORT_TTL`].
+    pub fn with_activity_report_ttl(mut self, ttl: Duration) -> Self {
+        let inner = Arc::get_mut(&mut self.inner)
+            .expect("with_activity_report_ttl must be called before the SessionManager is cloned");
+        inner.report_ttl = ttl;
+        self
+    }
+
+    /// Set the daemon's own HTTP base URL (#103), exported to every session
+    /// spawned afterwards as `MAESTRO_URL`. Unlike the `with_*` builders this
+    /// is a plain setter: the daemon runner learns its bound address after
+    /// construction, and clones may already exist by then.
+    pub fn set_daemon_url(&self, url: String) {
+        *self.inner.daemon_url.lock().expect("daemon_url mutex") = Some(url);
+    }
+
     /// 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> {
@@ -262,6 +299,17 @@ impl SessionManager {
         sessions.get(&id).map(|r| r.session.status)
     }
 
+    /// Whether the natural-exit settle step (#82) has finished for this
+    /// session: `Some(true)` once applied or refused, `Some(false)` while
+    /// still pending, `None` if the session is unknown. `Dead` is observable
+    /// before settling ends (#115), so anything asserting on a dead
+    /// session's worktree waits on this rather than inferring settle
+    /// completion from its side effects.
+    pub async fn is_settled(&self, id: Uuid) -> Option<bool> {
+        let sessions = self.inner.sessions.lock().await;
+        sessions.get(&id).map(|r| r.settled)
+    }
+
     /// Spawn a new session. On success returns the freshly-created `Session`.
     pub async fn create(&self, req: CreateSessionRequest) -> Result<Session, SessionError> {
         let (effective_cwd, worktree_path, worktree_base_repo) = match &req.worktree {
@@ -278,7 +326,11 @@ impl SessionManager {
                     self.inner.worktree_mgr.add_existing(base_repo, branch)
                 }
                 .map_err(SessionError::Worktree)?;
-                (path.clone(), Some(path), Some(base_repo.clone()))
+                // Record the repository, not whatever the request named: a
+                // spawn from inside a linked worktree passes that worktree as
+                // `base_repo`, and clients group sessions by this path (#99).
+                let repo = crate::worktree::main_checkout_of(base_repo);
+                (path.clone(), Some(path), Some(repo))
             }
             None => (req.cwd.clone(), None, None),
         };
@@ -300,7 +352,7 @@ impl SessionManager {
                     return Err(e.into());
                 }
             };
-        let session_env = match sanitize_env(&req.env) {
+        let mut session_env = match sanitize_env(&req.env) {
             Ok(env) => env,
             Err(e) => {
                 let _ = std::fs::remove_file(&fifo_path);
@@ -308,6 +360,19 @@ impl SessionManager {
                 return Err(e);
             }
         };
+        // Identity + reporting target for the in-session hook (#106). Ours
+        // win over whatever the request carried, so a client cannot spoof
+        // another session's identity (#103).
+        session_env.insert("MAESTRO_SESSION_ID".into(), id.to_string());
+        if let Some(url) = self
+            .inner
+            .daemon_url
+            .lock()
+            .expect("daemon_url mutex")
+            .clone()
+        {
+            session_env.insert("MAESTRO_URL".into(), url);
+        }
         let spawned = {
             let tmux = self.inner.tmux.clone();
             let cwd = effective_cwd.clone();
@@ -348,7 +413,9 @@ impl SessionManager {
             // activity watcher refines `foreground`/`activity` on its next tick.
             foreground: None,
             activity: ActivityState::Active,
+            activity_detail: None,
             last_activity_at: Utc::now(),
+            activity_since: chrono::Utc::now(),
 
             current_cwd: None,
             // The watcher fills this in on its first blocked-work pass; a
@@ -377,6 +444,8 @@ impl SessionManager {
                     worktree_base_repo,
                     worktree_branch: req.worktree.as_ref().map(|w| w.branch.clone()),
                     bridge,
+                    reported_activity: None,
+                    settled: false,
                 },
             );
         }
@@ -565,9 +634,14 @@ impl SessionManager {
                     status: SessionStatus::Running,
                     created_at: Utc::now(),
                     // Activity is unknown on adoption; the watcher fills it in.
+                    // #104: the restart also resets the activity clock to now —
+                    // accepted, since the daemon cannot know how long a
+                    // recovered session had already been sitting idle.
                     foreground: None,
                     activity: ActivityState::Idle,
+                    activity_detail: None,
                     last_activity_at: Utc::now(),
+                    activity_since: chrono::Utc::now(),
 
                     current_cwd: None,
                     blocked_work: None,
@@ -599,6 +673,8 @@ impl SessionManager {
                     // recovered session probes git for it at retain time.
                     worktree_branch: None,
                     bridge,
+                    reported_activity: None,
+                    settled: false,
                 },
             );
             let _ = self
@@ -639,6 +715,47 @@ impl SessionManager {
             .await
             .map_err(SessionError::Tmux)
     }
+
+    /// Accept an agent-reported activity state (#105), the only path that can
+    /// produce `ActivityState::Error`. The report outranks the activity pass's
+    /// own inference until its TTL lapses — so an agent that dies mid-run
+    /// cannot pin its session at `Error` forever. An unknown session is
+    /// [`SessionError::NotFound`]; the reported `detail` is capped
+    /// server-side.
+    ///
+    /// A report that changes the effective state restarts `activity_since`
+    /// (#104's clock); re-reporting an unchanged state only extends the TTL
+    /// and stays silent on the event stream at steady state.
+    pub async fn report_activity(
+        &self,
+        id: Uuid,
+        state: ActivityState,
+        detail: Option<String>,
+    ) -> Result<(), SessionError> {
+        let updated = {
+            let mut sessions = self.inner.sessions.lock().await;
+            let rec = sessions.get_mut(&id).ok_or(SessionError::NotFound(id))?;
+            let detail = crate::activity::truncate_detail(detail);
+            let changed = rec.session.activity != state || rec.session.activity_detail != detail;
+            if rec.session.activity != state {
+                rec.session.activity_since = Utc::now();
+            }
+            rec.session.activity = state;
+            rec.session.activity_detail = detail;
+            rec.reported_activity = Some(crate::activity::ReportedActivity::new(
+                state,
+                self.inner.report_ttl,
+            ));
+            changed.then(|| rec.session.clone())
+        };
+        if let Some(session) = updated {
+            let _ = self
+                .inner
+                .events
+                .send(CatalogEvent::SessionUpdated { session });
+        }
+        Ok(())
+    }
 }
 
 /// Run a blocking `tmux` subprocess call on the blocking thread pool so it
@@ -809,8 +926,22 @@ async fn run_activity_pass(inner: &Arc<Inner>) {
             let Some(rec) = sessions.get_mut(&id) else {
                 continue;
             };
+            // #105: an agent report lapses at its TTL — drop it and its
+            // detail so this tick's inference takes over again.
+            if let Some(report) = &rec.reported_activity {
+                if !report.in_force(std::time::Instant::now()) {
+                    rec.reported_activity = None;
+                    rec.session.activity_detail = None;
+                }
+            }
             let idle = rec.bridge.idle_for();
-            let activity = crate::activity::decide(idle, awaiting);
+            // #105: while a report is in force it supplies the state and
+            // nothing here may overwrite it; only an unreported session is
+            // decided by inference.
+            let activity = match &rec.reported_activity {
+                Some(report) => report.state,
+                None => crate::activity::decide(idle, awaiting),
+            };
             let foreground = Some(pane.command.clone());
             // The pane's live cwd, drives the dir-based session tree; empty means
             // tmux reported none.
@@ -824,6 +955,12 @@ async fn run_activity_pass(inner: &Arc<Inner>) {
             {
                 None
             } else {
+                // #104: stamp only when the state itself changed — never on
+                // foreground/cwd-only diffs, and never every tick, or the
+                // sidebar's duration would reset continuously and read zero.
+                if rec.session.activity != activity {
+                    rec.session.activity_since = Utc::now();
+                }
                 rec.session.activity = activity;
                 rec.session.foreground = foreground;
                 rec.session.current_cwd = current_cwd;
@@ -950,6 +1087,14 @@ async fn mark_session_dead(inner: &Arc<Inner>, id: Uuid) {
             }
         }
     }
+    // Settle has now been applied or refused either way (#115): from here on
+    // its outcomes are safe to observe.
+    {
+        let mut sessions = inner.sessions.lock().await;
+        if let Some(record) = sessions.get_mut(&id) {
+            record.settled = true;
+        }
+    }
 
     let _ = inner.sidecar.write(&session);
     let _ = inner.events.send(CatalogEvent::SessionUpdated { session });

crates/maestro-daemon/src/tmux.rs

@@ -264,6 +264,25 @@ impl Tmux {
         check(out)
     }
 
+    /// `tmux show-environment -t maestro-<id>`, parsed into KEY=VALUE pairs.
+    /// Test-facing view of what a spawned session actually inherits.
+    pub fn show_environment(&self, id: Uuid) -> Result<BTreeMap<String, String>, TmuxError> {
+        let name = session_name(id);
+        let out = self
+            .cmd()
+            .args(["show-environment", "-t", &name])
+            .output()?;
+        check(out.clone())?;
+        let stdout = String::from_utf8_lossy(&out.stdout);
+        let mut env = BTreeMap::new();
+        for line in stdout.lines() {
+            if let Some((k, v)) = line.split_once('=') {
+                env.insert(k.to_string(), v.to_string());
+            }
+        }
+        Ok(env)
+    }
+
     /// `tmux kill-server`. Best-effort cleanup used mostly by tests.
     pub fn kill_server(&self) -> Result<(), TmuxError> {
         let out = self.cmd().arg("kill-server").output()?;

crates/maestro-daemon/src/worktree.rs

@@ -174,6 +174,13 @@ impl WorktreeManager {
 /// The repository's main checkout. `--git-common-dir` points at the shared
 /// `.git` for every linked worktree, so its parent is the main tree. Falls
 /// back to the input when git can't answer.
+/// The repository a path belongs to: the main checkout, even when `path` is a
+/// linked worktree. Clients group sessions by this (#99), and placement uses it
+/// so a worktree is never nested inside another.
+pub fn main_checkout_of(path: &Path) -> PathBuf {
+    main_checkout(path)
+}
+
 fn main_checkout(path: &Path) -> PathBuf {
     let out = Command::new("git")
         .arg("-C")

crates/maestro-daemon/tests/activity.rs

@@ -189,8 +189,23 @@ fn a_foreground_pipeline_whose_leader_exited_is_still_awaiting_input() {
         "never observed a foreground group whose leader had exited"
     );
 
-    assert!(
+    // The leader can be gone while the surviving stage is still setting up:
-        awaiting_input(pane.pane_pid, &pane.tty, &ProcGroups::snapshot()),
+    // `true` exits as soon as both stages are forked, before the reader has
-        "a surviving pipeline member still holds the tty"
+    // opened the tty and parked. Poll for the answer, but only accept it
-    );
+    // while the state this test exists for still holds — otherwise a shell
+    // that regained the terminal would satisfy it vacuously.
+    let deadline = std::time::Instant::now() + Duration::from_secs(5);
+    let mut holds = false;
+    while std::time::Instant::now() < deadline {
+        let groups = ProcGroups::snapshot();
+        let still_leaderless = pgrp_and_tpgid(pane.pane_pid).is_some_and(|(pgrp, tpgid)| {
+            tpgid > 0 && tpgid != pgrp && pgrp_and_tpgid(tpgid).is_none()
+        });
+        if still_leaderless && awaiting_input(pane.pane_pid, &pane.tty, &groups) {
+            holds = true;
+            break;
+        }
+        std::thread::sleep(Duration::from_millis(20));
+    }
+    assert!(holds, "a surviving pipeline member still holds the tty");
 }

crates/maestro-daemon/tests/activity_report.rs

@@ -0,0 +1,164 @@
+//! Agent-reported activity (#105): `POST /api/sessions/:id/activity`
+//! semantics at the SessionManager level — precedence over the daemon's own
+//! inference, detail handling, and lapse back to inference at the TTL.
+
+mod common;
+
+use std::sync::Arc;
+use std::time::Duration;
+
+use common::TmuxFixture;
+use maestro_daemon::sidecar::SidecarStore;
+use maestro_daemon::worktree::WorktreeManager;
+use maestro_daemon::SessionManager;
+use maestro_protocol::{ActivityState, CreateSessionRequest};
+use tempfile::TempDir;
+use tokio::time::sleep;
+use uuid::Uuid;
+
+struct Fixture {
+    manager: SessionManager,
+    _tmux: TmuxFixture,
+    _state_dir: TempDir,
+}
+
+async fn fixture(ttl: Duration) -> Fixture {
+    let tmux = TmuxFixture::new();
+    let state_dir = TempDir::new().unwrap();
+    let manager = SessionManager::new(
+        Arc::new(tmux.tmux.clone()),
+        SidecarStore::new(state_dir.path().join("sessions")),
+        WorktreeManager::new(None),
+        state_dir.path().join("fifos"),
+    )
+    .with_activity_report_ttl(ttl);
+    Fixture {
+        manager,
+        _tmux: tmux,
+        _state_dir: state_dir,
+    }
+}
+
+async fn spawn_sleeping(manager: &SessionManager) -> Uuid {
+    manager
+        .create(CreateSessionRequest {
+            cwd: "/tmp".into(),
+            command: "sleep 60".into(),
+            env: Default::default(),
+            metadata: Default::default(),
+            worktree: None,
+        })
+        .await
+        .unwrap()
+        .id
+}
+
+async fn observed(manager: &SessionManager, id: Uuid) -> maestro_protocol::Session {
+    manager
+        .snapshot()
+        .await
+        .into_iter()
+        .find(|s| s.id == id)
+        .expect("session still tracked")
+}
+
+#[tokio::test]
+async fn report_on_unknown_session_is_not_found() {
+    let fx = fixture(Duration::from_secs(300)).await;
+    let err = fx
+        .manager
+        .report_activity(Uuid::new_v4(), ActivityState::Idle, None)
+        .await
+        .unwrap_err();
+    assert!(matches!(err, maestro_daemon::SessionError::NotFound(_)));
+}
+
+#[tokio::test]
+async fn report_sets_error_state_and_detail() {
+    let fx = fixture(Duration::from_secs(300)).await;
+    let id = spawn_sleeping(&fx.manager).await;
+
+    fx.manager
+        .report_activity(
+            id,
+            ActivityState::Error,
+            Some("cargo build failed: link error".into()),
+        )
+        .await
+        .unwrap();
+
+    let s = observed(&fx.manager, id).await;
+    assert_eq!(s.activity, ActivityState::Error);
+    assert_eq!(
+        s.activity_detail.as_deref(),
+        Some("cargo build failed: link error")
+    );
+}
+
+#[tokio::test]
+async fn replacing_a_report_replaces_both_state_and_detail() {
+    let fx = fixture(Duration::from_secs(300)).await;
+    let id = spawn_sleeping(&fx.manager).await;
+
+    fx.manager
+        .report_activity(id, ActivityState::Error, Some("first failure".into()))
+        .await
+        .unwrap();
+    fx.manager
+        .report_activity(
+            id,
+            ActivityState::AwaitingInput,
+            Some("needs approval".into()),
+        )
+        .await
+        .unwrap();
+
+    let s = observed(&fx.manager, id).await;
+    assert_eq!(s.activity, ActivityState::AwaitingInput);
+    assert_eq!(s.activity_detail.as_deref(), Some("needs approval"));
+}
+
+#[tokio::test]
+async fn detail_is_capped_server_side() {
+    let fx = fixture(Duration::from_secs(300)).await;
+    let id = spawn_sleeping(&fx.manager).await;
+
+    let long = "x".repeat(10_000);
+    fx.manager
+        .report_activity(id, ActivityState::Error, Some(long))
+        .await
+        .unwrap();
+
+    let s = observed(&fx.manager, id).await;
+    let detail = s.activity_detail.expect("detail present");
+    assert_eq!(
+        detail.chars().count(),
+        maestro_daemon::MAX_REPORT_DETAIL_CHARS
+    );
+}
+
+#[tokio::test]
+async fn reported_state_survives_watcher_ticks_until_the_ttl_then_inference_resumes() {
+    let fx = fixture(Duration::from_millis(150)).await;
+    let id = spawn_sleeping(&fx.manager).await;
+    fx.manager.start_liveness_watcher(Duration::from_millis(50));
+
+    fx.manager
+        .report_activity(id, ActivityState::Error, Some("agent died mid-run".into()))
+        .await
+        .unwrap();
+
+    // Several watcher ticks inside the TTL: nothing infers `Error`, so the
+    // report must hold above inference.
+    sleep(Duration::from_millis(80)).await;
+    let s = observed(&fx.manager, id).await;
+    assert_eq!(s.activity, ActivityState::Error);
+    assert_eq!(s.activity_detail.as_deref(), Some("agent died mid-run"));
+
+    // After the TTL lapses, inference resumes and the detail goes with it.
+    common::wait_for_async(Duration::from_secs(5), || async {
+        let s = observed(&fx.manager, id).await;
+        s.activity != ActivityState::Error && s.activity_detail.is_none()
+    })
+    .await;
+}

crates/maestro-daemon/tests/local_api.rs

@@ -346,6 +346,109 @@ async fn delete_owned_session_kills_it() {
     assert!(!h.manager.has(session.id).await);
 }
 
+/// Spawn a session through the manager and return its id.
+async fn spawn_via_manager(h: &Harness) -> Uuid {
+    h.manager
+        .create(CreateSessionRequest {
+            cwd: "/tmp".into(),
+            command: "sleep 60".into(),
+            env: HashMap::new(),
+            metadata: HashMap::new(),
+            worktree: None,
+        })
+        .await
+        .unwrap()
+        .id
+}
+
+/// The agent activity endpoint on the wire (#105): a report lands in the
+/// session snapshot with its detail.
+#[tokio::test]
+async fn post_activity_reports_error_with_detail() {
+    let h = spawn("naps-laptop").await;
+    let id = spawn_via_manager(&h).await;
+
+    let resp = reqwest::Client::new()
+        .post(url(h.addr, &format!("/api/sessions/{id}/activity")))
+        .json(&serde_json::json!({
+            "state": "Error",
+            "detail": "cargo build failed"
+        }))
+        .send()
+        .await
+        .unwrap();
+    assert_eq!(resp.status(), reqwest::StatusCode::NO_CONTENT);
+
+    let sessions: Vec<Session> = reqwest::get(url(h.addr, "/api/sessions"))
+        .await
+        .unwrap()
+        .json()
+        .await
+        .unwrap();
+    let s = sessions.iter().find(|s| s.id == id).unwrap();
+    assert_eq!(s.activity, maestro_protocol::ActivityState::Error);
+    assert_eq!(s.activity_detail.as_deref(), Some("cargo build failed"));
+}
+
+#[tokio::test]
+async fn post_activity_to_unknown_session_returns_404() {
+    let h = spawn("naps-laptop").await;
+    let resp = reqwest::Client::new()
+        .post(url(
+            h.addr,
+            &format!("/api/sessions/{}/activity", Uuid::new_v4()),
+        ))
+        .json(&serde_json::json!({ "state": "Idle" }))
+        .send()
+        .await
+        .unwrap();
+    assert_eq!(resp.status(), reqwest::StatusCode::NOT_FOUND);
+}
+
+/// Unknown state values are rejected rather than coerced (#105).
+#[tokio::test]
+async fn post_activity_rejects_an_unknown_state_value() {
+    let h = spawn("naps-laptop").await;
+    let id = spawn_via_manager(&h).await;
+
+    let resp = reqwest::Client::new()
+        .post(url(h.addr, &format!("/api/sessions/{id}/activity")))
+        .json(&serde_json::json!({ "state": "Teleported" }))
+        .send()
+        .await
+        .unwrap();
+    assert!(resp.status().is_client_error(), "got {}", resp.status());
+}
+
+#[tokio::test]
+async fn post_activity_caps_an_overlong_detail_server_side() {
+    let h = spawn("naps-laptop").await;
+    let id = spawn_via_manager(&h).await;
+
+    let resp = reqwest::Client::new()
+        .post(url(h.addr, &format!("/api/sessions/{id}/activity")))
+        .json(&serde_json::json!({
+            "state": "Error",
+            "detail": "x".repeat(10_000)
+        }))
+        .send()
+        .await
+        .unwrap();
+    assert_eq!(resp.status(), reqwest::StatusCode::NO_CONTENT);
+
+    let sessions: Vec<Session> = reqwest::get(url(h.addr, "/api/sessions"))
+        .await
+        .unwrap()
+        .json()
+        .await
+        .unwrap();
+    let s = sessions.iter().find(|s| s.id == id).unwrap();
+    assert_eq!(
+        s.activity_detail.as_ref().map(|d| d.chars().count()),
+        Some(maestro_daemon::MAX_REPORT_DETAIL_CHARS)
+    );
+}
+
 /// The kill guard on the wire (#79): `DELETE /api/sessions/:id` answers 409
 /// with the structured breakdown, and the session keeps running.
 #[tokio::test]

crates/maestro-daemon/tests/session_decisions.rs

@@ -30,6 +30,24 @@ impl Fx {
         Self::with_sidecar_dir(|tmp| tmp.join("sidecars"))
     }
 
+    /// Variant whose manager knows the daemon's own base URL (#103), the way
+    /// the production runner wires it from `[daemon].bind_addr`.
+    fn with_daemon_url(url: &str) -> Self {
+        let fx = Self::new();
+        fx.manager.set_daemon_url(url.to_string());
+        fx
+    }
+
+    /// The env map of the (single, expected) spawn call.
+    fn spawned_env(&self) -> BTreeMap<String, String> {
+        let calls = self.fake.calls();
+        let Some(Call::NewSessionPiped { env, .. }) = calls.first() else {
+            panic!("expected a spawn call, got {calls:?}");
+        };
+        assert_eq!(calls.len(), 1, "expected exactly one spawn: {calls:?}");
+        env.clone()
+    }
+
     fn with_sidecar_dir(pick: impl Fn(&std::path::Path) -> PathBuf) -> Self {
         let tmp = TempDir::new().expect("tempdir");
         let fake = Arc::new(FakePanes::new());
@@ -261,16 +279,23 @@ async fn requested_env_reaches_tmux() {
 
     fx.manager.create(req).await.expect("create");
 
+    let spawned = match fx.fake.calls().first() {
+        Some(Call::NewSessionPiped { env, .. }) => env.clone(),
+        other => panic!("expected a spawn call, got {other:?}"),
+    };
+    let id = spawned
+        .get("MAESTRO_SESSION_ID")
+        .expect("spawn must export MAESTRO_SESSION_ID (#103)")
+        .clone();
+    // The daemon-owned variable rides alongside whatever was requested.
     let want: BTreeMap<String, String> = [
         ("EMPTY".to_string(), String::new()),
         ("FOO".to_string(), "bar".to_string()),
+        ("MAESTRO_SESSION_ID".to_string(), id),
     ]
     .into_iter()
     .collect();
-    match fx.fake.calls().first() {
+    assert_eq!(&spawned, &want);
-        Some(Call::NewSessionPiped { env, .. }) => assert_eq!(env, &want),
-        other => panic!("expected a spawn call, got {other:?}"),
-    }
 }
 
 #[tokio::test]
@@ -338,6 +363,9 @@ async fn activity_pass_emits_updated_only_when_something_changed() {
     // Still inside `activity::ACTIVE_WINDOW` (3s) since the spawn, so the
     // change here is `foreground`, not the activity state.
     assert_eq!(updated.activity, ActivityState::Active);
+    // A foreground/cwd-only change is not a state transition (#104): the
+    // sidebar's duration must keep counting from the original stamp.
+    assert_eq!(updated.activity_since, session.activity_since);
 
     // Drain anything already queued, then confirm a steady pane stays quiet.
     // Stays well inside the 3s window, so no Active -> Idle transition either.
@@ -349,6 +377,70 @@ async fn activity_pass_emits_updated_only_when_something_changed() {
     );
 }
 
+/// The sidebar's duration (#104) is time in the *current* state, so
+/// `activity_since` is stamped exactly when the decided state differs from
+/// the stored one — once per transition. Stamping it every tick would make
+/// the duration permanently read zero.
+#[tokio::test]
+async fn activity_transition_stamps_activity_since_once_per_transition() {
+    let fx = Fx::new();
+    let session = fx
+        .manager
+        .create(fx.request("sleep 300"))
+        .await
+        .expect("create");
+    fx.fake.set_pane_info(
+        session.id,
+        PaneInfo {
+            // Nothing reads from this pid: `awaiting_input` is deterministically
+            // false, so past `ACTIVE_WINDOW` the session decides as Idle.
+            pane_pid: i32::MAX,
+            command: "sleep".into(),
+            tty: "/dev/null".into(),
+            current_path: String::new(),
+        },
+    );
+    let mut events = fx.manager.events();
+    fx.manager.start_liveness_watcher(Duration::from_millis(25));
+
+    let idle = wait_for_activity(&fx.manager, session.id, ActivityState::Idle).await;
+    assert!(
+        idle.activity_since >= session.activity_since + chrono::Duration::seconds(2),
+        "the Active -> Idle transition must stamp a fresh activity_since \
+         (spawn stamp {:?}, transition stamp {:?})",
+        session.activity_since,
+        idle.activity_since
+    );
+
+    // Steady Idle across many more ticks must not re-stamp — no further
+    // SessionUpdated at all, or the sidebar clock would keep resetting.
+    while events.try_recv().is_ok() {}
+    tokio::time::sleep(Duration::from_millis(300)).await;
+    assert!(
+        matches!(events.try_recv(), Err(TryRecvError::Empty)),
+        "a steady state must not re-emit (and re-stamp) on every tick"
+    );
+}
+
+async fn wait_for_activity(
+    manager: &SessionManager,
+    id: uuid::Uuid,
+    want: ActivityState,
+) -> maestro_protocol::Session {
+    let deadline = tokio::time::Instant::now() + Duration::from_secs(6);
+    loop {
+        if tokio::time::Instant::now() >= deadline {
+            panic!("timed out waiting for {id} to become {want:?}");
+        }
+        if let Some(s) = manager.snapshot().await.into_iter().find(|s| s.id == id) {
+            if s.activity == want {
+                return s;
+            }
+        }
+        tokio::time::sleep(Duration::from_millis(20)).await;
+    }
+}
+
 async fn wait_for_updated(
     events: &mut tokio::sync::broadcast::Receiver<CatalogEvent>,
 ) -> maestro_protocol::Session {
@@ -396,3 +488,70 @@ fn attaching_spawn_history_after_cloning_panics() {
         7,
     ));
 }
+
+/// Every tmux-spawned session learns who it is (#103): its own UUID under
+/// `MAESTRO_SESSION_ID`, so the reporting hook in #106 can name the session
+/// it is running inside.
+#[tokio::test]
+async fn spawn_exports_maestro_session_id() {
+    let fx = Fx::new();
+    let s = fx.manager.create(fx.request("bash")).await.expect("create");
+
+    let env = fx.spawned_env();
+    assert_eq!(
+        env.get("MAESTRO_SESSION_ID").map(String::as_str),
+        Some(&s.id.to_string()[..]),
+        "MAESTRO_SESSION_ID must be the session's UUID, got {env:?}"
+    );
+}
+
+/// The hook also needs to know where to report to: `MAESTRO_URL` carries the
+/// daemon's base URL derived from `[daemon].bind_addr` (#103).
+#[tokio::test]
+async fn spawn_exports_maestro_url_when_the_daemon_is_wired() {
+    let fx = Fx::with_daemon_url("http://127.0.0.1:7070");
+    fx.manager.create(fx.request("bash")).await.expect("create");
+
+    let env = fx.spawned_env();
+    assert_eq!(
+        env.get("MAESTRO_URL").map(String::as_str),
+        Some("http://127.0.0.1:7070"),
+        "MAESTRO_URL must be the daemon's base URL, got {env:?}"
+    );
+}
+
+/// Without a wired URL (tests, or a caller that never set one) only the
+/// session id is injected — an empty or bogus `MAESTRO_URL` would send the
+/// #106 hook's reports nowhere useful.
+#[tokio::test]
+async fn spawn_omits_maestro_url_when_not_wired() {
+    let fx = Fx::new();
+    fx.manager.create(fx.request("bash")).await.expect("create");
+
+    let env = fx.spawned_env();
+    assert!(
+        !env.contains_key("MAESTRO_URL"),
+        "MAESTRO_URL must be absent when no daemon URL is known, got {env:?}"
+    );
+}
+
+/// The daemon-owned variables win over anything the spawner sent: a client
+/// cannot spoof another session's identity.
+#[tokio::test]
+async fn spawn_overrides_client_supplied_maestro_variables() {
+    let fx = Fx::with_daemon_url("http://127.0.0.1:7070");
+    let mut req = fx.request("bash");
+    req.env.insert(
+        "MAESTRO_SESSION_ID".into(),
+        "00000000-0000-0000-0000-000000000000".into(),
+    );
+    req.env.insert("MAESTRO_URL".into(), "http://evil:1".into());
+    let s = fx.manager.create(req).await.expect("create");
+
+    let env = fx.spawned_env();
+    assert_eq!(env.get("MAESTRO_SESSION_ID"), Some(&s.id.to_string()));
+    assert_eq!(
+        env.get("MAESTRO_URL"),
+        Some(&"http://127.0.0.1:7070".to_string())
+    );
+}

crates/maestro-daemon/tests/session_manager.rs

@@ -397,6 +397,12 @@ async fn watcher_refreshes_the_blocked_work_indicator() {
     init_bare_repo(origin.path());
     push_all_to_origin(repo.path(), origin.path());
 
+    // Subscribe before the watcher starts so every pass's emission is
+    // captured — otherwise the breakdown event can land between the
+    // snapshot observation below and the drain, and the quiet window
+    // would see it as an illegitimate re-emit.
+    let mut events = fx.manager.events();
+
     fx.manager.start_liveness_watcher_with_blocked_work(
         Duration::from_millis(50),
         Duration::from_millis(100),
@@ -418,14 +424,38 @@ async fn watcher_refreshes_the_blocked_work_indicator() {
     })
     .await;
 
-    // A steady state must not re-emit every tick (#83 change-detection).
+    // Consume through the emission that carried the breakdown (#83
-    let mut events = fx.manager.events();
+    // change-detection): the quiet window below must start after the last
+    // legitimate change, not race it into the channel.
+    loop {
+        match tokio::time::timeout(Duration::from_secs(5), events.recv()).await {
+            Ok(Ok(CatalogEvent::SessionUpdated { session }))
+                if matches!(
+                    &session.blocked_work,
+                    Some(b) if b.uncommitted_files >= 1 && b.untracked_files >= 1
+                ) =>
+            {
+                break;
+            }
+            Ok(Ok(_)) => continue,
+            _ => panic!("never saw the SessionUpdated carrying the breakdown"),
+        }
+    }
     while events.try_recv().is_ok() {}
     tokio::time::sleep(Duration::from_millis(400)).await;
-    assert!(
+    // Only a *changed* indicator counts as a re-emit (#83 change-detection).
-        !matches!(events.try_recv(), Ok(CatalogEvent::SessionUpdated { .. })),
+    // The activity pass may still legitimately announce e.g. Active→Idle
-        "an unchanged worktree must not re-emit SessionUpdated"
+    // (its debounce is time-based, not worktree-based), and its payload
-    );
+    // carries today's blocked_work unchanged.
+    while let Ok(CatalogEvent::SessionUpdated { session }) = events.try_recv() {
+        assert!(
+            matches!(
+                &session.blocked_work,
+                Some(b) if b.uncommitted_files >= 1 && b.untracked_files >= 1
+            ),
+            "an unchanged worktree must not re-emit a changed indicator"
+        );
+    }
 }
 
 /// Cleanup on kill is unconditional once the guard passes (#79): even a spec
@@ -769,6 +799,14 @@ async fn natural_exit_of_a_guarded_worktree_retains_it_in_the_store() {
         "a dirty worktree must be retained on natural exit"
     );
     // ...in the store, under the exit reason.
+    // (`Dead` is observable a moment before the settle step's store write lands.)
+    wait_for_async(Duration::from_secs(3), || async {
+        fx.retained_store()
+            .load_all()
+            .map(|all| all.len() == 1)
+            .unwrap_or(false)
+    })
+    .await;
     let all = fx.retained_store().load_all().expect("load_all");
     assert_eq!(all.len(), 1);
     assert_eq!(all[0].path, wt_path);
@@ -840,6 +878,17 @@ async fn natural_exit_of_a_pristine_worktree_removes_it() {
     })
     .await;
 
+    // (`Dead` is observable a moment before the settle step removes the tree.)
+    wait_for_async(Duration::from_secs(3), || async {
+        !wt_path.exists()
+            && fx
+                .retained_store()
+                .load_all()
+                .map(|all| all.is_empty())
+                .unwrap_or(false)
+    })
+    .await;
+
     assert!(
         !wt_path.exists(),
         "a pristine worktree leaves nothing behind"
@@ -897,6 +946,14 @@ async fn natural_exit_without_a_retained_store_destroys_nothing() {
     })
     .await;
 
+    // The settle step has been applied or refused either way — here refused,
+    // since there is no store to record the tree into. Only from this point
+    // is "the tree survived" a settled fact rather than a race (#115).
+    wait_for_async(Duration::from_secs(3), || async {
+        manager.is_settled(s.id).await == Some(true)
+    })
+    .await;
+
     assert!(
         wt_path.exists(),
         "nothing may be destroyed when it cannot be recorded"
@@ -947,3 +1004,101 @@ async fn liveness_watcher_leaves_running_sessions_alone() {
 
     fx.manager.kill(s.id, false).await.unwrap();
 }
+
+/// #99: clients group a session under `worktree.base_repo`, so that field has
+/// to name the repository even when the spawn request pointed at a linked
+/// worktree. Recording the request verbatim put the session in a folder of its
+/// own — `<repo>/worktrees/<branch>` — instead of under the repo.
+#[tokio::test]
+async fn worktree_base_repo_records_the_main_checkout_not_the_request() {
+    let fx = DaemonFixture::new();
+    let repo = TempDir::new().unwrap();
+    init_repo(repo.path());
+
+    // A linked worktree of that repo, then a spawn whose `base_repo` names it
+    // rather than the main checkout — what happens when the operator spawns
+    // from inside a worktree.
+    let first = 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/one".into(),
+                create_branch: true,
+            }),
+        })
+        .await
+        .expect("create first");
+    let inner_worktree = first.worktree.expect("first has a worktree").path;
+
+    let second = fx
+        .manager
+        .create(CreateSessionRequest {
+            cwd: inner_worktree.clone(),
+            command: "sleep 30".into(),
+            env: HashMap::new(),
+            metadata: HashMap::new(),
+            worktree: Some(WorktreeSpec {
+                base_repo: inner_worktree.clone(),
+                branch: "feat/two".into(),
+                create_branch: true,
+            }),
+        })
+        .await
+        .expect("create second");
+
+    let wt = second.worktree.expect("second has a worktree");
+    assert_eq!(
+        wt.base_repo,
+        repo.path()
+            .canonicalize()
+            .unwrap_or_else(|_| repo.path().to_path_buf()),
+        "base_repo must be the repository, not the worktree the request named",
+    );
+    assert_ne!(wt.base_repo, inner_worktree, "the worktree is not the repo");
+}
+
+/// #103: every tmux-spawned session carries the daemon's identity variables in
+/// its environment — its UUID under `MAESTRO_SESSION_ID` and the daemon's base
+/// URL under `MAESTRO_URL` — so the in-session reporting hook (#106) can find
+/// both without any out-of-band channel.
+#[tokio::test]
+async fn spawned_sessions_export_maestro_session_id_and_url() {
+    let fx = DaemonFixture::new();
+    fx.manager
+        .set_daemon_url("http://127.0.0.1:7071".to_string());
+    let cwd = TempDir::new().unwrap();
+
+    let s = fx
+        .manager
+        .create(CreateSessionRequest {
+            cwd: cwd.path().to_path_buf(),
+            command: "sleep 30".into(),
+            env: HashMap::new(),
+            metadata: HashMap::new(),
+            worktree: None,
+        })
+        .await
+        .expect("create");
+
+    let env = fx
+        .tmux
+        .tmux
+        .show_environment(s.id)
+        .expect("show-environment");
+    assert_eq!(
+        env.get("MAESTRO_SESSION_ID"),
+        Some(&s.id.to_string()),
+        "session env: {env:?}"
+    );
+    assert_eq!(
+        env.get("MAESTRO_URL"),
+        Some(&"http://127.0.0.1:7071".to_string())
+    );
+
+    fx.manager.kill(s.id, false).await.expect("kill");
+}

crates/maestro-daemon/tests/sidecar.rs

@@ -26,7 +26,9 @@ fn sample(id: Uuid) -> Session {
             .with_timezone(&Utc),
         foreground: None,
         activity: Default::default(),
+        activity_detail: None,
         last_activity_at: chrono::Utc::now(),
+        activity_since: chrono::Utc::now(),
         current_cwd: Some(PathBuf::from("/tmp/work/crates")),
         blocked_work: None,
     }

crates/maestro-hooks/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "maestro-hooks"
+version.workspace = true
+edition.workspace = true
+license.workspace = true
+repository.workspace = true
+publish.workspace = true
+description = "Agent activity hooks (#106): shipped script + idempotent settings.json installer"
+
+[dependencies]
+serde_json.workspace = true
+thiserror.workspace = true
+
+[dev-dependencies]
+tempfile.workspace = true

crates/maestro-hooks/src/lib.rs

@@ -0,0 +1,261 @@
+//! Claude Code activity hook (#106).
+//!
+//! Two halves, both shared by the `maestro hooks install` CLI subcommand and
+//! the daemon's first-start auto-install:
+//!
+//! * [`HOOK_SCRIPT`] — the hook itself, written to disk at install time. It
+//!   posts an [`ActivityState`](maestro-protocol) to
+//!   `$MAESTRO_URL/api/sessions/$MAESTRO_SESSION_ID/activity` (#105). The same
+//!   global hook runs in every Claude Code session on the machine, so it exits
+//!   0 and silently when either #103 env var is unset, and it never lets a
+//!   daemon failure escape (short curl timeout, status ignored).
+//! * [`install`] — idempotent registration of that script in
+//!   `~/.claude/settings.json`. Only entries maestro itself wrote (identified
+//!   by [`HOOK_MARKER`]) are touched; every other hook and every other field
+//!   in the file is preserved verbatim.
+
+use std::path::Path;
+
+/// Marker substring every maestro-installed hook command carries. The
+/// installer rewrites or removes exactly these entries — nothing else in the
+/// user's settings file.
+pub const HOOK_MARKER: &str = "maestro-claude-hook";
+
+/// File name of the installed script (carries [`HOOK_MARKER`]).
+pub const SCRIPT_FILE_NAME: &str = "maestro-claude-hook.sh";
+
+/// Claude Code hook event → `ActivityState` spelling posted to the daemon.
+///
+/// `PreToolUse` is what makes a session `Active` *during* a long tool call —
+/// `PostToolUse` alone only fires once it ends (#114). `StopFailure` is
+/// Claude Code's own name for "the turn ended on an API error"; there is no
+/// failure signal in `Stop` or `SessionEnd` payloads, so those never report
+/// `Error`.
+pub const HOOK_EVENTS: [(&str, &str); 5] = [
+    // Tool starting: the agent is demonstrably producing work, even if the
+    // tool itself runs for minutes.
+    ("PreToolUse", "Active"),
+    // Tool finished successfully.
+    ("PostToolUse", "Active"),
+    // Permission / idle notices: Claude is blocked on the user.
+    ("Notification", "AwaitingInput"),
+    // Turn ended: waiting on the user again.
+    ("Stop", "AwaitingInput"),
+    // Turn ended on an API error; the payload's `error` field is forwarded
+    // as the report's `detail` (#114).
+    ("StopFailure", "Error"),
+];
+
+/// The shipped hook script. POSIX sh so any `/bin/sh` works.
+pub const HOOK_SCRIPT: &str = r#"#!/bin/sh
+# Installed by maestro (#106): report Claude Code activity to its daemon.
+# Exits silently unless running inside a session maestro spawned (#103 env).
+# Event -> ActivityState mapping:
+#   PreToolUse    -> Active         (tool started; agent is working)
+#   PostToolUse   -> Active         (tool finished)
+#   Notification  -> AwaitingInput  (permission / idle notice)
+#   Stop          -> AwaitingInput  (turn ended; waiting on the user)
+#   StopFailure   -> Error          (turn ended on an API error)
+state="$1"
+[ -n "$MAESTRO_SESSION_ID" ] || exit 0
+[ -n "$MAESTRO_URL" ] || exit 0
+payload=$(cat 2>/dev/null) || true
+body="{\"state\":\"$state\"}"
+# StopFailure payloads carry the outcome in "error". Only a plain enum
+# spelling is reported as the detail — anything else (quotes, backslashes,
+# prose) would risk breaking the JSON body, and the spelling already names
+# the failure.
+detail=$(printf '%s' "$payload" | sed -n 's/.*"error"[[:space:]]*:[[:space:]]*"\([a-z_]*\)".*/\1/p')
+if [ -n "$detail" ]; then
+    body="{\"state\":\"$state\",\"detail\":\"$detail\"}"
+fi
+curl -fsS --connect-timeout 1 --max-time 2 \
+    -H 'Content-Type: application/json' \
+    -d "$body" \
+    "$MAESTRO_URL/api/sessions/$MAESTRO_SESSION_ID/activity" \
+    >/dev/null 2>&1 || true
+exit 0
+"#;
+
+#[derive(Debug, thiserror::Error)]
+pub enum HooksError {
+    #[error("io: {0}")]
+    Io(#[from] std::io::Error),
+    #[error("json: {0}")]
+    Json(#[from] serde_json::Error),
+}
+
+/// Where the script is written for a given home directory:
+/// `<home>/.local/share/maestro/maestro-claude-hook.sh`.
+pub fn script_path(home: &Path) -> std::path::PathBuf {
+    home.join(".local/share/maestro").join(SCRIPT_FILE_NAME)
+}
+
+/// The user-level Claude Code settings file for a given home directory.
+pub fn settings_path(home: &Path) -> std::path::PathBuf {
+    home.join(".claude/settings.json")
+}
+
+/// Whether `settings_path` already carries a maestro hook (#106).
+pub fn is_installed(settings_path: &Path) -> bool {
+    settings_json(settings_path)
+        .map(|root| find_maestro_commands(&root).next().is_some())
+        .unwrap_or(false)
+}
+
+/// Write [`HOOK_SCRIPT`] to `path`, executable. Parent directories are
+/// created as needed — this is always under the caller's chosen data dir,
+/// never inside a repository.
+pub fn write_script(path: &Path) -> Result<(), HooksError> {
+    if let Some(dir) = path.parent() {
+        std::fs::create_dir_all(dir)?;
+    }
+    std::fs::write(path, HOOK_SCRIPT)?;
+    #[cfg(unix)]
+    {
+        use std::os::unix::fs::PermissionsExt;
+        let mut perms = std::fs::metadata(path)?.permissions();
+        perms.set_mode(0o755);
+        std::fs::set_permissions(path, perms)?;
+    }
+    Ok(())
+}
+
+/// Install the full hook setup for `home`: write the script under
+/// `.local/share/maestro/` and register it in `.claude/settings.json`.
+/// Idempotent; returns whether anything changed on disk.
+pub fn install_for_home(home: &Path) -> Result<bool, HooksError> {
+    let script = script_path(home);
+    let settings = settings_path(home);
+    let before = std::fs::read_to_string(&settings).unwrap_or_default();
+    write_script(&script)?;
+    install(&settings, &script)?;
+    let after = std::fs::read_to_string(&settings).unwrap_or_default();
+    Ok(before != after)
+}
+
+/// Register the hook command for every event in [`HOOK_EVENTS`] in the
+/// settings file at `settings_path`. Idempotent: existing maestro entries are
+/// updated in place wherever they sit, stale ones removed, duplicates folded;
+/// every non-maestro entry and every unrelated top-level field survives.
+///
+/// Never inspects or writes anywhere but `settings_path` — callers pass the
+/// user's real home or a temp one in tests, never a repository.
+pub fn install(settings_path: &Path, script_path: &Path) -> Result<(), HooksError> {
+    let mut root = settings_json(settings_path)?;
+
+    // Strip every maestro entry wherever it currently sits, so an older
+    // install under different events is replaced rather than duplicated.
+    strip_maestro_entries(&mut root);
+
+    let hooks = ensure_object(&mut root, "hooks");
+    for (event, state) in HOOK_EVENTS {
+        let groups = ensure_array(hooks, event);
+        let mut group = serde_json::Map::new();
+        group.insert(
+            "hooks".into(),
+            serde_json::json!([{
+                "type": "command",
+                "command": format!("{} {state}", script_path.display()),
+            }]),
+        );
+        groups.push(serde_json::Value::Object(group));
+    }
+
+    write_atomic(settings_path, &root)
+}
+
+fn settings_json(path: &Path) -> Result<serde_json::Value, HooksError> {
+    match std::fs::read_to_string(path) {
+        Ok(s) => Ok(serde_json::from_str(&s)?),
+        Err(e) if e.kind() == std::io::ErrorKind::NotFound => {
+            Ok(serde_json::Value::Object(Default::default()))
+        }
+        Err(e) => Err(e.into()),
+    }
+}
+
+/// Every command string in the file belonging to a maestro hook.
+fn find_maestro_commands(root: &serde_json::Value) -> impl Iterator<Item = &str> {
+    root.get("hooks")
+        .and_then(|h| h.as_object())
+        .into_iter()
+        .flat_map(|events| events.values())
+        .filter_map(|groups| groups.as_array())
+        .flatten()
+        .filter_map(|group| group.get("hooks"))
+        .filter_map(|inner| inner.as_array())
+        .flatten()
+        .filter_map(|hook| hook.get("command"))
+        .filter_map(|cmd| cmd.as_str())
+        .filter(|cmd| cmd.contains(HOOK_MARKER))
+}
+
+/// Remove all maestro inner-hook entries from every event group, dropping
+/// groups left empty. Non-maestro siblings survive untouched.
+fn strip_maestro_entries(root: &mut serde_json::Value) {
+    let Some(events) = root.get_mut("hooks").and_then(|h| h.as_object_mut()) else {
+        return;
+    };
+    for (_, groups) in events.iter_mut() {
+        let Some(list) = groups.as_array_mut() else {
+            continue;
+        };
+        for group in list.iter_mut() {
+            let Some(inner) = group.get_mut("hooks").and_then(|h| h.as_array_mut()) else {
+                continue;
+            };
+            inner.retain(|hook| {
+                !hook
+                    .get("command")
+                    .and_then(|c| c.as_str())
+                    .is_some_and(|c| c.contains(HOOK_MARKER))
+            });
+        }
+        list.retain(|group| {
+            group
+                .get("hooks")
+                .and_then(|h| h.as_array())
+                .is_some_and(|h| !h.is_empty())
+        });
+    }
+    // An event left with no groups at all (ours emptied it, or the user's
+    // file carried an empty list) reads better gone.
+    events.retain(|_, groups| groups.as_array().is_some_and(|g| !g.is_empty()));
+}
+
+fn ensure_object<'a>(
+    root: &'a mut serde_json::Value,
+    key: &str,
+) -> &'a mut serde_json::Map<String, serde_json::Value> {
+    if !root.get(key).map(|v| v.is_object()).unwrap_or(false) {
+        root[key] = serde_json::json!({});
+    }
+    root.get_mut(key).unwrap().as_object_mut().unwrap()
+}
+
+fn ensure_array<'a>(
+    parent: &'a mut serde_json::Map<String, serde_json::Value>,
+    key: &str,
+) -> &'a mut Vec<serde_json::Value> {
+    let v = parent
+        .entry(key.to_string())
+        .or_insert_with(|| serde_json::json!([]));
+    if !v.is_array() {
+        *v = serde_json::json!([]);
+    }
+    v.as_array_mut().unwrap()
+}
+
+fn write_atomic(path: &Path, value: &serde_json::Value) -> Result<(), HooksError> {
+    if let Some(dir) = path.parent() {
+        std::fs::create_dir_all(dir)?;
+    }
+    let tmp = path.with_extension("json.maestro-tmp");
+    std::fs::write(&tmp, serde_json::to_string_pretty(value)? + "\n")?;
+    std::fs::rename(&tmp, path)?;
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests;

crates/maestro-hooks/src/tests.rs

@@ -0,0 +1,340 @@
+//! Tests for the shipped hook script (run as a real `/bin/sh` subprocess)
+//! and the settings-file installer. Everything happens under a temp `$HOME`;
+//! the developer's own `~/.claude/settings.json` is never touched.
+
+use std::io::{Read, Write};
+use std::process::{Command, Stdio};
+
+use super::*;
+
+fn sh(script: &str, args: &[&str], envs: &[(&str, &str)], payload: &[u8]) -> std::process::Output {
+    let mut cmd = Command::new("/bin/sh");
+    // `sh -c CMD NAME ARGS…`: NAME fills $0, so the real arguments start at $1.
+    let mut argv = vec!["-c", script, HOOK_MARKER];
+    argv.extend(args.iter().copied());
+    cmd.args(&argv);
+    // A clean env: only what the test passes, plus PATH so curl can spawn.
+    cmd.env_clear();
+    cmd.env("PATH", std::env::var("PATH").unwrap_or_default());
+    for (k, v) in envs {
+        cmd.env(k, v);
+    }
+    let mut child = cmd
+        .stdin(Stdio::piped())
+        .stdout(Stdio::piped())
+        .stderr(Stdio::piped())
+        .spawn()
+        .expect("spawn /bin/sh");
+    // Feed a Claude-Code-style payload on stdin; the script must drain it.
+    child.stdin.take().unwrap().write_all(payload).ok();
+    child.wait_with_output().expect("wait")
+}
+
+const SESSION: &str = "01234567-89ab-cdef-0123-456789abcdef";
+
+/// Accept exactly one HTTP request on a throwaway listener, answer 204, and
+/// hand back the raw request text. Runs `run` with the base URL once the
+/// acceptor thread is in place.
+fn capture_request(run: impl FnOnce(String) -> std::process::Output) -> String {
+    let listener = std::net::TcpListener::bind("127.0.0.1:0").unwrap();
+    let addr = listener.local_addr().unwrap();
+    let handle = std::thread::spawn(move || {
+        let (mut sock, _) = listener.accept().unwrap();
+        let mut buf = [0u8; 4096];
+        let n = sock.read(&mut buf).unwrap();
+        sock.write_all(b"HTTP/1.1 204 No Content\r\nContent-Length: 0\r\n\r\n")
+            .unwrap();
+        String::from_utf8_lossy(&buf[..n]).to_string()
+    });
+    let out = run(format!("http://{addr}"));
+    assert!(out.status.success(), "{:?}", out.stderr);
+    handle.join().unwrap()
+}
+
+fn session_envs(url: &str) -> Vec<(&'static str, String)> {
+    vec![
+        ("MAESTRO_URL", url.to_string()),
+        ("MAESTRO_SESSION_ID", SESSION.to_string()),
+    ]
+}
+
+fn owned_envs<'a>(envs: &'a [(&'static str, String)]) -> Vec<(&'static str, &'a str)> {
+    envs.iter().map(|(k, v)| (*k, v.as_str())).collect()
+}
+
+/// The hook must be invisible outside maestro: no env vars (#103 unset) ⇒
+/// exit 0, no output, stdin drained.
+#[test]
+fn script_exits_silently_without_maestro_env() {
+    for (event, _) in HOOK_EVENTS {
+        let out = sh(HOOK_SCRIPT, &[event], &[], br#"{"session_id":"x"}"#);
+        assert!(out.status.success(), "{event:?}: {:?}", out.stderr);
+        assert!(out.stdout.is_empty(), "{event:?}: {:?}", out.stdout);
+        assert!(out.stderr.is_empty(), "{event:?}: {:?}", out.stderr);
+    }
+}
+
+/// With both env vars set the script POSTs the mapped state to the daemon's
+/// activity endpoint and still exits 0.
+#[test]
+fn script_posts_mapped_state_to_the_activity_endpoint() {
+    // The installer bakes the mapped state into the command's argv; the
+    // script relays whatever it is given.
+    let request = capture_request(|url| {
+        sh(
+            HOOK_SCRIPT,
+            &["Active"],
+            &owned_envs(&session_envs(&url)),
+            br#"{"session_id":"x"}"#,
+        )
+    });
+    assert!(request.starts_with("POST "), "{request}");
+    assert!(
+        request.contains(&format!("/api/sessions/{SESSION}/activity")),
+        "{request}"
+    );
+    assert!(request.contains(r#""state":"Active""#), "{request}");
+}
+
+/// Every event maps to the state the contract specifies.
+#[test]
+fn event_state_mapping_matches_the_contract() {
+    let map: std::collections::HashMap<&str, &str> = HOOK_EVENTS.into_iter().collect();
+    assert_eq!(map["PreToolUse"], "Active");
+    assert_eq!(map["PostToolUse"], "Active");
+    assert_eq!(map["Notification"], "AwaitingInput");
+    assert_eq!(map["Stop"], "AwaitingInput");
+    assert_eq!(map["StopFailure"], "Error");
+}
+
+/// A `StopFailure` payload names the API error that ended the turn; the
+/// script reports its `error` spelling as the report's `detail` so a card
+/// can show why (#114).
+#[test]
+fn script_reports_the_error_spelling_as_detail() {
+    let request = capture_request(|url| {
+        sh(
+            HOOK_SCRIPT,
+            &["Error"],
+            &owned_envs(&session_envs(&url)),
+            br#"{"session_id":"abc","hook_event_name":"StopFailure","error":"rate_limit","error_details":"429 Too Many Requests"}"#,
+        )
+    });
+    assert!(request.contains(r#""state":"Error""#), "{request}");
+    assert!(request.contains(r#""detail":"rate_limit""#), "{request}");
+}
+
+/// An `error` value that is not a plain enum spelling (or a payload without
+/// one at all) must never produce a broken body — no detail is posted.
+#[test]
+fn script_posts_no_detail_for_an_unexpected_error_value() {
+    let request = capture_request(|url| {
+        sh(
+            HOOK_SCRIPT,
+            &["Error"],
+            &owned_envs(&session_envs(&url)),
+            br#"{"hook_event_name":"StopFailure","error":"429 \"Too Many\" \\ requests"}"#,
+        )
+    });
+    assert!(request.contains(r#""state":"Error""#), "{request}");
+    assert!(!request.contains("detail"), "{request}");
+}
+
+/// Events whose payload carries no error fields post a bare body — never an
+/// empty or stale detail.
+#[test]
+fn script_posts_no_detail_for_events_without_an_error() {
+    let request = capture_request(|url| {
+        sh(
+            HOOK_SCRIPT,
+            &["AwaitingInput"],
+            &owned_envs(&session_envs(&url)),
+            br#"{"hook_event_name":"Stop","stop_hook_active":false}"#,
+        )
+    });
+    assert!(request.contains(r#""state":"AwaitingInput""#), "{request}");
+    assert!(!request.contains("detail"), "{request}");
+}
+
+/// A dead or unreachable daemon must never fail — or slow down — a session.
+#[test]
+fn script_ignores_daemon_failure() {
+    // Port 1 on localhost is closed in practice; curl fails fast.
+    let out = sh(
+        HOOK_SCRIPT,
+        &["Stop"],
+        &[
+            ("MAESTRO_URL", "http://127.0.0.1:1"),
+            ("MAESTRO_SESSION_ID", "00000000-0000-0000-0000-000000000000"),
+        ],
+        br#"{"session_id":"x"}"#,
+    );
+    assert!(out.status.success());
+}
+
+// --- installer -------------------------------------------------------------
+
+fn installed_commands(settings: &Path) -> Vec<String> {
+    serde_json::from_str::<serde_json::Value>(&std::fs::read_to_string(settings).unwrap())
+        .unwrap()
+        .get("hooks")
+        .and_then(|h| h.as_object())
+        .into_iter()
+        .flat_map(|events| events.values())
+        .filter_map(|g| g.as_array())
+        .flatten()
+        .filter_map(|g| g.get("hooks"))
+        .filter_map(|h| h.as_array())
+        .flatten()
+        .filter_map(|h| h.get("command"))
+        .filter_map(|c| c.as_str())
+        .map(str::to_string)
+        .collect()
+}
+
+/// Fresh install registers exactly one command per event, all pointing at the
+/// script with the right state argument.
+#[test]
+fn fresh_install_registers_every_event() {
+    let dir = tempfile::tempdir().unwrap();
+    let home = dir.path();
+    write_script(&script_path(home)).unwrap();
+    install(&settings_path(home), &script_path(home)).unwrap();
+
+    let cmds = installed_commands(&settings_path(home));
+    assert_eq!(cmds.len(), HOOK_EVENTS.len());
+    let joined = cmds.join("\n");
+    assert_eq!(joined.matches("Active").count(), 2);
+    assert!(joined.contains("Error"));
+    assert_eq!(joined.matches("AwaitingInput").count(), 2);
+    for cmd in &cmds {
+        assert!(cmd.contains(SCRIPT_FILE_NAME));
+    }
+}
+
+/// Running install twice changes nothing further — no duplicates.
+#[test]
+fn install_is_idempotent() {
+    let dir = tempfile::tempdir().unwrap();
+    let home = dir.path();
+    install(&settings_path(home), &script_path(home)).unwrap();
+    let once = std::fs::read_to_string(settings_path(home)).unwrap();
+
+    install(&settings_path(home), &script_path(home)).unwrap();
+    let twice = std::fs::read_to_string(settings_path(home)).unwrap();
+    assert_eq!(once, twice);
+    assert_eq!(
+        installed_commands(&settings_path(home)).len(),
+        HOOK_EVENTS.len()
+    );
+}
+
+/// An older maestro entry under the same events is updated in place, not
+/// duplicated next to the new one.
+#[test]
+fn install_updates_an_older_maestro_hook_in_place() {
+    let dir = tempfile::tempdir().unwrap();
+    let settings = dir.path().join(".claude/settings.json");
+    std::fs::create_dir_all(settings.parent().unwrap()).unwrap();
+    let old_script = "/old/location/maestro-claude-hook.sh Active";
+    std::fs::write(
+        &settings,
+        serde_json::json!({
+            "model": "sonnet",
+            "hooks": {
+                "Stop": [{"hooks": [{"type": "command", "command": old_script}]}],
+            },
+        })
+        .to_string(),
+    )
+    .unwrap();
+
+    let new_script = dir
+        .path()
+        .join(".local/share/maestro")
+        .join(SCRIPT_FILE_NAME);
+    install(&settings, &new_script).unwrap();
+
+    let cmds = installed_commands(&settings);
+    assert_eq!(
+        cmds.len(),
+        HOOK_EVENTS.len(),
+        "old entry replaced, not kept: {cmds:?}"
+    );
+    assert!(!cmds.iter().any(|c| c == old_script));
+    let root: serde_json::Value =
+        serde_json::from_str(&std::fs::read_to_string(&settings).unwrap()).unwrap();
+    assert_eq!(root["model"], "sonnet", "unrelated fields survive");
+}
+
+/// A stale maestro entry under an event we no longer use is cleaned up too;
+/// the user's own hooks are never touched.
+#[test]
+fn install_preserves_foreign_hooks_and_removes_stale_maestro_ones() {
+    let dir = tempfile::tempdir().unwrap();
+    let settings = dir.path().join(".claude/settings.json");
+    std::fs::create_dir_all(settings.parent().unwrap()).unwrap();
+    std::fs::write(
+        &settings,
+        serde_json::json!({
+            "hooks": {
+                "PreToolUse": [{"matcher": "Bash", "hooks": [
+                    {"type": "command", "command": "my-own-linter.sh"},
+                ]}],
+                "UserPromptSubmit": [{"hooks": [
+                    {"type": "command", "command": "/old/maestro-claude-hook.sh Active"},
+                ]}],
+            },
+        })
+        .to_string(),
+    )
+    .unwrap();
+
+    let new_script = dir
+        .path()
+        .join(".local/share/maestro")
+        .join(SCRIPT_FILE_NAME);
+    install(&settings, &new_script).unwrap();
+
+    let root: serde_json::Value =
+        serde_json::from_str(&std::fs::read_to_string(&settings).unwrap()).unwrap();
+    // Foreign hook untouched.
+    let pre = root["hooks"]["PreToolUse"].as_array().unwrap();
+    assert_eq!(pre[0]["hooks"][0]["command"], "my-own-linter.sh");
+    // Stale maestro event gone.
+    assert!(root["hooks"].get("UserPromptSubmit").is_none());
+    // Our events present, nothing else maestro-related anywhere.
+    let cmds = installed_commands(&settings);
+    assert_eq!(
+        cmds.iter().filter(|c| c.contains(HOOK_MARKER)).count(),
+        HOOK_EVENTS.len(),
+        "{cmds:?}"
+    );
+}
+
+/// `is_installed` flips only once a maestro entry exists.
+#[test]
+fn is_installed_tracks_reality() {
+    let dir = tempfile::tempdir().unwrap();
+    let home = dir.path();
+    assert!(!is_installed(&settings_path(home)));
+    install_for_home(home).unwrap();
+    assert!(is_installed(&settings_path(home)));
+}
+
+/// The full home-level install leaves the script executable.
+#[test]
+fn install_for_home_writes_an_executable_script() {
+    let dir = tempfile::tempdir().unwrap();
+    let home = dir.path();
+    install_for_home(home).unwrap();
+    #[cfg(unix)]
+    {
+        use std::os::unix::fs::PermissionsExt;
+        let mode = std::fs::metadata(script_path(home))
+            .unwrap()
+            .permissions()
+            .mode();
+        assert_eq!(mode & 0o111, 0o111);
+    }
+}

crates/maestro-protocol/src/client.rs

@@ -16,7 +16,7 @@ use uuid::Uuid;
 use crate::routes::{self, UrlError};
 use crate::{
     ApiError, BranchInfo, CreateSessionRequest, DaemonInfo, DirListing, ErrorInfo, GitRoot,
-    KillOutcome, Project, RecentDirs, RetainedWorktree, Session,
+    KillOutcome, Project, RecentDirs, ReportActivityRequest, RetainedWorktree, Session,
 };
 
 /// Time budget for establishing a TCP connection to the daemon.
@@ -134,6 +134,21 @@ impl DaemonClient {
         json(resp).await
     }
 
+    /// `POST /api/sessions/:id/activity` (#105): report an agent-observed
+    /// state. The daemon holds it above its own inference for a TTL, then
+    /// resumes inference. Answers `204 No Content`.
+    pub async fn report_activity(
+        &self,
+        id: Uuid,
+        req: &ReportActivityRequest,
+    ) -> Result<(), ClientError> {
+        let resp = self
+            .send(Method::POST, &routes::session_activity(id), &[], Some(req))
+            .await?;
+        check(resp).await?;
+        Ok(())
+    }
+
     pub async fn daemon_info(&self) -> Result<DaemonInfo, ClientError> {
         self.get(routes::INFO, &[]).await
     }

crates/maestro-protocol/src/display.rs

@@ -0,0 +1,321 @@
+//! Path-abbreviation helpers shared by every client that renders a session's
+//! directory (CLI, TUI, web (#117)). Ports of `web/src/types.ts` and
+//! `web/src/tree.ts`'s `abbreviateCwd`, `abbreviateFolderName`, `mergeLinear`,
+//! and `sessionTreePath` — keep them in sync.
+
+use std::path::{Path, PathBuf};
+
+use crate::Session;
+
+/// Collapse a daemon's home dir to `~`. `home` empty leaves the path
+/// untouched. Mirrors the web's `abbreviateCwd`.
+pub fn abbreviate_dir(path: &Path, home: &str) -> String {
+    let p = path.to_string_lossy();
+    if !home.is_empty() {
+        if p == home {
+            return "~".into();
+        }
+        if let Some(rest) = p.strip_prefix(&format!("{home}/")) {
+            return format!("~/{rest}");
+        }
+    }
+    p.into_owned()
+}
+
+/// Result of [`abbreviate_folder_name`]: the last path segment kept verbatim,
+/// and — when there was something to collapse — the shortened lead-in a
+/// caller can render dimmed (the web's `.folder-stem`).
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct AbbreviatedFolderName {
+    /// The collapsed earlier segments, joined by `/`, with no trailing
+    /// slash. `None` when `name` had two or fewer segments — nothing to
+    /// gain from collapsing, so `last` carries the name unabbreviated.
+    pub stem: Option<String>,
+    pub last: String,
+}
+
+/// `~/git.naps.pt/naps62/maestro` → stem `~/g/n`, last `maestro`: keep the
+/// last segment verbatim, collapse every earlier one to its first character.
+/// Two-or-fewer segments are left alone. Mirrors the web's
+/// `abbreviateFolderName`, minus the HTML escaping/wrapping — a ratatui
+/// caller styles `stem` dim itself rather than parsing markup out of it.
+pub fn abbreviate_folder_name(name: &str) -> AbbreviatedFolderName {
+    let parts: Vec<&str> = name.split('/').collect();
+    if parts.len() <= 2 {
+        return AbbreviatedFolderName {
+            stem: None,
+            last: name.to_string(),
+        };
+    }
+    let last = parts[parts.len() - 1].to_string();
+    let stem = parts[..parts.len() - 1]
+        .iter()
+        .map(|p| {
+            if *p == "~" {
+                "~".to_string()
+            } else {
+                p.chars().next().map(String::from).unwrap_or_default()
+            }
+        })
+        .collect::<Vec<_>>()
+        .join("/");
+    AbbreviatedFolderName {
+        stem: Some(stem),
+        last,
+    }
+}
+
+/// The directory a session lives in: its live `current_cwd` if the daemon
+/// has observed one, else the spawn `cwd`. Mirrors the web's `sessionCwd`.
+fn session_cwd(s: &Session) -> Option<PathBuf> {
+    if let Some(cur) = &s.current_cwd {
+        if !cur.as_os_str().is_empty() {
+            return Some(cur.clone());
+        }
+    }
+    if !s.cwd.as_os_str().is_empty() {
+        return Some(s.cwd.clone());
+    }
+    None
+}
+
+/// Where a session sits in the directory tree. A worktree session belongs to
+/// its repository, not to the worktree (#99): otherwise `~/tea/agent-skills`
+/// grows a `~/tea/agent-skills/worktrees/largo-clarinet` folder holding one
+/// session of the same name, and the repository stops being where you look
+/// for the work. Mirrors the web's `sessionTreePath`.
+pub fn session_tree_path(s: &Session) -> Option<PathBuf> {
+    if let Some(wt) = &s.worktree {
+        return Some(wt.base_repo.clone());
+    }
+    session_cwd(s)
+}
+
+/// One node of a directory tree grouping sessions by path, generic over the
+/// leaf payload since building the tree itself (grouping key, sort order,
+/// filtering) is not this crate's job — only [`merge_linear`] is.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum TreeNode<T> {
+    Folder(TreeFolder<T>),
+    Leaf(T),
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct TreeFolder<T> {
+    pub name: String,
+    pub path: String,
+    pub children: Vec<TreeNode<T>>,
+}
+
+/// Fold a folder with a single folder-child into one node (`a` + `b` →
+/// `a/b`), repeating down the chain, then recurse into the surviving
+/// branches. The merged node keeps the deepest path so collapse/expand state
+/// stays stable as it grows. Mirrors the web's `mergeLinear`.
+pub fn merge_linear<T>(folder: TreeFolder<T>) -> TreeFolder<T> {
+    let mut cur = folder;
+    loop {
+        let single_folder_child =
+            cur.children.len() == 1 && matches!(cur.children[0], TreeNode::Folder(_));
+        if !single_folder_child {
+            break;
+        }
+        let child = match cur.children.pop().expect("checked len == 1 above") {
+            TreeNode::Folder(f) => f,
+            TreeNode::Leaf(_) => unreachable!("checked matches! above"),
+        };
+        cur = TreeFolder {
+            name: format!("{}/{}", cur.name, child.name),
+            path: child.path,
+            children: child.children,
+        };
+    }
+    cur.children = cur
+        .children
+        .into_iter()
+        .map(|c| match c {
+            TreeNode::Folder(f) => TreeNode::Folder(merge_linear(f)),
+            leaf => leaf,
+        })
+        .collect();
+    cur
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::{SessionStatus, SessionWorktree};
+    use chrono::{TimeZone, Utc};
+    use std::collections::HashMap;
+    use uuid::Uuid;
+
+    fn session(cwd: &str) -> Session {
+        Session {
+            id: Uuid::from_u128(1),
+            cwd: PathBuf::from(cwd),
+            command: "bash".into(),
+            env: HashMap::new(),
+            metadata: HashMap::new(),
+            worktree: None,
+            status: SessionStatus::Running,
+            created_at: Utc.with_ymd_and_hms(2026, 8, 25, 12, 0, 0).unwrap(),
+            foreground: None,
+            activity: Default::default(),
+            activity_detail: None,
+            last_activity_at: Utc::now(),
+            activity_since: Utc::now(),
+            current_cwd: None,
+            blocked_work: None,
+        }
+    }
+
+    #[test]
+    fn abbreviate_dir_collapses_home() {
+        assert_eq!(
+            abbreviate_dir(Path::new("/home/naps/maestro"), "/home/naps"),
+            "~/maestro"
+        );
+        assert_eq!(abbreviate_dir(Path::new("/home/naps"), "/home/naps"), "~");
+    }
+
+    #[test]
+    fn abbreviate_dir_leaves_paths_outside_home_untouched() {
+        assert_eq!(
+            abbreviate_dir(Path::new("/srv/work/api"), "/home/naps"),
+            "/srv/work/api"
+        );
+        assert_eq!(
+            abbreviate_dir(Path::new("/srv/work/api"), ""),
+            "/srv/work/api"
+        );
+    }
+
+    #[test]
+    fn abbreviate_folder_name_collapses_the_stem() {
+        let got = abbreviate_folder_name("~/git.naps.pt/naps62/maestro");
+        assert_eq!(
+            got,
+            AbbreviatedFolderName {
+                stem: Some("~/g/n".into()),
+                last: "maestro".into(),
+            }
+        );
+    }
+
+    /// Two-or-fewer segments are left alone — nothing to gain from collapsing.
+    #[test]
+    fn abbreviate_folder_name_two_segment_no_op() {
+        assert_eq!(
+            abbreviate_folder_name("~/work"),
+            AbbreviatedFolderName {
+                stem: None,
+                last: "~/work".into(),
+            }
+        );
+        assert_eq!(
+            abbreviate_folder_name("work"),
+            AbbreviatedFolderName {
+                stem: None,
+                last: "work".into(),
+            }
+        );
+    }
+
+    #[test]
+    fn session_tree_path_prefers_worktree_base_repo() {
+        let mut s = session("/home/n/tea/agent-skills/worktrees/largo-clarinet");
+        s.worktree = Some(SessionWorktree {
+            path: PathBuf::from("/home/n/tea/agent-skills/worktrees/largo-clarinet"),
+            base_repo: PathBuf::from("/home/n/tea/agent-skills"),
+        });
+        assert_eq!(
+            session_tree_path(&s),
+            Some(PathBuf::from("/home/n/tea/agent-skills"))
+        );
+    }
+
+    #[test]
+    fn session_tree_path_falls_back_to_cwd_without_a_worktree() {
+        let s = session("/home/n/tea/arr");
+        assert_eq!(
+            session_tree_path(&s),
+            Some(PathBuf::from("/home/n/tea/arr"))
+        );
+    }
+
+    #[test]
+    fn session_tree_path_prefers_live_current_cwd_over_spawn_cwd() {
+        let mut s = session("/home/n/tea/arr");
+        s.current_cwd = Some(PathBuf::from("/home/n/tea/arr/crates"));
+        assert_eq!(
+            session_tree_path(&s),
+            Some(PathBuf::from("/home/n/tea/arr/crates"))
+        );
+    }
+
+    fn leaf(name: &str) -> TreeNode<String> {
+        TreeNode::Leaf(name.into())
+    }
+
+    fn folder(name: &str, path: &str, children: Vec<TreeNode<String>>) -> TreeFolder<String> {
+        TreeFolder {
+            name: name.into(),
+            path: path.into(),
+            children,
+        }
+    }
+
+    /// The web's mergeLinear test: keeps the deepest path so collapse state
+    /// survives growth.
+    #[test]
+    fn merge_linear_folds_a_chain_and_keeps_the_deepest_path() {
+        let tree = folder("a", "a", vec![TreeNode::Folder(folder("b", "a/b", vec![]))]);
+        let merged = merge_linear(tree);
+        assert_eq!(merged.name, "a/b");
+        assert_eq!(merged.path, "a/b");
+    }
+
+    #[test]
+    fn merge_linear_stops_where_a_directory_branches() {
+        let tree = folder(
+            "git",
+            "git",
+            vec![
+                TreeNode::Folder(folder("one", "git/one", vec![])),
+                TreeNode::Folder(folder("two", "git/two", vec![])),
+            ],
+        );
+        let merged = merge_linear(tree);
+        assert_eq!(merged.name, "git");
+        assert_eq!(merged.children.len(), 2);
+    }
+
+    #[test]
+    fn merge_linear_stops_at_a_leaf() {
+        let tree = folder("a", "a", vec![leaf("session")]);
+        let merged = merge_linear(tree);
+        assert_eq!(merged.name, "a");
+        assert_eq!(merged.children, vec![leaf("session")]);
+    }
+
+    #[test]
+    fn merge_linear_recurses_into_surviving_branches() {
+        let tree = folder(
+            "root",
+            "root",
+            vec![
+                TreeNode::Folder(folder(
+                    "a",
+                    "root/a",
+                    vec![TreeNode::Folder(folder("b", "root/a/b", vec![leaf("s")]))],
+                )),
+                leaf("other"),
+            ],
+        );
+        let merged = merge_linear(tree);
+        assert_eq!(merged.children.len(), 2);
+        let TreeNode::Folder(nested) = &merged.children[0] else {
+            panic!("expected folder")
+        };
+        assert_eq!(nested.name, "a/b");
+    }
+}

crates/maestro-protocol/src/lib.rs

@@ -9,6 +9,7 @@
 
 #[cfg(feature = "client")]
 pub mod client;
+pub mod display;
 pub mod routes;
 
 #[cfg(feature = "client")]
@@ -75,11 +76,24 @@ pub struct Session {
     /// byte stream.
     #[serde(default)]
     pub activity: ActivityState,
+    /// Short human-readable string an agent reported alongside its activity
+    /// (#105) — e.g. why it is in `Error`. Shown on a sidebar card's meta line
+    /// while the report is in force; cleared when the report lapses or is
+    /// replaced. `None` unless an agent reported one.
+    #[serde(default)]
+    pub activity_detail: Option<String>,
     /// Wall-clock time of the session's most recent observed PTY output.
     /// Drives "idle for Ns" displays. Defaults to the Unix epoch on payloads
     /// from daemons that predate the field.
     #[serde(default = "epoch")]
     pub last_activity_at: DateTime<Utc>,
+    /// Wall-clock time at which the session entered its current
+    /// [`ActivityState`] (#102) — how long it has been `Active`, `Idle` or
+    /// `AwaitingInput`. Distinct from [`Self::last_activity_at`], which only
+    /// tracks the last observed PTY output. Populated by #104; defaults to the
+    /// Unix epoch on payloads from daemons that predate the field.
+    #[serde(default = "epoch")]
+    pub activity_since: DateTime<Utc>,
     /// The pane's *current* working directory (`#{pane_current_path}`) — distinct
     /// from [`Session::cwd`], the directory it was spawned in. The activity
     /// watcher refreshes it as the user `cd`s around; it drives the web UI's
@@ -110,7 +124,12 @@ pub enum SessionStatus {
 /// Inferred session activity, orthogonal to [`SessionStatus`] (NAP-340). The
 /// daemon derives this from tmux pane state, PTY quiescence, and `/proc`
 /// inspection — never by parsing the terminal byte stream.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize, Default)]
+///
+/// Deserializes leniently (#110, SIDEBAR.md Precedence): an unknown variant
+/// from a newer daemon becomes [`ActivityState::Idle`] instead of failing the
+/// whole `Session`. Non-string values still error — only variant names are
+/// forgiven.
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Default)]
 pub enum ActivityState {
     /// Producing output, or the foreground process is busy.
     Active,
@@ -119,6 +138,64 @@ pub enum ActivityState {
     Idle,
     /// Blocked on a `read()` from the pty — waiting on the user.
     AwaitingInput,
+    /// The agent running in the session reported a failure (#102). Never
+    /// inferred by the daemon; only set when an agent reports it (#105).
+    Error,
+}
+
+impl<'de> Deserialize<'de> for ActivityState {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        let s = String::deserialize(deserializer)?;
+        Ok(match s.as_str() {
+            "Active" => Self::Active,
+            "AwaitingInput" => Self::AwaitingInput,
+            "Error" => Self::Error,
+            // Known or not, any other spelling degrades to the neutral default
+            _ => Self::Idle,
+        })
+    }
+}
+
+/// HTTP `POST /api/sessions/:id/activity` body (#105): an agent's report of
+/// its own state. The daemon holds the reported state above its own inference
+/// for a fixed TTL, then resumes inference.
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+pub struct ReportActivityRequest {
+    /// Parsed strictly, unlike [`ActivityState`]'s own lenient `Deserialize`
+    /// (#110). Leniency exists so a client reading a *newer* daemon's snapshot
+    /// degrades an unrecognised state to `Idle` instead of dropping the whole
+    /// session. A report travelling the other way has no such excuse: an agent
+    /// posting a state this daemon does not know is a bug in the agent, and
+    /// silently recording it as `Idle` would hide that behind a 204.
+    #[serde(deserialize_with = "strict_activity_state")]
+    pub state: ActivityState,
+    /// Short human string shown next to the state (e.g. an error message).
+    /// The daemon caps its length server-side.
+    #[serde(default)]
+    pub detail: Option<String>,
+}
+
+/// Reject an unknown [`ActivityState`] spelling instead of degrading it to
+/// `Idle`. Used only by [`ReportActivityRequest`]; see the note there.
+fn strict_activity_state<'de, D>(deserializer: D) -> Result<ActivityState, D::Error>
+where
+    D: serde::Deserializer<'de>,
+{
+    use serde::de::Error as _;
+    let s = String::deserialize(deserializer)?;
+    match s.as_str() {
+        "Active" => Ok(ActivityState::Active),
+        "Idle" => Ok(ActivityState::Idle),
+        "AwaitingInput" => Ok(ActivityState::AwaitingInput),
+        "Error" => Ok(ActivityState::Error),
+        other => Err(D::Error::unknown_variant(
+            other,
+            &["Active", "Idle", "AwaitingInput", "Error"],
+        )),
+    }
 }
 
 /// Optional worktree request attached to a `CreateSessionRequest`.
@@ -534,9 +611,13 @@ mod tests {
                 .with_timezone(&Utc),
             foreground: Some("claude".into()),
             activity: ActivityState::Active,
+            activity_detail: None,
             last_activity_at: DateTime::parse_from_rfc3339("2026-05-24T12:05:00Z")
                 .unwrap()
                 .with_timezone(&Utc),
+            activity_since: DateTime::parse_from_rfc3339("2026-05-24T12:04:30Z")
+                .unwrap()
+                .with_timezone(&Utc),
             current_cwd: Some(PathBuf::from("/home/naps62/projects/maestro/crates")),
             blocked_work: None,
         }
@@ -588,6 +669,35 @@ mod tests {
         );
     }
 
+    #[test]
+    fn activity_since_defaults_to_epoch_on_legacy_payload() {
+        // A daemon predating #102 omits `activity_since`; it must deserialize
+        // to the forward-compat default 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.activity_since, epoch());
+
+        let full = sample_session();
+        assert_eq!(full, round_trip(&full));
+    }
+
+    // #102: nothing infers `Error`; only #105's agent-reported failure sets it.
+    #[test]
+    fn error_activity_state_serializes_pascal_case_and_idle_stays_default() {
+        assert_eq!(
+            serde_json::to_value(ActivityState::Error).unwrap(),
+            serde_json::json!("Error")
+        );
+        assert_eq!(ActivityState::default(), ActivityState::Idle);
+    }
+
     #[test]
     fn activity_state_serializes_pascal_case_and_defaults_idle() {
         assert_eq!(
@@ -597,6 +707,78 @@ mod tests {
         assert_eq!(ActivityState::default(), ActivityState::Idle);
     }
 
+    // #110 / SIDEBAR.md Precedence: a future daemon may send an
+    // `ActivityState` variant this client does not know; it must degrade to
+    // the neutral default instead of failing the whole `Session`.
+    #[test]
+    fn unknown_activity_state_variant_deserializes_to_idle() {
+        assert_eq!(
+            serde_json::from_value::<ActivityState>(serde_json::json!("Teleported")).unwrap(),
+            ActivityState::Idle
+        );
+
+        let mut future = serde_json::to_value(sample_session()).unwrap();
+        future["activity"] = serde_json::json!("QuantumEntangled");
+        let s: Session = serde_json::from_value(future).unwrap();
+        assert_eq!(s.activity, ActivityState::Idle);
+    }
+
+    #[test]
+    fn non_string_activity_payload_still_fails_deserialization() {
+        let json = serde_json::json!({
+            "id": Uuid::from_u128(1),
+            "cwd": "/tmp",
+            "command": "bash",
+            "status": "Running",
+            "created_at": "2026-05-24T12:00:00Z",
+            "activity": 42,
+        });
+        assert!(serde_json::from_value::<Session>(json).is_err());
+    }
+
+    #[test]
+    fn activity_detail_defaults_to_none_on_legacy_payload() {
+        // #105: a daemon predating the detail field omits it; 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.activity_detail, None);
+
+        let mut reported = sample_session();
+        reported.activity = ActivityState::Error;
+        reported.activity_detail = Some("build failed".into());
+        assert_eq!(reported.clone(), round_trip(&reported));
+    }
+
+    #[test]
+    fn report_activity_request_defaults_detail_and_rejects_unknown_state() {
+        let bare: ReportActivityRequest =
+            serde_json::from_value(serde_json::json!({ "state": "Error" })).unwrap();
+        assert_eq!(bare.state, ActivityState::Error);
+        assert_eq!(bare.detail, None);
+
+        let full = ReportActivityRequest {
+            state: ActivityState::AwaitingInput,
+            detail: Some("waiting on permission".into()),
+        };
+        assert_eq!(full, round_trip(&full));
+
+        // Unknown state values are rejected rather than coerced (#105).
+        assert!(
+            serde_json::from_value::<ReportActivityRequest>(serde_json::json!({
+                "state": "Teleported"
+            }))
+            .is_err()
+        );
+    }
+
     #[test]
     fn session_round_trips() {
         let s = sample_session();

crates/maestro-protocol/src/routes.rs

@@ -47,6 +47,11 @@ pub fn session(id: Uuid) -> String {
     format!("{SESSIONS}/{id}")
 }
 
+/// `POST /api/sessions/:id/activity` (#105): an agent reports its own state.
+pub fn session_activity(id: Uuid) -> String {
+    format!("{SESSIONS}/{id}/activity")
+}
+
 /// `DELETE /api/worktrees/:id` — reclaim one retained worktree (#80).
 pub fn worktree(id: Uuid) -> String {
     format!("{WORKTREES}/{id}")
@@ -61,6 +66,7 @@ pub fn attach(id: Uuid) -> String {
 /// registers the same paths [`session`] and [`attach`] build.
 pub mod patterns {
     pub const SESSION: &str = "/api/sessions/:id";
+    pub const SESSION_ACTIVITY: &str = "/api/sessions/:id/activity";
     pub const ATTACH: &str = "/api/attach/:id";
     pub const WORKTREE: &str = "/api/worktrees/:id";
 }
@@ -169,6 +175,10 @@ mod tests {
             session(id()),
             "/api/sessions/6f1a7c0e-0f5e-4a2b-9a3d-6b1c2d3e4f50"
         );
+        assert_eq!(
+            session_activity(id()),
+            "/api/sessions/6f1a7c0e-0f5e-4a2b-9a3d-6b1c2d3e4f50/activity"
+        );
         assert_eq!(
             attach(id()),
             "/api/attach/6f1a7c0e-0f5e-4a2b-9a3d-6b1c2d3e4f50"
@@ -191,6 +201,10 @@ mod tests {
             patterns::SESSION.trim_end_matches(":id"),
             session(id()).trim_end_matches(&id().to_string())
         );
+        assert_eq!(
+            patterns::SESSION_ACTIVITY.trim_end_matches(":id/activity"),
+            session(id()).trim_end_matches(&id().to_string())
+        );
         assert_eq!(
             patterns::ATTACH.trim_end_matches(":id"),
             attach(id()).trim_end_matches(&id().to_string())

crates/maestro-testing/src/lib.rs

@@ -41,7 +41,9 @@ pub fn session(id: Uuid, cwd: &str, command: &str) -> Session {
         created_at: Utc::now(),
         foreground: None,
         activity: Default::default(),
+        activity_detail: None,
         last_activity_at: Utc::now(),
+        activity_since: chrono::Utc::now(),
         current_cwd: None,
         blocked_work: None,
     }

crates/maestro-tui/src/action.rs

@@ -31,9 +31,14 @@ pub enum Action {
     FocusSidebar,
     FocusPane(Direction),
 
+    // Session scrollback
+    ScrollPanePageUp,
+    ScrollPanePageDown,
+
     // Sidebar highlight movement
     SidebarNext,
     SidebarPrev,
+    ToggleSidebarGroup,
 
     // Catalog actions on the highlighted sidebar row
     AttachHighlighted,
@@ -46,13 +51,6 @@ pub enum Action {
     /// Open the retained-worktrees view (#85).
     ShowWorktrees,
 
-    // Tabs
-    NewTab,
-    CloseTab,
-    NextTab,
-    PrevTab,
-    GotoTab(u8),
-
     // Chrome
     ToggleSidebar,
     ShowHelp,
@@ -70,8 +68,39 @@ pub enum ActionParseError {
 }
 
 impl Action {
-    /// Parse a canonical action string like `"EnterInsert"`, `"FocusPane(Left)"`,
+    /// Plain-language label for the in-app help menu. Configuration keeps the
-    /// or `"GotoTab(3)"`.
+    /// stable enum spelling; operators should not have to decode it.
+    pub fn help_label(&self) -> String {
+        match self {
+            Action::Noop => "Do nothing".into(),
+            Action::EnterInsert => "Send keys to session".into(),
+            Action::LeaveInsert => "Return to sidebar".into(),
+            Action::FocusSidebar => "Focus sidebar".into(),
+            Action::FocusPane(direction) => {
+                format!(
+                    "Focus session pane ({})",
+                    format!("{direction:?}").to_lowercase()
+                )
+            }
+            Action::ScrollPanePageUp => "Scroll session up one page".into(),
+            Action::ScrollPanePageDown => "Scroll session down one page".into(),
+            Action::SidebarNext => "Select next sidebar item".into(),
+            Action::SidebarPrev => "Select previous sidebar item".into(),
+            Action::ToggleSidebarGroup => "Expand or collapse directory".into(),
+            Action::AttachHighlighted => "Open selected item".into(),
+            Action::ToggleAttachHighlighted => "Open selected item".into(),
+            Action::NewDraftPane => "Create a session".into(),
+            Action::FastForwardSpawn => "Create session with defaults".into(),
+            Action::KillHighlighted => "Kill selected session".into(),
+            Action::ShowWorktrees => "Show retained worktrees".into(),
+            Action::ToggleSidebar => "Show or hide sidebar".into(),
+            Action::ShowHelp => "Show help".into(),
+            Action::Quit => "Quit Maestro".into(),
+        }
+    }
+
+    /// Parse a canonical action string like `"EnterInsert"` or
+    /// `"FocusPane(Left)"`.
     pub fn parse(s: &str) -> Result<Self, ActionParseError> {
         let s = s.trim();
         match s {
@@ -79,18 +108,17 @@ impl Action {
             "EnterInsert" => return Ok(Action::EnterInsert),
             "LeaveInsert" => return Ok(Action::LeaveInsert),
             "FocusSidebar" => return Ok(Action::FocusSidebar),
+            "ScrollPanePageUp" => return Ok(Action::ScrollPanePageUp),
+            "ScrollPanePageDown" => return Ok(Action::ScrollPanePageDown),
             "SidebarNext" => return Ok(Action::SidebarNext),
             "SidebarPrev" => return Ok(Action::SidebarPrev),
+            "ToggleSidebarGroup" => return Ok(Action::ToggleSidebarGroup),
             "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),
-            "PrevTab" => return Ok(Action::PrevTab),
             "ToggleSidebar" => return Ok(Action::ToggleSidebar),
             "ShowHelp" => return Ok(Action::ShowHelp),
             "Quit" => return Ok(Action::Quit),
@@ -111,13 +139,6 @@ impl Action {
                 })?;
                 Ok(Action::FocusPane(dir))
             }
-            "GotoTab" => {
-                let n: u8 = arg.parse().map_err(|_| ActionParseError::BadArg {
-                    action: name.to_string(),
-                    detail: format!("expected u8 0..=255, got {arg:?}"),
-                })?;
-                Ok(Action::GotoTab(n))
-            }
             _ => Err(ActionParseError::Unknown(name.to_string())),
         }
     }
@@ -137,7 +158,6 @@ impl fmt::Display for Action {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {
             Action::FocusPane(d) => write!(f, "FocusPane({d:?})"),
-            Action::GotoTab(n) => write!(f, "GotoTab({n})"),
             other => write!(f, "{other:?}"),
         }
     }
@@ -154,6 +174,13 @@ mod tests {
         assert_eq!(Action::parse("  Noop  ").unwrap(), Action::Noop);
     }
 
+    #[test]
+    fn help_labels_are_plain_language() {
+        assert_eq!(Action::EnterInsert.help_label(), "Send keys to session");
+        assert_eq!(Action::AttachHighlighted.help_label(), "Open selected item");
+        assert!(!Action::NewDraftPane.help_label().contains("NewDraftPane"));
+    }
+
     #[test]
     fn parses_focus_pane_directions() {
         assert_eq!(
@@ -166,12 +193,6 @@ mod tests {
         );
     }
 
-    #[test]
-    fn parses_goto_tab() {
-        assert_eq!(Action::parse("GotoTab(3)").unwrap(), Action::GotoTab(3));
-        assert_eq!(Action::parse("GotoTab(0)").unwrap(), Action::GotoTab(0));
-    }
-
     #[test]
     fn rejects_unknown_action() {
         let err = Action::parse("Frobnicate").unwrap_err();
@@ -186,22 +207,10 @@ mod tests {
         );
     }
 
-    #[test]
-    fn rejects_non_numeric_tab_arg() {
-        let err = Action::parse("GotoTab(abc)").unwrap_err();
-        assert!(matches!(err, ActionParseError::BadArg { ref action, .. } if action == "GotoTab"));
-    }
-
-    #[test]
-    fn rejects_overflow_tab_arg() {
-        let err = Action::parse("GotoTab(9999)").unwrap_err();
-        assert!(matches!(err, ActionParseError::BadArg { .. }));
-    }
-
     #[test]
     fn rejects_unclosed_paren() {
-        let err = Action::parse("GotoTab(3").unwrap_err();
+        let err = Action::parse("FocusPane(Left").unwrap_err();
-        assert_eq!(err, ActionParseError::Malformed("GotoTab(3".into()));
+        assert_eq!(err, ActionParseError::Malformed("FocusPane(Left".into()));
     }
 
     /// The fast-forward pair sits next to the draft-pane key (#67).
@@ -220,8 +229,8 @@ mod tests {
             Action::EnterInsert,
             Action::Quit,
             Action::NewDraftPane,
+            Action::ScrollPanePageDown,
             Action::FocusPane(Direction::Right),
-            Action::GotoTab(7),
         ] {
             let s = a.to_string();
             assert_eq!(Action::parse(&s).unwrap(), a, "round-trip for {a:?}");

crates/maestro-tui/src/app.rs

@@ -30,15 +30,16 @@ use crate::catalog::CatalogStore;
 use crate::config::TuiConfig;
 use crate::draft::DraftInputResult;
 use crate::emulators::SessionEmulators;
-use crate::input::{canonicalise, ChordResult, ChordState, ClickTracker, InputKey};
+use crate::input::{
+    canonicalise, ChordResult, ChordState, ClickTracker, InputKey, MouseKind, Region,
+};
 use crate::keymap::Mode;
 use crate::overlays::HelpOverlay;
 use crate::pane::{Pane, PaneStatus};
 use crate::render::{draw, RegionMap, RenderInputs};
 use crate::session_task::{SessionInput, SessionTask};
 use crate::sidebar::Sidebar;
-use crate::state::{AppState, Focus, OverlayKind, PaneRef};
+use crate::state::{AppState, Focus, OverlayKind, PaneRef, SidebarItem};
-use crate::tabs::TabBar;
 use crate::worktrees::WorktreesView;
 use crate::TuiError;
 
@@ -52,6 +53,7 @@ enum OverlayDecision {
 
 pub struct App {
     cfg: TuiConfig,
+    home_dir: String,
     catalog: CatalogStore,
     emulators: SessionEmulators,
     state: AppState,
@@ -137,6 +139,7 @@ impl App {
             .expect("build reqwest client");
         Self {
             cfg,
+            home_dir: std::env::var("HOME").unwrap_or_default(),
             catalog,
             emulators: SessionEmulators::default(),
             state: AppState::new(),
@@ -158,6 +161,9 @@ impl App {
         mut self,
         terminal: &mut Terminal<CrosstermBackend<Stdout>>,
     ) -> Result<(), TuiError> {
+        if let Ok(info) = self.daemon.daemon_info().await {
+            self.home_dir = info.home_dir;
+        }
         let mut events = EventStream::new();
         loop {
             self.redraw(terminal)?;
@@ -197,6 +203,15 @@ impl App {
             return Ok(false);
         }
 
+        if self.handle_sidebar_mouse(&key) {
+            return Ok(false);
+        }
+
+        if let Some(effect) = self.handle_pane_scroll(&key) {
+            self.perform(effect.into_iter().collect()).await;
+            return Ok(false);
+        }
+
         let known = self.cfg.keymap.known_bindings(self.state.mode);
         match self.chord.feed(&key, &known) {
             ChordResult::Pending => Ok(false),
@@ -224,6 +239,34 @@ impl App {
         }
     }
 
+    /// Clicks select rendered sidebar items directly. Double-clicks continue
+    /// through the keymap so the configured attach binding remains intact.
+    fn handle_sidebar_mouse(&mut self, key: &InputKey) -> bool {
+        let InputKey::Mouse {
+            kind: MouseKind::Click,
+            region: Region::SidebarRow,
+            row,
+            ..
+        } = key
+        else {
+            return false;
+        };
+        let Some(item) = self.region.sidebar_item_at(*row) else {
+            return true;
+        };
+        self.state.focus = Focus::Sidebar;
+        match item {
+            SidebarItem::Group(key) => {
+                self.state.sidebar_highlight = Some(SidebarItem::Group(key.clone()));
+                self.toggle_sidebar_group(key);
+            }
+            SidebarItem::Session(id) => {
+                self.state.sidebar_highlight = Some(SidebarItem::Session(id));
+            }
+        }
+        true
+    }
+
     /// Carry out what `dispatch` decided. The only place in `App` that talks to
     /// the daemon.
     async fn perform(&mut self, effects: Vec<Effect>) {
@@ -322,32 +365,37 @@ impl App {
         match act {
             Action::Noop | Action::Quit => {}
             Action::EnterInsert => self.state.mode = Mode::Insert,
-            Action::LeaveInsert => self.state.mode = Mode::Normal,
+            Action::LeaveInsert => {
+                self.state.mode = Mode::Normal;
+                self.state.focus = Focus::Sidebar;
+            }
             Action::FocusSidebar => self.state.focus = Focus::Sidebar,
             Action::FocusPane(_) => {
                 // v1 has one pane per tab; geometric focus motion lands
                 // either in the sidebar or back in the pane.
                 self.state.focus = Focus::Pane;
             }
+            Action::ScrollPanePageUp => self.scroll_active_pane(self.pane_page_rows() as isize),
+            Action::ScrollPanePageDown => {
+                self.scroll_active_pane(-(self.pane_page_rows() as isize))
+            }
             Action::SidebarNext => {
-                let order = visible_sidebar_order(&self.catalog.snapshot());
+                let order = visible_sidebar_order(
+                    &self.catalog.snapshot(),
+                    &self.state.collapsed_sidebar_groups,
+                );
                 self.state.move_sidebar_highlight(&order, 1);
                 self.state.focus = Focus::Sidebar;
             }
             Action::SidebarPrev => {
-                let order = visible_sidebar_order(&self.catalog.snapshot());
+                let order = visible_sidebar_order(
+                    &self.catalog.snapshot(),
+                    &self.state.collapsed_sidebar_groups,
+                );
                 self.state.move_sidebar_highlight(&order, -1);
                 self.state.focus = Focus::Sidebar;
             }
-            Action::NewTab => self.state.new_tab(),
+            Action::ToggleSidebarGroup => self.toggle_highlighted_sidebar_group(),
-            Action::CloseTab => {
-                if let Some(sid) = self.state.close_tab() {
-                    self.release_session(sid);
-                }
-            }
-            Action::NextTab => self.state.next_tab(),
-            Action::PrevTab => self.state.prev_tab(),
-            Action::GotoTab(n) => self.state.goto_tab(n),
             Action::ToggleSidebar => self.state.toggle_sidebar(),
             Action::ShowHelp => {
                 self.help = HelpOverlay {
@@ -356,13 +404,24 @@ impl App {
                 self.state.show_overlay(OverlayKind::Help);
             }
             Action::NewDraftPane => {
+                if let Some(sid) = self.state.active_session() {
+                    self.release_session(sid);
+                }
                 self.state.open_draft_pane();
                 effects.push(Effect::LoadDraft(self.state.active_tab_idx));
             }
             Action::FastForwardSpawn => effects.push(Effect::FastForward),
             Action::AttachHighlighted | Action::ToggleAttachHighlighted => {
-                if let Some(sid) = self.pick_sidebar_target() {
+                if let Some(SidebarItem::Group(key)) = self.state.sidebar_highlight.clone() {
-                    effects.push(Effect::Attach(sid));
+                    self.toggle_sidebar_group(key);
+                } else if let Some(sid) = self.pick_sidebar_target() {
+                    self.state.sidebar_highlight = Some(SidebarItem::Session(sid));
+                    if self.state.active_session() != Some(sid) {
+                        if let Some(previous) = self.state.active_session() {
+                            self.release_session(previous);
+                        }
+                        effects.push(Effect::Attach(sid));
+                    }
                     self.state.attach_to_focused(sid);
                 }
             }
@@ -403,22 +462,127 @@ impl App {
     /// Return the session under the sidebar highlight, falling back to the
     /// first listed session so the user can attach without arrowing first.
     fn pick_sidebar_target(&self) -> Option<Uuid> {
-        if let Some(sid) = self.state.sidebar_highlight {
+        if let Some(SidebarItem::Session(sid)) = self.state.sidebar_highlight {
             return Some(sid);
         }
+        if self.state.sidebar_highlight.is_some() {
+            return None;
+        }
         let snap = self.catalog.snapshot();
         snap.sessions.first().map(|s| s.id)
     }
 
+    fn toggle_highlighted_sidebar_group(&mut self) {
+        let key = match self.state.sidebar_highlight.clone() {
+            Some(SidebarItem::Group(key)) => Some(key),
+            Some(SidebarItem::Session(id)) => self
+                .catalog
+                .snapshot()
+                .sessions
+                .into_iter()
+                .find(|s| s.id == id)
+                .and_then(|s| maestro_protocol::display::session_tree_path(&s)),
+            None => None,
+        };
+        if let Some(key) = key {
+            self.toggle_sidebar_group(key);
+        }
+    }
+
+    fn toggle_sidebar_group(&mut self, key: PathBuf) {
+        let contains_highlight = match self.state.sidebar_highlight {
+            Some(SidebarItem::Session(id)) => {
+                self.catalog
+                    .snapshot()
+                    .sessions
+                    .iter()
+                    .find(|s| s.id == id)
+                    .and_then(maestro_protocol::display::session_tree_path)
+                    .as_ref()
+                    == Some(&key)
+            }
+            _ => false,
+        };
+        self.state.toggle_sidebar_group(key, contains_highlight);
+    }
+
     /// Encode a keystroke for the focused pane. `None` when there is nothing
     /// attached to send it to.
     fn forward_to_session(&mut self, key: &InputKey) -> Option<Effect> {
         let sid = self.state.active_session()?;
-        self.emulators.get(sid)?;
+        let handle = self.emulators.get(sid)?;
         let bytes = encode_key(key)?;
+        handle
+            .screen
+            .lock()
+            .expect("vt100 parser mutex")
+            .set_scrollback(0);
         Some(Effect::Forward { id: sid, bytes })
     }
 
+    fn pane_page_rows(&self) -> usize {
+        self.region
+            .pane
+            .map_or(1, |area| usize::from(area.height.saturating_sub(1).max(1)))
+    }
+
+    /// Positive rows move into older history; negative rows return toward the
+    /// live bottom. vt100 clamps both ends to the retained buffer.
+    fn scroll_active_pane(&mut self, rows: isize) {
+        let Some(sid) = self.state.active_session() else {
+            return;
+        };
+        let Some(handle) = self.emulators.get(sid) else {
+            return;
+        };
+        let mut parser = handle.screen.lock().expect("vt100 parser mutex");
+        let current = parser.screen().scrollback();
+        let next = if rows >= 0 {
+            current.saturating_add(rows as usize)
+        } else {
+            current.saturating_sub(rows.unsigned_abs())
+        };
+        parser.set_scrollback(next);
+    }
+
+    /// Wheel input belongs to the terminal surface in every mode. Normal
+    /// shells move through Maestro's retained history; full-screen programs
+    /// that enabled terminal mouse reporting receive a real wheel event and
+    /// scroll their own alternate-screen content.
+    fn handle_pane_scroll(&mut self, key: &InputKey) -> Option<Option<Effect>> {
+        let InputKey::Mouse {
+            kind,
+            region: Region::Pane,
+            col,
+            row,
+        } = key
+        else {
+            return None;
+        };
+        let lines = match kind {
+            MouseKind::ScrollUp => 3,
+            MouseKind::ScrollDown => -3,
+            _ => return None,
+        };
+        let sid = self.state.active_session()?;
+        let handle = self.emulators.get(sid)?;
+        let pane = self.region.pane?;
+        let parser = handle.screen.lock().expect("vt100 parser mutex");
+        if parser.screen().mouse_protocol_mode() != vt100::MouseProtocolMode::None {
+            let bytes = encode_mouse_wheel(
+                *kind,
+                col.saturating_sub(pane.x).saturating_add(1),
+                row.saturating_sub(pane.y).saturating_add(1),
+                parser.screen().mouse_protocol_encoding(),
+            );
+            drop(parser);
+            return Some(Some(Effect::Forward { id: sid, bytes }));
+        }
+        drop(parser);
+        self.scroll_active_pane(lines);
+        Some(None)
+    }
+
     /// Feed one keystroke into the active tab's draft form. Returns the spawn
     /// effect when the user accepted a valid form; an invalid one names the
     /// missing field inside the form (#64) instead of posting.
@@ -704,11 +868,6 @@ impl App {
         let resolved =
             crate::fast_forward::resolve(&discovered, &presets, names.first().cloned(), Utc::now());
         if let Some(req) = resolved.build_request() {
-            // Never eat a pane already showing something: the spawn takes a
-            // fresh tab, same as opening a draft over a session would.
-            if self.state.active_tab().pane.is_some() {
-                self.state.new_tab();
-            }
             self.submit_spawn(req).await;
             return;
         }
@@ -734,6 +893,9 @@ impl App {
                 // Fill the pane in place with the new session (web parity,
                 // #57) and attach to it right away.
                 let sid = session.id;
+                if let Some(previous) = self.state.active_session() {
+                    self.release_session(previous);
+                }
                 self.state.complete_spawn(sid);
                 self.attach(sid);
             }
@@ -811,13 +973,9 @@ impl App {
             .collect();
         let sidebar = Sidebar {
             sessions: snap.sessions.clone(),
-            highlight: self.state.sidebar_highlight,
+            highlight: self.state.sidebar_highlight.clone(),
             attached,
         };
-        let tab_bar = TabBar {
-            tab_names: self.state.tabs.iter().map(|t| t.name.clone()).collect(),
-            active_idx: self.state.active_tab_idx,
-        };
         let active_sid = self.state.active_session();
         let pane = active_sid.and_then(|sid| {
             self.emulators.get(sid).map(|h| Pane {
@@ -830,10 +988,21 @@ impl App {
             Some(PaneRef::Draft(d)) => Some(d),
             _ => None,
         };
+        let pane_title = match self.state.active_tab().pane.as_ref() {
+            Some(PaneRef::Session(sid)) => snap
+                .sessions
+                .iter()
+                .find(|session| session.id == *sid)
+                .map(crate::sidebar::name_for)
+                .unwrap_or_else(|| "session".into()),
+            Some(PaneRef::Draft(_)) => "new session".into(),
+            None => "session".into(),
+        };
 
         let inputs = RenderInputs {
             sidebar: &sidebar,
-            tab_bar: &tab_bar,
+            home_dir: &self.home_dir,
+            pane_title: &pane_title,
             pane: pane.as_ref(),
             state: &self.state,
             draft,
@@ -881,8 +1050,16 @@ impl App {
 /// Order the sidebar walks for `j`/`k`: the sessions in the same order
 /// [`crate::sidebar::Sidebar::render`] emits them. Keeps highlight movement in
 /// visual sync with what the user sees.
-fn visible_sidebar_order(snap: &crate::catalog::CatalogSnapshot) -> Vec<Uuid> {
+fn visible_sidebar_order(
-    snap.sessions.iter().map(|s| s.id).collect()
+    snap: &crate::catalog::CatalogSnapshot,
+    collapsed: &std::collections::HashSet<PathBuf>,
+) -> Vec<SidebarItem> {
+    Sidebar {
+        sessions: snap.sessions.clone(),
+        highlight: None,
+        attached: HashSet::new(),
+    }
+    .rendered_items_with_collapsed(collapsed)
 }
 
 /// Wire encoding for a keystroke headed to a session's PTY. `None` for keys
@@ -916,6 +1093,8 @@ fn encode_key(key: &InputKey) -> Option<Vec<u8>> {
         InputKey::Left => Some(b"\x1b[D".to_vec()),
         InputKey::Home => Some(b"\x1b[H".to_vec()),
         InputKey::End => Some(b"\x1b[F".to_vec()),
+        InputKey::PageUp => Some(b"\x1b[5~".to_vec()),
+        InputKey::PageDown => Some(b"\x1b[6~".to_vec()),
         InputKey::Delete => Some(b"\x1b[3~".to_vec()),
         InputKey::Paste(text) => {
             // Wrap in the DECSET 2004 markers. Raw bytes look like typed keys
@@ -931,6 +1110,39 @@ fn encode_key(key: &InputKey) -> Option<Vec<u8>> {
     }
 }
 
+fn encode_mouse_wheel(
+    kind: MouseKind,
+    col: u16,
+    row: u16,
+    encoding: vt100::MouseProtocolEncoding,
+) -> Vec<u8> {
+    let button = match kind {
+        MouseKind::ScrollUp => 64,
+        MouseKind::ScrollDown => 65,
+        _ => return Vec::new(),
+    };
+    match encoding {
+        vt100::MouseProtocolEncoding::Sgr => format!("\x1b[<{button};{col};{row}M").into_bytes(),
+        vt100::MouseProtocolEncoding::Default => vec![
+            0x1b,
+            b'[',
+            b'M',
+            (button + 32) as u8,
+            col.min(223).saturating_add(32) as u8,
+            row.min(223).saturating_add(32) as u8,
+        ],
+        vt100::MouseProtocolEncoding::Utf8 => {
+            let mut out = b"\x1b[M".to_vec();
+            for value in [button + 32, u32::from(col) + 32, u32::from(row) + 32] {
+                let ch = char::from_u32(value).expect("mouse coordinate is a valid codepoint");
+                let mut bytes = [0; 4];
+                out.extend_from_slice(ch.encode_utf8(&mut bytes).as_bytes());
+            }
+            out
+        }
+    }
+}
+
 /// Build the lines shown by the help overlay from the live keymap, so the
 /// user always sees the bindings that are actually active (defaults + their
 /// own `[tui.keymap.*]` overrides).
@@ -938,14 +1150,14 @@ fn render_help_lines(cfg: &TuiConfig) -> Vec<String> {
     fn section(mode: Mode, label: &str, cfg: &TuiConfig) -> Vec<String> {
         let mut out = vec![format!("{label} mode"), String::new()];
         for (input, action) in cfg.keymap.entries(mode) {
-            out.push(format!("  {input:<24}  {action}"));
+            out.push(format!("  {input:<24}  {}", action.help_label()));
         }
         out.push(String::new());
         out
     }
     let leader = cfg.leader.canonical();
     let mut lines = vec![
-        format!("Leader: {leader}    (Insert → Normal)"),
+        format!("Leader: {leader}    (return to sidebar)"),
         String::new(),
     ];
     lines.extend(section(Mode::Normal, "Normal", cfg));
@@ -1057,19 +1269,11 @@ mod tests {
         let mut app = make_app();
         assert_eq!(app.state.mode, Mode::Normal);
         app.dispatch(Action::EnterInsert);
+        app.state.focus = Focus::Pane;
         assert_eq!(app.state.mode, Mode::Insert);
         app.dispatch(Action::LeaveInsert);
         assert_eq!(app.state.mode, Mode::Normal);
-    }
+        assert_eq!(app.state.focus, Focus::Sidebar);
-
-    #[test]
-    fn new_tab_action_extends_tabs() {
-        let mut app = make_app();
-        app.dispatch(Action::NewTab);
-        app.dispatch(Action::NewTab);
-        assert_eq!(app.state.tabs.len(), 3);
-        app.dispatch(Action::CloseTab);
-        assert_eq!(app.state.tabs.len(), 2);
     }
 
     #[test]
@@ -1079,6 +1283,18 @@ mod tests {
         assert!(matches!(app.state.overlay(), Some(OverlayKind::Help)));
     }
 
+    #[test]
+    fn help_uses_plain_language_instead_of_action_names() {
+        let app = make_app();
+        let help = render_help_lines(&app.cfg).join("\n");
+        assert!(help.contains("Send keys to session"));
+        assert!(help.contains("Create a session"));
+        assert!(help.contains("Expand or collapse directory"));
+        assert!(!help.contains("EnterInsert"));
+        assert!(!help.contains("NewDraftPane"));
+        assert!(!help.contains("ToggleSidebarGroup"));
+    }
+
     #[test]
     fn new_draft_pane_opens_a_focused_draft_in_the_empty_tab() {
         let mut app = make_app();
@@ -1092,21 +1308,19 @@ mod tests {
         assert!(app.state.overlay().is_none(), "no overlay involved");
     }
 
-    /// A tab already showing a session gets a new tab for the draft.
     #[test]
-    fn new_draft_pane_over_a_session_opens_a_new_tab() {
+    fn new_draft_pane_over_a_session_reuses_the_pane() {
         let sid = Uuid::from_u128(10);
         let mut app = app_with_highlighted_session(sid);
         app.dispatch(Action::AttachHighlighted);
 
         app.dispatch(Action::NewDraftPane);
-        assert_eq!(app.state.tabs.len(), 2);
+        assert_eq!(app.state.tabs.len(), 1);
-        assert_eq!(app.state.active_tab_idx, 1);
+        assert_eq!(app.state.active_tab_idx, 0);
         assert!(matches!(
             app.state.active_tab().pane,
             Some(PaneRef::Draft(_))
         ));
-        assert_eq!(app.state.tabs[0].session(), Some(sid));
     }
 
     /// Seed the catalog with one session and highlight it.
@@ -1126,15 +1340,40 @@ mod tests {
                 created_at: Utc::now(),
                 foreground: None,
                 activity: Default::default(),
+                activity_detail: None,
                 last_activity_at: Utc::now(),
+                activity_since: chrono::Utc::now(),
                 current_cwd: None,
                 blocked_work: None,
             }],
         });
         app.dispatch(Action::SidebarNext);
+        app.dispatch(Action::SidebarNext);
         app
     }
 
+    fn test_session(sid: Uuid, cwd: &str) -> maestro_protocol::Session {
+        use chrono::Utc;
+        use maestro_protocol::{Session, SessionStatus};
+        Session {
+            id: sid,
+            command: "bash".into(),
+            cwd: cwd.into(),
+            env: Default::default(),
+            metadata: Default::default(),
+            worktree: None,
+            status: SessionStatus::Running,
+            created_at: Utc::now(),
+            foreground: None,
+            activity: Default::default(),
+            activity_detail: None,
+            last_activity_at: Utc::now(),
+            activity_since: Utc::now(),
+            current_cwd: None,
+            blocked_work: None,
+        }
+    }
+
     #[test]
     fn attach_highlighted_asks_for_an_attach() {
         let sid = Uuid::from_u128(11);
@@ -1144,6 +1383,104 @@ mod tests {
             vec![Effect::Attach(sid)]
         );
         assert_eq!(app.state.active_tab().session(), Some(sid));
+        assert_eq!(app.state.sidebar_highlight, Some(SidebarItem::Session(sid)));
+    }
+
+    #[test]
+    fn enter_on_a_group_toggles_it_without_targeting_a_session() {
+        use maestro_protocol::CatalogEvent;
+
+        let sid = Uuid::from_u128(14);
+        let mut app = make_app();
+        app.catalog.apply_event(CatalogEvent::Snapshot {
+            sessions: vec![test_session(sid, "/repo")],
+        });
+        app.dispatch(Action::SidebarNext);
+        assert_eq!(
+            app.state.sidebar_highlight,
+            Some(SidebarItem::Group(PathBuf::from("/repo")))
+        );
+        assert!(app.dispatch(Action::AttachHighlighted).is_empty());
+        assert!(app
+            .state
+            .collapsed_sidebar_groups
+            .contains(&PathBuf::from("/repo")));
+        assert!(app.dispatch(Action::AttachHighlighted).is_empty());
+        assert!(!app
+            .state
+            .collapsed_sidebar_groups
+            .contains(&PathBuf::from("/repo")));
+        assert!(app.dispatch(Action::KillHighlighted).is_empty());
+        assert!(app.state.overlay().is_none());
+    }
+
+    #[test]
+    fn collapsing_the_group_containing_a_card_highlight_keeps_a_visible_group_highlight() {
+        let sid = Uuid::from_u128(15);
+        let mut app = app_with_highlighted_session(sid);
+        assert_eq!(app.state.sidebar_highlight, Some(SidebarItem::Session(sid)));
+        assert!(app.dispatch(Action::ToggleSidebarGroup).is_empty());
+        assert_eq!(
+            app.state.sidebar_highlight,
+            Some(SidebarItem::Group(PathBuf::from("/")))
+        );
+        assert!(app
+            .state
+            .collapsed_sidebar_groups
+            .contains(&PathBuf::from("/")));
+        assert_eq!(app.state.focus, Focus::Sidebar);
+    }
+
+    #[test]
+    fn clicking_a_group_toggles_it_and_selects_the_group() {
+        let sid = Uuid::from_u128(16);
+        let mut app = app_with_highlighted_session(sid);
+        app.region.sidebar = Some(ratatui::layout::Rect::new(0, 0, 28, 10));
+        app.region.sidebar_items = vec![SidebarItem::Group(PathBuf::from("/"))];
+        let click = InputKey::Mouse {
+            kind: MouseKind::Click,
+            region: Region::SidebarRow,
+            col: 3,
+            row: 1,
+        };
+        assert!(app.handle_sidebar_mouse(&click));
+        assert_eq!(
+            app.state.sidebar_highlight,
+            Some(SidebarItem::Group(PathBuf::from("/")))
+        );
+        assert!(app
+            .state
+            .collapsed_sidebar_groups
+            .contains(&PathBuf::from("/")));
+        assert_eq!(app.state.focus, Focus::Sidebar);
+    }
+
+    #[tokio::test]
+    async fn sidebar_click_dismisses_a_toast_before_handling_the_click() {
+        use crossterm::event::{MouseButton, MouseEvent, MouseEventKind};
+
+        let sid = Uuid::from_u128(17);
+        let mut app = app_with_highlighted_session(sid);
+        app.state.toast("notice");
+        app.region.sidebar = Some(ratatui::layout::Rect::new(0, 0, 28, 10));
+        app.region.sidebar_items = vec![SidebarItem::Group(PathBuf::from("/"))];
+
+        let quit = app
+            .handle_event(CtEvent::Mouse(MouseEvent {
+                kind: MouseEventKind::Down(MouseButton::Left),
+                column: 3,
+                row: 1,
+                modifiers: crossterm::event::KeyModifiers::NONE,
+            }))
+            .await
+            .unwrap();
+
+        assert!(!quit);
+        assert!(app.state.overlay().is_none());
+        assert!(app
+            .state
+            .collapsed_sidebar_groups
+            .contains(&PathBuf::from("/")));
     }
 
     #[test]
@@ -1349,9 +1686,7 @@ mod tests {
         for c in "crimson-otter".chars() {
             app.handle_draft_input(&InputKey::char(c));
         }
-        app.handle_draft_input(&InputKey::Tab); // → worktree toggle
+        app.handle_draft_input(&InputKey::Tab); // → advanced disclosure (collapsed, #93)
-        app.handle_draft_input(&InputKey::Tab); // → branch mode
-        app.handle_draft_input(&InputKey::Tab); // → new-branch name
         app.handle_draft_input(&InputKey::Tab); // → submit
 
         match app.handle_draft_input(&InputKey::Enter).as_slice() {
@@ -1553,8 +1888,8 @@ mod tests {
             panic!("expected a draft pane");
         };
         assert_eq!(draft.command(), "aider");
-        assert_eq!(draft.rows.len(), 1);
+        assert_eq!(draft.groups.len(), 1);
-        assert_eq!(draft.rows[0].project.name, "maestro");
+        assert_eq!(draft.groups[0].main.name, "maestro");
         assert_eq!(draft.home_dir, "/home/u");
         assert_eq!(draft.name.value(), "crimson-otter");
     }
@@ -1602,6 +1937,49 @@ mod tests {
         assert!(app.forward_to_session(&InputKey::Enter).is_none());
     }
 
+    #[test]
+    fn pane_scrollback_moves_and_user_input_returns_to_live_output() {
+        use crate::session_task::{SessionHandle, SessionState};
+        use std::sync::atomic::AtomicU8;
+        use std::sync::{Arc, Mutex};
+        use tokio::sync::mpsc;
+
+        let sid = Uuid::from_u128(91);
+        let mut parser = vt100::Parser::new(2, 20, 20);
+        parser.process(b"one\r\ntwo\r\nthree\r\nfour\r\nfive");
+        let screen = Arc::new(Mutex::new(parser));
+        let handle = SessionHandle {
+            tx: mpsc::channel(1).0,
+            screen: Arc::clone(&screen),
+            state: Arc::new(AtomicU8::new(SessionState::Live as u8)),
+        };
+        let mut app = make_app();
+        app.state.active_tab_mut().pane = Some(PaneRef::Session(sid));
+        app.emulators.insert(sid, handle);
+
+        app.scroll_active_pane(3);
+        assert!(screen.lock().unwrap().screen().scrollback() > 0);
+        assert!(app.forward_to_session(&InputKey::Enter).is_some());
+        assert_eq!(screen.lock().unwrap().screen().scrollback(), 0);
+    }
+
+    #[test]
+    fn mouse_wheel_encoding_supports_sgr_terminals() {
+        assert_eq!(
+            encode_mouse_wheel(MouseKind::ScrollUp, 7, 4, vt100::MouseProtocolEncoding::Sgr,),
+            b"\x1b[<64;7;4M"
+        );
+        assert_eq!(
+            encode_mouse_wheel(
+                MouseKind::ScrollDown,
+                7,
+                4,
+                vt100::MouseProtocolEncoding::Sgr,
+            ),
+            b"\x1b[<65;7;4M"
+        );
+    }
+
     /// Regression review fix: `Paste(_)` used to be silently dropped, so a
     /// paste into an attached session vanished once bracketed paste was
     /// enabled. It also has to keep its DECSET 2004 markers — without them a
@@ -1645,7 +2023,9 @@ mod tests {
                 created_at: Utc::now(),
                 foreground: None,
                 activity: Default::default(),
+                activity_detail: None,
                 last_activity_at: chrono::Utc::now(),
+                activity_since: chrono::Utc::now(),
 
                 current_cwd: None,
                 blocked_work: None,

crates/maestro-tui/src/catalog.rs

@@ -193,7 +193,9 @@ mod tests {
             created_at: Utc::now(),
             foreground: None,
             activity: Default::default(),
+            activity_detail: None,
             last_activity_at: chrono::Utc::now(),
+            activity_since: chrono::Utc::now(),
             current_cwd: None,
             blocked_work: None,
         }

crates/maestro-tui/src/config.rs

@@ -8,13 +8,15 @@
 
 use std::time::Duration;
 
-use maestro_config::TuiSection;
+use maestro_config::{TuiSection, TuiTheme};
 
 use crate::input::InputKey;
 use crate::keymap::{Keymap, KeymapError, Mode};
+use crate::palette::Palette;
 
 #[derive(Debug)]
 pub struct TuiConfig {
+    pub palette: Palette,
     pub leader: InputKey,
     pub chord_timeout: Duration,
     pub keymap: Keymap,
@@ -38,11 +40,12 @@ pub enum TuiConfigError {
 const DEFAULT_NORMAL: &[(&str, &str)] = &[
     // Mode
     ("i", "EnterInsert"),
-    // Sidebar nav
+    // Sidebar navigation
     ("j", "SidebarNext"),
     ("k", "SidebarPrev"),
     ("down", "SidebarNext"),
     ("up", "SidebarPrev"),
+    ("c", "ToggleSidebarGroup"),
     // Catalog actions
     ("enter", "AttachHighlighted"),
     ("s", "NewDraftPane"),
@@ -51,19 +54,17 @@ const DEFAULT_NORMAL: &[(&str, &str)] = &[
     ("S", "FastForwardSpawn"),
     ("x", "KillHighlighted"),
     ("w", "ShowWorktrees"),
-    // Tabs
-    ("ctrl-t", "NewTab"),
-    ("g t", "NextTab"),
-    ("g T", "PrevTab"),
     // Focus
     ("ctrl-w h", "FocusSidebar"),
+    // Session scrollback
+    ("pageup", "ScrollPanePageUp"),
+    ("pagedown", "ScrollPanePageDown"),
     // Chrome
     ("ctrl-w b", "ToggleSidebar"),
     ("?", "ShowHelp"),
     ("ctrl-w q", "Quit"),
     // Mouse
     ("mouse:dblclick(sidebar-row)", "AttachHighlighted"),
-    ("mouse:click(tab)", "NextTab"),
 ];
 
 /// Default Insert-mode bindings. Empty by default — the only Insert binding
@@ -76,6 +77,20 @@ impl TuiConfig {
     /// field of the loaded `MaestroConfigFile`). The shipped defaults are
     /// applied first, then user overrides on top.
     pub fn load(section: &TuiSection) -> Result<Self, TuiConfigError> {
+        let palette = match section.theme.unwrap_or(TuiTheme::Dark) {
+            TuiTheme::Dark => Palette::DARK,
+            TuiTheme::Light => Palette::LIGHT,
+            TuiTheme::Ansi => Palette::ANSI,
+            TuiTheme::SolarizedDark => Palette::SOLARIZED_DARK,
+            TuiTheme::SolarizedLight => Palette::SOLARIZED_LIGHT,
+            TuiTheme::Catppuccin => Palette::CATPPUCCIN,
+            TuiTheme::GithubDark => Palette::GITHUB_DARK,
+            TuiTheme::GithubLight => Palette::GITHUB_LIGHT,
+            TuiTheme::TokyoNight => Palette::TOKYO_NIGHT,
+            TuiTheme::Gruvbox => Palette::GRUVBOX,
+            TuiTheme::Nord => Palette::NORD,
+            TuiTheme::Dracula => Palette::DRACULA,
+        };
         let leader_str = section.leader.as_deref().unwrap_or("ctrl-a");
         let leader = InputKey::parse(leader_str)
             .map_err(|_| TuiConfigError::BadLeader(leader_str.to_string()))?;
@@ -131,6 +146,7 @@ impl TuiConfig {
         }
 
         Ok(TuiConfig {
+            palette,
             leader,
             chord_timeout,
             keymap,
@@ -143,6 +159,37 @@ impl TuiConfig {
 mod tests {
     use super::*;
     use crate::action::Action;
+    use maestro_config::{TuiSection, TuiTheme};
+
+    #[test]
+    fn absent_theme_selects_the_dark_default() {
+        let cfg = TuiConfig::load(&TuiSection::default()).unwrap();
+        assert_eq!(cfg.palette, Palette::DARK);
+    }
+
+    #[test]
+    fn named_themes_select_the_matching_complete_palette() {
+        for (theme, expected) in [
+            (TuiTheme::Dark, Palette::DARK),
+            (TuiTheme::Light, Palette::LIGHT),
+            (TuiTheme::Ansi, Palette::ANSI),
+            (TuiTheme::SolarizedDark, Palette::SOLARIZED_DARK),
+            (TuiTheme::SolarizedLight, Palette::SOLARIZED_LIGHT),
+            (TuiTheme::Catppuccin, Palette::CATPPUCCIN),
+            (TuiTheme::GithubDark, Palette::GITHUB_DARK),
+            (TuiTheme::GithubLight, Palette::GITHUB_LIGHT),
+            (TuiTheme::TokyoNight, Palette::TOKYO_NIGHT),
+            (TuiTheme::Gruvbox, Palette::GRUVBOX),
+            (TuiTheme::Nord, Palette::NORD),
+            (TuiTheme::Dracula, Palette::DRACULA),
+        ] {
+            let section = TuiSection {
+                theme: Some(theme),
+                ..Default::default()
+            };
+            assert_eq!(TuiConfig::load(&section).unwrap().palette, expected);
+        }
+    }
 
     #[test]
     fn defaults_cover_core_actions() {
@@ -155,10 +202,6 @@ mod tests {
             cfg.keymap.resolve(Mode::Normal, "enter"),
             Some(Action::AttachHighlighted),
         );
-        assert_eq!(
-            cfg.keymap.resolve(Mode::Normal, "g t"),
-            Some(Action::NextTab),
-        );
         assert_eq!(
             cfg.keymap.resolve(Mode::Normal, "s"),
             Some(Action::NewDraftPane),

crates/maestro-tui/src/input.rs

@@ -36,6 +36,8 @@ pub enum InputKey {
     Right,
     Home,
     End,
+    PageUp,
+    PageDown,
     Delete,
     /// Bracketed paste: crossterm delivers the whole payload as one event, so
     /// text fields can insert it as a single operation.
@@ -63,7 +65,6 @@ pub enum MouseKind {
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum Region {
     SidebarRow,
-    Tab,
     Pane,
     Modal,
     Unknown,
@@ -136,6 +137,8 @@ impl InputKey {
             InputKey::Right => "right".into(),
             InputKey::Home => "home".into(),
             InputKey::End => "end".into(),
+            InputKey::PageUp => "pageup".into(),
+            InputKey::PageDown => "pagedown".into(),
             InputKey::Delete => "delete".into(),
             // Pastes are not bindable; the canonical form exists only to
             // satisfy exhaustiveness and never round-trips through `parse`.
@@ -150,7 +153,6 @@ impl InputKey {
                 };
                 let r = match region {
                     Region::SidebarRow => "sidebar-row",
-                    Region::Tab => "tab",
                     Region::Pane => "pane",
                     Region::Modal => "modal",
                     Region::Unknown => "unknown",
@@ -182,7 +184,6 @@ impl InputKey {
             };
             let region = match r {
                 "sidebar-row" => Region::SidebarRow,
-                "tab" => Region::Tab,
                 "pane" => Region::Pane,
                 "modal" => Region::Modal,
                 "unknown" => Region::Unknown,
@@ -207,6 +208,8 @@ impl InputKey {
             "right" => return Ok(InputKey::Right),
             "home" => return Ok(InputKey::Home),
             "end" => return Ok(InputKey::End),
+            "pageup" => return Ok(InputKey::PageUp),
+            "pagedown" => return Ok(InputKey::PageDown),
             "delete" => return Ok(InputKey::Delete),
             _ => {}
         }
@@ -281,6 +284,8 @@ where
                 KeyCode::Right => InputKey::Right,
                 KeyCode::Home => InputKey::Home,
                 KeyCode::End => InputKey::End,
+                KeyCode::PageUp => InputKey::PageUp,
+                KeyCode::PageDown => InputKey::PageDown,
                 KeyCode::Delete => InputKey::Delete,
                 _ => return None,
             })
@@ -617,6 +622,8 @@ mod tests {
             "right",
             "home",
             "end",
+            "pageup",
+            "pagedown",
             "delete",
         ] {
             let k = InputKey::parse(s).unwrap();

crates/maestro-tui/src/keymap.rs

@@ -107,8 +107,8 @@ mod tests {
 
     #[test]
     fn resolves_chord() {
-        let k = build(&[(Mode::Normal, "g t", "NextTab")]);
+        let k = build(&[(Mode::Normal, "g h", "FocusSidebar")]);
-        assert_eq!(k.resolve(Mode::Normal, "g t"), Some(Action::NextTab));
+        assert_eq!(k.resolve(Mode::Normal, "g h"), Some(Action::FocusSidebar));
     }
 
     #[test]
@@ -123,11 +123,11 @@ mod tests {
     #[test]
     fn known_bindings_sees_everything() {
         let k = build(&[
-            (Mode::Normal, "g t", "NextTab"),
+            (Mode::Normal, "g h", "FocusSidebar"),
             (Mode::Normal, "i", "EnterInsert"),
         ]);
         let kb = k.known_bindings(Mode::Normal);
-        assert!(kb.contains("g t"));
+        assert!(kb.contains("g h"));
         assert!(kb.contains("i"));
         assert_eq!(kb.len(), 2);
     }

crates/maestro-tui/src/lib.rs

@@ -13,13 +13,13 @@ pub mod fast_forward;
 pub mod input;
 pub mod keymap;
 pub mod overlays;
+pub mod palette;
 pub mod pane;
 pub mod projects;
 pub mod render;
 pub mod session_task;
 pub mod sidebar;
 pub mod state;
-pub mod tabs;
 pub mod terminal;
 pub mod text_input;
 pub mod worktrees;
@@ -89,6 +89,7 @@ pub async fn run(cfg: RunConfig) -> Result<(), TuiError> {
         Err(_) => maestro_config::MaestroConfigFile::default(),
     };
     let tui_cfg = TuiConfig::load(&cfg_file.tui).map_err(|e| TuiError::Config(e.to_string()))?;
+    palette::set_active(tui_cfg.palette);
 
     let catalog = CatalogStore::default();
     let ws_url = daemon

crates/maestro-tui/src/overlays.rs

@@ -155,12 +155,12 @@ mod tests {
     fn help_overlay_lists_lines() {
         let help = HelpOverlay {
             lines: vec![
-                "i           EnterInsert".into(),
+                "i           Send keys to session".into(),
-                "s           NewDraftPane".into(),
+                "s           Create a session".into(),
             ],
         };
         let rendered = render_to_string(80, 12, |f| help.render(f, f.area()));
-        assert!(rendered.contains("EnterInsert"));
+        assert!(rendered.contains("Send keys to session"));
-        assert!(rendered.contains("NewDraftPane"));
+        assert!(rendered.contains("Create a session"));
     }
 }

crates/maestro-tui/src/palette.rs

@@ -0,0 +1,851 @@
+//! Named colour roles for the TUI.
+//!
+//! Every colour the TUI paints on its own chrome comes from here, named for
+//! what it means rather than what it looks like: the card surface, the
+//! selection surface, the panel border in its focused and unfocused forms,
+//! the text weights (`fg` / `muted` / `dim`), and one role per
+//! [`ActivityState`]. Call sites ask the palette for a role; they never spell
+//! a colour out.
+//!
+//! Values are [`Color::Rgb`], so contrast is a property of the palette rather
+//! than of the user's terminal theme — and can therefore be asserted (see
+//! [`contrast_ratio`] and this module's tests).
+//!
+//! Each surface carries its own activity colours. A state colour picked for
+//! the dark card background is not legible on the selection background, so
+//! the selected card uses the selection surface's own state colours; the dot
+//! keeps carrying the state either way (docs/SIDEBAR.md).
+//!
+//! [`Palette::DARK`] is the default. [`Palette::LIGHT`] is its light peer and
+//! [`Palette::ANSI`] uses terminal-provided ANSI colours. The remaining
+//! presets ([`Palette::presets`]) adapt well-known editor themes — Solarized,
+//! Catppuccin, GitHub, Tokyo Night, Gruvbox, Nord, Dracula — with individual
+//! colours lifted or darkened where the originals fall short of the contrast
+//! floors asserted below.
+//!
+//! Out of scope: PTY cell colours. Those belong to the program running in the
+//! pane and pass through `pane::translate_color` verbatim.
+
+use maestro_protocol::ActivityState;
+use ratatui::style::{Color, Modifier, Style};
+
+/// A background and the foreground roles legible on it.
+///
+/// The sidebar has two: the card surface every card sits on, and the
+/// selection surface the highlighted card swaps in.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct Surface {
+    /// The surface itself.
+    pub bg: Color,
+    /// Primary text on this surface.
+    pub fg: Color,
+    /// Secondary text — the blocked-work, exited, detail and command
+    /// fragments of a card's meta line.
+    pub muted: Color,
+    /// The quietest legible text on this surface, for decoration that must
+    /// not compete with content.
+    pub dim: Color,
+    /// `ActivityState::Active`.
+    pub active: Color,
+    /// `ActivityState::Idle`.
+    pub idle: Color,
+    /// `ActivityState::AwaitingInput`.
+    pub awaiting: Color,
+    /// `ActivityState::Error`.
+    pub error: Color,
+}
+
+impl Surface {
+    /// The bare surface: a background with no foreground override.
+    pub fn base(&self) -> Style {
+        Style::default().bg(self.bg)
+    }
+
+    /// Primary text on this surface.
+    pub fn text_style(&self) -> Style {
+        Style::default().bg(self.bg).fg(self.fg)
+    }
+
+    /// Secondary text on this surface.
+    pub fn muted_style(&self) -> Style {
+        Style::default().bg(self.bg).fg(self.muted)
+    }
+
+    /// The quietest text on this surface.
+    pub fn dim_style(&self) -> Style {
+        Style::default().bg(self.bg).fg(self.dim)
+    }
+
+    /// The colour carrying `state` on this surface.
+    pub fn activity(&self, state: ActivityState) -> Color {
+        match state {
+            ActivityState::Active => self.active,
+            ActivityState::Idle => self.idle,
+            ActivityState::AwaitingInput => self.awaiting,
+            ActivityState::Error => self.error,
+        }
+    }
+
+    /// Every foreground role on this surface, paired with its role name.
+    /// Used by the contrast tests, and by anything that needs to reason about
+    /// the surface as a whole.
+    pub fn roles(&self) -> [(&'static str, Color); 7] {
+        [
+            ("fg", self.fg),
+            ("muted", self.muted),
+            ("dim", self.dim),
+            ("active", self.active),
+            ("idle", self.idle),
+            ("awaiting", self.awaiting),
+            ("error", self.error),
+        ]
+    }
+}
+
+/// The full set of colour roles the TUI paints with.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct Palette {
+    /// The surface an unselected card sits on.
+    pub card: Surface,
+    /// The surface the highlighted card swaps in.
+    pub selection: Surface,
+    /// Background for TUI-owned chrome outside cards. Fixed-RGB chrome must
+    /// paint this background too; otherwise its contrast depends on the
+    /// operator's terminal theme.
+    pub chrome_bg: Color,
+    /// Subtle full-panel background while the sidebar owns focus.
+    pub sidebar_focus_bg: Color,
+    /// Panel border while that panel holds focus.
+    pub border_focused: Color,
+    /// Panel border while it does not.
+    pub border_unfocused: Color,
+    /// Focus affordances that are not the border itself — markers, titles and
+    /// the like on the panel that holds focus.
+    pub focus_accent: Color,
+    /// Sidebar group headings.
+    pub group_row: Color,
+    /// Status-bar mode indicator, normal mode.
+    pub mode_normal_bg: Color,
+    pub mode_normal_fg: Color,
+    /// Status-bar mode indicator, insert mode.
+    pub mode_insert_bg: Color,
+    pub mode_insert_fg: Color,
+    /// Error text outside a card — form errors, failed actions.
+    pub error_text: Color,
+}
+
+impl Palette {
+    /// The dark terminal-native palette and the default preset.
+    pub const DARK: Palette = Palette {
+        card: Surface {
+            bg: Color::Rgb(0x1f, 0x23, 0x2b),
+            fg: Color::Rgb(0xe5, 0xe7, 0xeb),
+            muted: Color::Rgb(0xae, 0xb7, 0xc4),
+            dim: Color::Rgb(0x85, 0x8f, 0x9e),
+            active: Color::Rgb(0x72, 0xd6, 0x87),
+            idle: Color::Rgb(0xae, 0xb7, 0xc4),
+            awaiting: Color::Rgb(0xf2, 0xc9, 0x5c),
+            error: Color::Rgb(0xff, 0x82, 0x7a),
+        },
+        selection: Surface {
+            bg: Color::Rgb(0x3d, 0x51, 0x44),
+            fg: Color::Rgb(0xf3, 0xf7, 0xf4),
+            muted: Color::Rgb(0xd0, 0xd9, 0xd3),
+            dim: Color::Rgb(0xa1, 0xb0, 0xa6),
+            active: Color::Rgb(0x9a, 0xf0, 0xa6),
+            idle: Color::Rgb(0xc4, 0xcf, 0xc7),
+            awaiting: Color::Rgb(0xf6, 0xd9, 0x78),
+            error: Color::Rgb(0xff, 0xa8, 0xa3),
+        },
+        chrome_bg: Color::Rgb(0x1f, 0x23, 0x2b),
+        sidebar_focus_bg: Color::Rgb(0x28, 0x30, 0x2a),
+        border_focused: Color::Rgb(0x72, 0xd6, 0x87),
+        border_unfocused: Color::Rgb(0x68, 0x73, 0x84),
+        focus_accent: Color::Rgb(0x72, 0xd6, 0x87),
+        group_row: Color::Rgb(0xb6, 0xc1, 0xd3),
+        mode_normal_bg: Color::Rgb(0x72, 0xd6, 0x87),
+        mode_normal_fg: Color::Rgb(0x1f, 0x23, 0x2b),
+        mode_insert_bg: Color::Rgb(0xf2, 0xc9, 0x5c),
+        mode_insert_fg: Color::Rgb(0x1f, 0x23, 0x2b),
+        error_text: Color::Rgb(0xff, 0x82, 0x7a),
+    };
+
+    /// A high-contrast light peer to [`Self::DARK`].
+    pub const LIGHT: Palette = Palette {
+        card: Surface {
+            bg: Color::Rgb(0xff, 0xff, 0xff),
+            fg: Color::Rgb(0x27, 0x31, 0x3d),
+            muted: Color::Rgb(0x4c, 0x5b, 0x6b),
+            dim: Color::Rgb(0x68, 0x78, 0x8a),
+            active: Color::Rgb(0x21, 0x7a, 0x3c),
+            idle: Color::Rgb(0x4c, 0x5b, 0x6b),
+            awaiting: Color::Rgb(0x8f, 0x63, 0x00),
+            error: Color::Rgb(0xb4, 0x23, 0x18),
+        },
+        selection: Surface {
+            bg: Color::Rgb(0xb5, 0xcf, 0xba),
+            fg: Color::Rgb(0x1d, 0x2a, 0x24),
+            muted: Color::Rgb(0x3f, 0x55, 0x45),
+            dim: Color::Rgb(0x52, 0x68, 0x5a),
+            active: Color::Rgb(0x15, 0x5b, 0x2e),
+            idle: Color::Rgb(0x3f, 0x55, 0x45),
+            awaiting: Color::Rgb(0x69, 0x46, 0x00),
+            error: Color::Rgb(0xa5, 0x1d, 0x14),
+        },
+        chrome_bg: Color::Rgb(0xff, 0xff, 0xff),
+        sidebar_focus_bg: Color::Rgb(0xee, 0xf5, 0xef),
+        border_focused: Color::Rgb(0x21, 0x7a, 0x3c),
+        border_unfocused: Color::Rgb(0x65, 0x73, 0x6b),
+        focus_accent: Color::Rgb(0x21, 0x7a, 0x3c),
+        group_row: Color::Rgb(0x3f, 0x55, 0x45),
+        mode_normal_bg: Color::Rgb(0x21, 0x7a, 0x3c),
+        mode_normal_fg: Color::Rgb(0xff, 0xff, 0xff),
+        mode_insert_bg: Color::Rgb(0xb6, 0x81, 0x08),
+        mode_insert_fg: Color::Rgb(0x0b, 0x12, 0x0e),
+        error_text: Color::Rgb(0xb4, 0x23, 0x18),
+    };
+
+    /// A palette of named ANSI colours for terminals without truecolour.
+    pub const ANSI: Palette = Palette {
+        card: Surface {
+            bg: Color::Black,
+            fg: Color::White,
+            muted: Color::Gray,
+            dim: Color::DarkGray,
+            active: Color::Green,
+            idle: Color::Gray,
+            awaiting: Color::Yellow,
+            error: Color::Red,
+        },
+        selection: Surface {
+            bg: Color::Blue,
+            fg: Color::White,
+            muted: Color::White,
+            dim: Color::LightBlue,
+            active: Color::LightGreen,
+            idle: Color::White,
+            awaiting: Color::LightYellow,
+            error: Color::LightRed,
+        },
+        chrome_bg: Color::Black,
+        sidebar_focus_bg: Color::DarkGray,
+        border_focused: Color::LightGreen,
+        border_unfocused: Color::DarkGray,
+        focus_accent: Color::LightGreen,
+        group_row: Color::LightCyan,
+        mode_normal_bg: Color::Green,
+        mode_normal_fg: Color::Black,
+        mode_insert_bg: Color::Yellow,
+        mode_insert_fg: Color::Black,
+        error_text: Color::LightRed,
+    };
+
+    /// Solarized Dark — Ethan Schoonover's low-contrast classic,
+    /// accents lifted where the originals fall short of WCAG AA.
+    pub const SOLARIZED_DARK: Palette = Palette {
+        card: Surface {
+            bg: Color::Rgb(0x00, 0x2b, 0x36),
+            fg: Color::Rgb(0x93, 0xa1, 0xa1),
+            muted: Color::Rgb(0x83, 0x94, 0x96),
+            dim: Color::Rgb(0x65, 0x7b, 0x83),
+            active: Color::Rgb(0x85, 0x99, 0x00),
+            idle: Color::Rgb(0x83, 0x94, 0x96),
+            awaiting: Color::Rgb(0xb5, 0x89, 0x00),
+            error: Color::Rgb(0xe5, 0x68, 0x65),
+        },
+        selection: Surface {
+            bg: Color::Rgb(0x10, 0x53, 0x62),
+            fg: Color::Rgb(0xb6, 0xc0, 0xc0),
+            muted: Color::Rgb(0xb5, 0xc0, 0xc1),
+            dim: Color::Rgb(0x8b, 0x9f, 0xa6),
+            active: Color::Rgb(0xaf, 0xca, 0x00),
+            idle: Color::Rgb(0xb5, 0xc0, 0xc1),
+            awaiting: Color::Rgb(0xef, 0xb5, 0x00),
+            error: Color::Rgb(0xf1, 0xad, 0xab),
+        },
+        chrome_bg: Color::Rgb(0x00, 0x2b, 0x36),
+        sidebar_focus_bg: Color::Rgb(0x00, 0x1a, 0x21),
+        border_focused: Color::Rgb(0x2a, 0xa1, 0x98),
+        border_unfocused: Color::Rgb(0x5e, 0x76, 0x7e),
+        focus_accent: Color::Rgb(0x2a, 0xa1, 0x98),
+        group_row: Color::Rgb(0x93, 0xa1, 0xa1),
+        mode_normal_bg: Color::Rgb(0x2a, 0xa1, 0x98),
+        mode_normal_fg: Color::Rgb(0x00, 0x2b, 0x36),
+        mode_insert_bg: Color::Rgb(0xb5, 0x89, 0x00),
+        mode_insert_fg: Color::Rgb(0x00, 0x2b, 0x36),
+        error_text: Color::Rgb(0xe5, 0x68, 0x65),
+    };
+
+    /// Solarized Light — the warm cream-paper peer of Solarized Dark.
+    pub const SOLARIZED_LIGHT: Palette = Palette {
+        card: Surface {
+            bg: Color::Rgb(0xfd, 0xf6, 0xe3),
+            fg: Color::Rgb(0x58, 0x6e, 0x75),
+            muted: Color::Rgb(0x5e, 0x73, 0x7a),
+            dim: Color::Rgb(0x7e, 0x8f, 0x92),
+            active: Color::Rgb(0x67, 0x76, 0x00),
+            idle: Color::Rgb(0x5e, 0x73, 0x7a),
+            awaiting: Color::Rgb(0x8d, 0x6a, 0x00),
+            error: Color::Rgb(0xd7, 0x27, 0x24),
+        },
+        selection: Surface {
+            bg: Color::Rgb(0xcb, 0xbd, 0x93),
+            fg: Color::Rgb(0x3f, 0x4e, 0x53),
+            muted: Color::Rgb(0x40, 0x4e, 0x53),
+            dim: Color::Rgb(0x59, 0x67, 0x69),
+            active: Color::Rgb(0x46, 0x50, 0x00),
+            idle: Color::Rgb(0x40, 0x4e, 0x53),
+            awaiting: Color::Rgb(0x60, 0x48, 0x00),
+            error: Color::Rgb(0x94, 0x1b, 0x19),
+        },
+        chrome_bg: Color::Rgb(0xfd, 0xf6, 0xe3),
+        sidebar_focus_bg: Color::Rgb(0xf7, 0xf4, 0xed),
+        border_focused: Color::Rgb(0x29, 0x9b, 0x93),
+        border_unfocused: Color::Rgb(0x7f, 0x8f, 0x8f),
+        focus_accent: Color::Rgb(0x29, 0x9b, 0x93),
+        group_row: Color::Rgb(0x58, 0x6e, 0x75),
+        mode_normal_bg: Color::Rgb(0x2a, 0xa1, 0x98),
+        mode_normal_fg: Color::Rgb(0x00, 0x2b, 0x36),
+        mode_insert_bg: Color::Rgb(0x8d, 0x6a, 0x00),
+        mode_insert_fg: Color::Rgb(0xfd, 0xf6, 0xe3),
+        error_text: Color::Rgb(0xd7, 0x27, 0x24),
+    };
+
+    /// Catppuccin Mocha — soothing pastels on a soft dark base.
+    pub const CATPPUCCIN: Palette = Palette {
+        card: Surface {
+            bg: Color::Rgb(0x1e, 0x1e, 0x2e),
+            fg: Color::Rgb(0xcd, 0xd6, 0xf4),
+            muted: Color::Rgb(0xa6, 0xad, 0xc8),
+            dim: Color::Rgb(0x7f, 0x84, 0x9c),
+            active: Color::Rgb(0xa6, 0xe3, 0xa1),
+            idle: Color::Rgb(0xa6, 0xad, 0xc8),
+            awaiting: Color::Rgb(0xf9, 0xe2, 0xaf),
+            error: Color::Rgb(0xf3, 0x8b, 0xa8),
+        },
+        selection: Surface {
+            bg: Color::Rgb(0x45, 0x47, 0x5a),
+            fg: Color::Rgb(0xcd, 0xd6, 0xf4),
+            muted: Color::Rgb(0xb2, 0xb8, 0xcf),
+            dim: Color::Rgb(0x92, 0x97, 0xab),
+            active: Color::Rgb(0xb5, 0xe8, 0xb1),
+            idle: Color::Rgb(0xb2, 0xb8, 0xcf),
+            awaiting: Color::Rgb(0xfa, 0xe9, 0xc2),
+            error: Color::Rgb(0xf5, 0xa1, 0xb8),
+        },
+        chrome_bg: Color::Rgb(0x1e, 0x1e, 0x2e),
+        sidebar_focus_bg: Color::Rgb(0x2a, 0x2a, 0x3c),
+        border_focused: Color::Rgb(0xcb, 0xa6, 0xf7),
+        border_unfocused: Color::Rgb(0x6c, 0x70, 0x86),
+        focus_accent: Color::Rgb(0xcb, 0xa6, 0xf7),
+        group_row: Color::Rgb(0xb4, 0xbe, 0xfe),
+        mode_normal_bg: Color::Rgb(0xcb, 0xa6, 0xf7),
+        mode_normal_fg: Color::Rgb(0x1e, 0x1e, 0x2e),
+        mode_insert_bg: Color::Rgb(0xf9, 0xe2, 0xaf),
+        mode_insert_fg: Color::Rgb(0x1e, 0x1e, 0x2e),
+        error_text: Color::Rgb(0xf3, 0x8b, 0xa8),
+    };
+
+    /// GitHub Dark — the github.com dark default.
+    pub const GITHUB_DARK: Palette = Palette {
+        card: Surface {
+            bg: Color::Rgb(0x0d, 0x11, 0x17),
+            fg: Color::Rgb(0xe6, 0xed, 0xf3),
+            muted: Color::Rgb(0x91, 0x98, 0xa1),
+            dim: Color::Rgb(0x6e, 0x76, 0x81),
+            active: Color::Rgb(0x3f, 0xb9, 0x50),
+            idle: Color::Rgb(0x91, 0x98, 0xa1),
+            awaiting: Color::Rgb(0xd2, 0x99, 0x22),
+            error: Color::Rgb(0xf8, 0x51, 0x49),
+        },
+        selection: Surface {
+            bg: Color::Rgb(0x1f, 0x3a, 0x5f),
+            fg: Color::Rgb(0xe6, 0xed, 0xf3),
+            muted: Color::Rgb(0x9f, 0xa5, 0xad),
+            dim: Color::Rgb(0x7e, 0x86, 0x91),
+            active: Color::Rgb(0x40, 0xbc, 0x51),
+            idle: Color::Rgb(0x9f, 0xa5, 0xad),
+            awaiting: Color::Rgb(0xd4, 0x9b, 0x22),
+            error: Color::Rgb(0xfa, 0x81, 0x7b),
+        },
+        chrome_bg: Color::Rgb(0x0d, 0x11, 0x17),
+        sidebar_focus_bg: Color::Rgb(0x16, 0x1b, 0x26),
+        border_focused: Color::Rgb(0x58, 0xa6, 0xff),
+        border_unfocused: Color::Rgb(0x58, 0x64, 0x70),
+        focus_accent: Color::Rgb(0x58, 0xa6, 0xff),
+        group_row: Color::Rgb(0x91, 0x98, 0xa1),
+        mode_normal_bg: Color::Rgb(0x58, 0xa6, 0xff),
+        mode_normal_fg: Color::Rgb(0x0d, 0x11, 0x17),
+        mode_insert_bg: Color::Rgb(0xd2, 0x99, 0x22),
+        mode_insert_fg: Color::Rgb(0x0d, 0x11, 0x17),
+        error_text: Color::Rgb(0xf8, 0x51, 0x49),
+    };
+
+    /// GitHub Light — the github.com light default.
+    pub const GITHUB_LIGHT: Palette = Palette {
+        card: Surface {
+            bg: Color::Rgb(0xff, 0xff, 0xff),
+            fg: Color::Rgb(0x1f, 0x23, 0x28),
+            muted: Color::Rgb(0x59, 0x63, 0x6e),
+            dim: Color::Rgb(0x81, 0x8b, 0x98),
+            active: Color::Rgb(0x1a, 0x7f, 0x37),
+            idle: Color::Rgb(0x59, 0x63, 0x6e),
+            awaiting: Color::Rgb(0x9a, 0x67, 0x00),
+            error: Color::Rgb(0xd1, 0x24, 0x2f),
+        },
+        selection: Surface {
+            bg: Color::Rgb(0xa5, 0xcd, 0xf0),
+            fg: Color::Rgb(0x1f, 0x23, 0x28),
+            muted: Color::Rgb(0x4b, 0x53, 0x5d),
+            dim: Color::Rgb(0x64, 0x6d, 0x7a),
+            active: Color::Rgb(0x14, 0x5f, 0x29),
+            idle: Color::Rgb(0x4b, 0x53, 0x5d),
+            awaiting: Color::Rgb(0x71, 0x4b, 0x00),
+            error: Color::Rgb(0xa1, 0x1c, 0x24),
+        },
+        chrome_bg: Color::Rgb(0xff, 0xff, 0xff),
+        sidebar_focus_bg: Color::Rgb(0xf0, 0xf6, 0xfc),
+        border_focused: Color::Rgb(0x09, 0x69, 0xda),
+        border_unfocused: Color::Rgb(0x89, 0x93, 0x9d),
+        focus_accent: Color::Rgb(0x09, 0x69, 0xda),
+        group_row: Color::Rgb(0x59, 0x63, 0x6e),
+        mode_normal_bg: Color::Rgb(0x09, 0x69, 0xda),
+        mode_normal_fg: Color::Rgb(0xff, 0xff, 0xff),
+        mode_insert_bg: Color::Rgb(0x9a, 0x67, 0x00),
+        mode_insert_fg: Color::Rgb(0xff, 0xff, 0xff),
+        error_text: Color::Rgb(0xd1, 0x24, 0x2f),
+    };
+
+    /// Tokyo Night — neon-tinted blues of the VS Code / vim favourite.
+    pub const TOKYO_NIGHT: Palette = Palette {
+        card: Surface {
+            bg: Color::Rgb(0x1a, 0x1b, 0x26),
+            fg: Color::Rgb(0xc0, 0xca, 0xf5),
+            muted: Color::Rgb(0xa9, 0xb1, 0xd6),
+            dim: Color::Rgb(0x5d, 0x67, 0x95),
+            active: Color::Rgb(0x9e, 0xce, 0x6a),
+            idle: Color::Rgb(0xa9, 0xb1, 0xd6),
+            awaiting: Color::Rgb(0xe0, 0xaf, 0x68),
+            error: Color::Rgb(0xf7, 0x76, 0x8e),
+        },
+        selection: Surface {
+            bg: Color::Rgb(0x33, 0x46, 0x7c),
+            fg: Color::Rgb(0xc0, 0xca, 0xf5),
+            muted: Color::Rgb(0xb0, 0xb8, 0xd9),
+            dim: Color::Rgb(0x8e, 0x96, 0xb8),
+            active: Color::Rgb(0xa8, 0xd3, 0x79),
+            idle: Color::Rgb(0xb0, 0xb8, 0xd9),
+            awaiting: Color::Rgb(0xe1, 0xb1, 0x6b),
+            error: Color::Rgb(0xf9, 0xa0, 0xb0),
+        },
+        chrome_bg: Color::Rgb(0x1a, 0x1b, 0x26),
+        sidebar_focus_bg: Color::Rgb(0x24, 0x28, 0x3b),
+        border_focused: Color::Rgb(0x7a, 0xa2, 0xf7),
+        border_unfocused: Color::Rgb(0x5d, 0x67, 0x95),
+        focus_accent: Color::Rgb(0x7a, 0xa2, 0xf7),
+        group_row: Color::Rgb(0xa9, 0xb1, 0xd6),
+        mode_normal_bg: Color::Rgb(0x7a, 0xa2, 0xf7),
+        mode_normal_fg: Color::Rgb(0x1a, 0x1b, 0x26),
+        mode_insert_bg: Color::Rgb(0xe0, 0xaf, 0x68),
+        mode_insert_fg: Color::Rgb(0x1a, 0x1b, 0x26),
+        error_text: Color::Rgb(0xf7, 0x76, 0x8e),
+    };
+
+    /// Gruvbox Dark — retro warm earth tones.
+    pub const GRUVBOX: Palette = Palette {
+        card: Surface {
+            bg: Color::Rgb(0x28, 0x28, 0x28),
+            fg: Color::Rgb(0xeb, 0xdb, 0xb2),
+            muted: Color::Rgb(0xbd, 0xae, 0x93),
+            dim: Color::Rgb(0x92, 0x83, 0x74),
+            active: Color::Rgb(0xb8, 0xbb, 0x26),
+            idle: Color::Rgb(0xbd, 0xae, 0x93),
+            awaiting: Color::Rgb(0xfa, 0xbd, 0x2f),
+            error: Color::Rgb(0xfb, 0x58, 0x44),
+        },
+        selection: Surface {
+            bg: Color::Rgb(0x50, 0x49, 0x45),
+            fg: Color::Rgb(0xeb, 0xdb, 0xb2),
+            muted: Color::Rgb(0xc7, 0xbb, 0xa4),
+            dim: Color::Rgb(0xa4, 0x98, 0x8b),
+            active: Color::Rgb(0xbf, 0xc3, 0x28),
+            idle: Color::Rgb(0xc7, 0xbb, 0xa4),
+            awaiting: Color::Rgb(0xfa, 0xc3, 0x43),
+            error: Color::Rgb(0xfd, 0xa5, 0x9a),
+        },
+        chrome_bg: Color::Rgb(0x28, 0x28, 0x28),
+        sidebar_focus_bg: Color::Rgb(0x32, 0x30, 0x2f),
+        border_focused: Color::Rgb(0xfe, 0x80, 0x19),
+        border_unfocused: Color::Rgb(0x7e, 0x71, 0x67),
+        focus_accent: Color::Rgb(0xfe, 0x80, 0x19),
+        group_row: Color::Rgb(0xd5, 0xc4, 0xa1),
+        mode_normal_bg: Color::Rgb(0xfe, 0x80, 0x19),
+        mode_normal_fg: Color::Rgb(0x28, 0x28, 0x28),
+        mode_insert_bg: Color::Rgb(0xfa, 0xbd, 0x2f),
+        mode_insert_fg: Color::Rgb(0x28, 0x28, 0x28),
+        error_text: Color::Rgb(0xfb, 0x58, 0x44),
+    };
+
+    /// Nord — arctic, bluish and calm; the red lifted to stay legible.
+    pub const NORD: Palette = Palette {
+        card: Surface {
+            bg: Color::Rgb(0x2e, 0x34, 0x40),
+            fg: Color::Rgb(0xec, 0xef, 0xf4),
+            muted: Color::Rgb(0xd8, 0xde, 0xe9),
+            dim: Color::Rgb(0x9a, 0xa5, 0xb5),
+            active: Color::Rgb(0xa3, 0xbe, 0x8c),
+            idle: Color::Rgb(0xd8, 0xde, 0xe9),
+            awaiting: Color::Rgb(0xeb, 0xcb, 0x8b),
+            error: Color::Rgb(0xd0, 0x8b, 0x91),
+        },
+        selection: Surface {
+            bg: Color::Rgb(0x4c, 0x56, 0x6a),
+            fg: Color::Rgb(0xec, 0xef, 0xf4),
+            muted: Color::Rgb(0xd8, 0xde, 0xe9),
+            dim: Color::Rgb(0x9f, 0xaa, 0xb9),
+            active: Color::Rgb(0xc0, 0xd3, 0xb0),
+            idle: Color::Rgb(0xe5, 0xe9, 0xf0),
+            awaiting: Color::Rgb(0xee, 0xd3, 0x9c),
+            error: Color::Rgb(0xe7, 0xc5, 0xc8),
+        },
+        chrome_bg: Color::Rgb(0x2e, 0x34, 0x40),
+        sidebar_focus_bg: Color::Rgb(0x35, 0x3b, 0x49),
+        border_focused: Color::Rgb(0x88, 0xc0, 0xd0),
+        border_unfocused: Color::Rgb(0x72, 0x80, 0x9a),
+        focus_accent: Color::Rgb(0x88, 0xc0, 0xd0),
+        group_row: Color::Rgb(0xd8, 0xde, 0xe9),
+        mode_normal_bg: Color::Rgb(0x88, 0xc0, 0xd0),
+        mode_normal_fg: Color::Rgb(0x2e, 0x34, 0x40),
+        mode_insert_bg: Color::Rgb(0xeb, 0xcb, 0x8b),
+        mode_insert_fg: Color::Rgb(0x2e, 0x34, 0x40),
+        error_text: Color::Rgb(0xd0, 0x8b, 0x91),
+    };
+
+    /// Dracula — high-saturation accents on a dark violet-grey base.
+    pub const DRACULA: Palette = Palette {
+        card: Surface {
+            bg: Color::Rgb(0x28, 0x2a, 0x36),
+            fg: Color::Rgb(0xf8, 0xf8, 0xf2),
+            muted: Color::Rgb(0xbf, 0xc3, 0xd9),
+            dim: Color::Rgb(0x65, 0x74, 0xa6),
+            active: Color::Rgb(0x50, 0xfa, 0x7b),
+            idle: Color::Rgb(0xbf, 0xc3, 0xd9),
+            awaiting: Color::Rgb(0xf1, 0xfa, 0x8c),
+            error: Color::Rgb(0xff, 0x59, 0x59),
+        },
+        selection: Surface {
+            bg: Color::Rgb(0x4a, 0x4e, 0x62),
+            fg: Color::Rgb(0xf8, 0xf8, 0xf2),
+            muted: Color::Rgb(0xbf, 0xc3, 0xd9),
+            dim: Color::Rgb(0x94, 0x9f, 0xc1),
+            active: Color::Rgb(0x64, 0xfb, 0x8a),
+            idle: Color::Rgb(0xcc, 0xcf, 0xe1),
+            awaiting: Color::Rgb(0xf3, 0xfb, 0xa0),
+            error: Color::Rgb(0xff, 0xad, 0xad),
+        },
+        chrome_bg: Color::Rgb(0x28, 0x2a, 0x36),
+        sidebar_focus_bg: Color::Rgb(0x31, 0x33, 0x42),
+        border_focused: Color::Rgb(0xbd, 0x93, 0xf9),
+        border_unfocused: Color::Rgb(0x65, 0x74, 0xa6),
+        focus_accent: Color::Rgb(0xbd, 0x93, 0xf9),
+        group_row: Color::Rgb(0xbf, 0xc3, 0xd9),
+        mode_normal_bg: Color::Rgb(0xbd, 0x93, 0xf9),
+        mode_normal_fg: Color::Rgb(0x28, 0x2a, 0x36),
+        mode_insert_bg: Color::Rgb(0xf1, 0xfa, 0x8c),
+        mode_insert_fg: Color::Rgb(0x28, 0x2a, 0x36),
+        error_text: Color::Rgb(0xff, 0x59, 0x59),
+    };
+
+    /// The default preset, retained as a named compatibility constant.
+    pub const DEFAULT: Palette = Self::DARK;
+
+    /// All preset names and their complete palettes.
+    pub fn presets() -> [(&'static str, Palette); 12] {
+        [
+            ("dark", Self::DARK),
+            ("light", Self::LIGHT),
+            ("ansi", Self::ANSI),
+            ("solarized-dark", Self::SOLARIZED_DARK),
+            ("solarized-light", Self::SOLARIZED_LIGHT),
+            ("catppuccin", Self::CATPPUCCIN),
+            ("github-dark", Self::GITHUB_DARK),
+            ("github-light", Self::GITHUB_LIGHT),
+            ("tokyo-night", Self::TOKYO_NIGHT),
+            ("gruvbox", Self::GRUVBOX),
+            ("nord", Self::NORD),
+            ("dracula", Self::DRACULA),
+        ]
+    }
+
+    /// Resolve a config name to a palette.
+    pub fn named(name: &str) -> Option<Palette> {
+        Self::presets()
+            .into_iter()
+            .find(|(n, _)| *n == name)
+            .map(|(_, p)| p)
+    }
+
+    /// Every role, including the backgrounds it is painted against.
+    pub fn roles(&self) -> [(&'static str, Color); 27] {
+        [
+            ("card.bg", self.card.bg),
+            ("card.fg", self.card.fg),
+            ("card.muted", self.card.muted),
+            ("card.dim", self.card.dim),
+            ("card.active", self.card.active),
+            ("card.idle", self.card.idle),
+            ("card.awaiting", self.card.awaiting),
+            ("card.error", self.card.error),
+            ("selection.bg", self.selection.bg),
+            ("selection.fg", self.selection.fg),
+            ("selection.muted", self.selection.muted),
+            ("selection.dim", self.selection.dim),
+            ("selection.active", self.selection.active),
+            ("selection.idle", self.selection.idle),
+            ("selection.awaiting", self.selection.awaiting),
+            ("selection.error", self.selection.error),
+            ("chrome_bg", self.chrome_bg),
+            ("sidebar_focus_bg", self.sidebar_focus_bg),
+            ("border_focused", self.border_focused),
+            ("border_unfocused", self.border_unfocused),
+            ("focus_accent", self.focus_accent),
+            ("group_row", self.group_row),
+            ("mode_normal_bg", self.mode_normal_bg),
+            ("mode_normal_fg", self.mode_normal_fg),
+            ("mode_insert_bg", self.mode_insert_bg),
+            ("mode_insert_fg", self.mode_insert_fg),
+            ("error_text", self.error_text),
+        ]
+    }
+
+    /// The surface a card sits on: the selection surface when it is the
+    /// highlighted card, the card surface otherwise.
+    pub fn surface(&self, selected: bool) -> &Surface {
+        if selected {
+            &self.selection
+        } else {
+            &self.card
+        }
+    }
+
+    /// Border style for a panel, by whether it holds focus.
+    pub fn border_style(&self, focused: bool) -> Style {
+        if focused {
+            Style::default().bg(self.chrome_bg).fg(self.border_focused)
+        } else {
+            Style::default()
+                .bg(self.chrome_bg)
+                .fg(self.border_unfocused)
+        }
+    }
+
+    /// Style for a sidebar group heading.
+    pub fn group_row_style(&self) -> Style {
+        Style::default()
+            .bg(self.chrome_bg)
+            .fg(self.group_row)
+            .add_modifier(Modifier::BOLD)
+    }
+
+    /// Style for the status bar's mode indicator.
+    pub fn mode_style(&self, insert: bool) -> Style {
+        if insert {
+            Style::default()
+                .fg(self.mode_insert_fg)
+                .bg(self.mode_insert_bg)
+        } else {
+            Style::default()
+                .fg(self.mode_normal_fg)
+                .bg(self.mode_normal_bg)
+        }
+    }
+
+    /// Style for error text outside a card.
+    pub fn error_style(&self) -> Style {
+        Style::default().bg(self.chrome_bg).fg(self.error_text)
+    }
+}
+
+impl Default for Palette {
+    fn default() -> Self {
+        Self::DEFAULT
+    }
+}
+
+fn active_slot() -> &'static std::sync::RwLock<Palette> {
+    static ACTIVE: std::sync::OnceLock<std::sync::RwLock<Palette>> = std::sync::OnceLock::new();
+    ACTIVE.get_or_init(|| std::sync::RwLock::new(Palette::DEFAULT))
+}
+
+/// Set the palette used by the running TUI.
+pub(crate) fn set_active(palette: Palette) {
+    *active_slot().write().expect("active palette lock poisoned") = palette;
+}
+
+/// The palette in force. Config-driven preset selection lands here at TUI
+/// startup, before the first frame is drawn.
+pub fn active() -> Palette {
+    *active_slot().read().expect("active palette lock poisoned")
+}
+
+/// WCAG relative luminance of an RGB role. Non-RGB colours have no fixed
+/// luminance — they are whatever the terminal theme says — so they return
+/// `None` and cannot be contrast-checked.
+pub fn relative_luminance(color: Color) -> Option<f64> {
+    let Color::Rgb(r, g, b) = color else {
+        return None;
+    };
+    fn channel(v: u8) -> f64 {
+        let v = v as f64 / 255.0;
+        if v <= 0.03928 {
+            v / 12.92
+        } else {
+            ((v + 0.055) / 1.055).powf(2.4)
+        }
+    }
+    Some(0.2126 * channel(r) + 0.7152 * channel(g) + 0.0722 * channel(b))
+}
+
+/// WCAG contrast ratio between two RGB roles, 1.0 (identical) to 21.0
+/// (black on white). `None` if either colour is not RGB.
+pub fn contrast_ratio(a: Color, b: Color) -> Option<f64> {
+    let (la, lb) = (relative_luminance(a)?, relative_luminance(b)?);
+    let (hi, lo) = if la >= lb { (la, lb) } else { (lb, la) };
+    Some((hi + 0.05) / (lo + 0.05))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    const STATES: [ActivityState; 4] = [
+        ActivityState::Active,
+        ActivityState::Idle,
+        ActivityState::AwaitingInput,
+        ActivityState::Error,
+    ];
+
+    /// Every preset except `ansi`, whose colours the terminal owns and which
+    /// therefore has no fixed luminance to assert against.
+    fn rgb_presets() -> impl Iterator<Item = (&'static str, Palette)> {
+        Palette::presets()
+            .into_iter()
+            .filter(|(_, p)| relative_luminance(p.card.bg).is_some())
+    }
+
+    /// Text roles clear WCAG AA (4.5:1) against their own surface; `dim` is
+    /// decoration and only has to clear the 3:1 non-text threshold.
+    #[test]
+    fn every_role_is_legible_on_its_own_surface() {
+        for (preset, p) in rgb_presets() {
+            for (surface_name, surface) in [("card", &p.card), ("selection", &p.selection)] {
+                for (role, color) in surface.roles() {
+                    let ratio = contrast_ratio(surface.bg, color)
+                        .unwrap_or_else(|| panic!("{preset}.{surface_name}.{role} must be RGB"));
+                    let floor = if role == "dim" { 3.0 } else { 4.5 };
+                    assert!(
+                        ratio >= floor,
+                        "{preset}.{surface_name}.{role} contrast {ratio:.2} is below {floor}"
+                    );
+                }
+            }
+        }
+    }
+
+    #[test]
+    fn every_preset_supplies_every_role() {
+        for (name, p) in Palette::presets() {
+            assert_eq!(p.roles().len(), 27, "{name} role set is incomplete");
+            assert_eq!(Palette::named(name), Some(p));
+        }
+        assert_eq!(Palette::named("unknown"), None);
+    }
+
+    /// The selection background exists to be seen as a different surface, not
+    /// merely a slightly different shade of the card.
+    #[test]
+    fn selection_background_is_distinguishable_from_the_card_background() {
+        for (name, p) in rgb_presets() {
+            let ratio = contrast_ratio(p.card.bg, p.selection.bg).unwrap();
+            assert!(
+                ratio >= 1.6,
+                "{name} card and selection backgrounds differ by only {ratio:.2}"
+            );
+        }
+    }
+
+    /// The bug this palette fixes: a state colour chosen for the dark card
+    /// background is not legible on the selection background, so the
+    /// selection surface carries its own — distinct — state colours.
+    #[test]
+    fn selection_state_colours_are_not_the_card_state_colours() {
+        for (name, p) in Palette::presets() {
+            for state in STATES {
+                assert_ne!(
+                    p.card.activity(state),
+                    p.selection.activity(state),
+                    "{name} {state:?} must have a selection-specific colour"
+                );
+            }
+        }
+    }
+
+    /// Other panels' roles are RGB too, so a preset swap moves all of them.
+    /// Foregrounds are checked against the chrome background they are
+    /// actually painted on; they must never rely on the terminal default.
+    #[test]
+    fn chrome_roles_are_rgb_values() {
+        for (preset, p) in rgb_presets() {
+            for (name, color) in p.roles().into_iter().skip(16) {
+                assert!(
+                    relative_luminance(color).is_some(),
+                    "{preset}.{name} must be an RGB value"
+                );
+            }
+            // The mode indicator paints fg on bg; both pairs must stay readable.
+            for (name, fg, bg) in [
+                ("normal", p.mode_normal_fg, p.mode_normal_bg),
+                ("insert", p.mode_insert_fg, p.mode_insert_bg),
+            ] {
+                let ratio = contrast_ratio(fg, bg).unwrap();
+                assert!(
+                    ratio >= 4.5,
+                    "{preset} mode {name} contrast {ratio:.2} is below 4.5"
+                );
+            }
+            for (name, fg, floor) in [
+                ("border_focused", p.border_focused, 3.0),
+                ("border_unfocused", p.border_unfocused, 3.0),
+                ("focus_accent", p.focus_accent, 3.0),
+                ("group_row", p.group_row, 4.5),
+                ("error_text", p.error_text, 4.5),
+            ] {
+                let ratio = contrast_ratio(fg, p.chrome_bg).unwrap();
+                assert!(
+                    ratio >= floor,
+                    "{preset}.{name} contrast {ratio:.2} is below {floor} on chrome_bg"
+                );
+            }
+            for (name, fg) in [
+                ("card.fg", p.card.fg),
+                ("card.muted", p.card.muted),
+                ("group_row", p.group_row),
+            ] {
+                let ratio = contrast_ratio(fg, p.sidebar_focus_bg).unwrap();
+                assert!(
+                    ratio >= 4.5,
+                    "{preset}.{name} contrast {ratio:.2} is below 4.5 on sidebar_focus_bg"
+                );
+            }
+        }
+    }
+
+    #[test]
+    fn contrast_ratio_matches_known_values() {
+        let black = Color::Rgb(0, 0, 0);
+        let white = Color::Rgb(255, 255, 255);
+        assert!((contrast_ratio(black, white).unwrap() - 21.0).abs() < 0.01);
+        assert!((contrast_ratio(white, white).unwrap() - 1.0).abs() < 0.01);
+        assert_eq!(contrast_ratio(Color::Cyan, white), None);
+    }
+}

crates/maestro-tui/src/pane.rs

@@ -74,7 +74,7 @@ impl Pane {
 
         // Place the terminal cursor at vt100's cursor position when we own
         // focus and the cursor is on-screen. Terminals blink it on their own.
-        if self.focused && !screen.hide_cursor() {
+        if self.focused && screen.scrollback() == 0 && !screen.hide_cursor() {
             let (cr, cc) = screen.cursor_position();
             if cr < rows && cc < cols {
                 f.set_cursor_position((area.x + cc, area.y + cr));
@@ -106,6 +106,9 @@ fn translate_cell_style(cell: &vt100::Cell) -> Style {
     s
 }
 
+/// PTY cell colours pass through verbatim: they belong to the program
+/// running in the pane, not to the TUI's own chrome, so they are deliberately
+/// not palette roles (see `crate::palette`).
 fn translate_color(c: vt100::Color) -> Option<Color> {
     match c {
         vt100::Color::Default => None,

crates/maestro-tui/src/render.rs

@@ -1,20 +1,20 @@
-//! Top-level draw orchestration. Composes sidebar / tab bar / pane / overlays
+//! Top-level draw orchestration. Composes sidebar / pane / overlays
 //! into one frame, and returns a [`RegionMap`] that the input router uses to
 //! hit-test mouse clicks.
 
 use ratatui::layout::{Constraint, Direction, Layout, Rect};
-use ratatui::style::{Color, Style};
+use ratatui::style::Modifier;
 use ratatui::text::Span;
-use ratatui::widgets::{Block, Borders, Paragraph};
+use ratatui::widgets::Paragraph;
 use ratatui::Frame;
 
 use crate::input::Region;
 use crate::keymap::Mode;
 use crate::overlays::{HelpOverlay, KillConfirm, Toast};
+use crate::palette;
 use crate::pane::Pane;
 use crate::sidebar::Sidebar;
-use crate::state::{AppState, Focus, OverlayKind};
+use crate::state::{AppState, Focus, OverlayKind, SidebarItem};
-use crate::tabs::TabBar;
 use crate::worktrees::{ReclaimConfirm, WorktreesView};
 
 /// Tagged regions for mouse hit-testing. The input router resolves a mouse
@@ -22,7 +22,7 @@ use crate::worktrees::{ReclaimConfirm, WorktreesView};
 #[derive(Debug, Default, Clone)]
 pub struct RegionMap {
     pub sidebar: Option<Rect>,
-    pub tab_bar: Option<Rect>,
+    pub sidebar_items: Vec<SidebarItem>,
     pub pane: Option<Rect>,
     pub modal: Option<Rect>,
 }
@@ -34,11 +34,6 @@ impl RegionMap {
                 return Region::Modal;
             }
         }
-        if let Some(r) = self.tab_bar {
-            if inside(r, col, row) {
-                return Region::Tab;
-            }
-        }
         if let Some(r) = self.sidebar {
             if inside(r, col, row) {
                 return Region::SidebarRow;
@@ -51,6 +46,24 @@ impl RegionMap {
         }
         Region::Unknown
     }
+
+    /// Resolve a mouse row against the rendered sidebar sequence. The title
+    /// occupies one inner row; groups occupy one row and visible cards two.
+    pub fn sidebar_item_at(&self, row: u16) -> Option<SidebarItem> {
+        let area = self.sidebar?;
+        let mut cursor = area.y.saturating_add(1);
+        for item in &self.sidebar_items {
+            let height = match item {
+                SidebarItem::Group(_) => 1,
+                SidebarItem::Session(_) => 2,
+            };
+            if row >= cursor && row < cursor.saturating_add(height) {
+                return Some(item.clone());
+            }
+            cursor = cursor.saturating_add(height);
+        }
+        None
+    }
 }
 
 fn inside(r: Rect, col: u16, row: u16) -> bool {
@@ -62,9 +75,10 @@ fn inside(r: Rect, col: u16, row: u16) -> bool {
 #[derive(Debug)]
 pub struct RenderInputs<'a> {
     pub sidebar: &'a Sidebar,
-    pub tab_bar: &'a TabBar,
+    pub home_dir: &'a str,
+    pub pane_title: &'a str,
     pub pane: Option<&'a Pane>,
-    /// Inline spawn form when the active tab's pane is a draft (issue #63).
+    /// Inline spawn form when the pane is a draft (issue #63).
     pub draft: Option<&'a crate::draft::DraftPane>,
     pub state: &'a AppState,
     pub help: &'a HelpOverlay,
@@ -101,43 +115,36 @@ pub fn draw(f: &mut Frame, inputs: RenderInputs<'_>) -> RegionMap {
     let right = cols[1];
 
     if inputs.state.sidebar_visible {
-        inputs
+        inputs.sidebar.render_with_focus_and_collapsed_home(
-            .sidebar
+            f,
-            .render_with_focus(f, sidebar_area, inputs.state.focus == Focus::Sidebar);
+            sidebar_area,
+            inputs.state.focus == Focus::Sidebar,
+            &inputs.state.collapsed_sidebar_groups,
+            inputs.home_dir,
+        );
         map.sidebar = Some(sidebar_area);
+        map.sidebar_items = inputs
+            .sidebar
+            .rendered_items_with_collapsed(&inputs.state.collapsed_sidebar_groups);
     }
 
-    // 1-row tab bar + 1-row horizontal rule (doubles as the pane's focus
-    // indicator) + flex pane area below. Saves the 4 rows the old
-    // `Length(3) + Borders::ALL` layout was eating before any content showed.
     let rows = Layout::default()
         .direction(Direction::Vertical)
-        .constraints([
+        .constraints([Constraint::Length(1), Constraint::Min(0)])
-            Constraint::Length(1),
-            Constraint::Length(1),
-            Constraint::Min(0),
-        ])
         .split(right);
-    let tab_area = rows[0];
+    let title_area = rows[0];
-    let separator_area = rows[1];
+    let pane_area = rows[1];
-    let pane_area = rows[2];
-
-    inputs.tab_bar.render(f, tab_area);
-    map.tab_bar = Some(tab_area);
 
     let pane_focused = inputs.state.focus == Focus::Pane;
-    f.render_widget(
+    render_title_bar(f, title_area, inputs.pane_title, pane_focused);
-        Block::default()
-            .borders(Borders::TOP)
-            .border_style(focus_style(pane_focused)),
-        separator_area,
-    );
     if let Some(p) = inputs.pane {
         p.render(f, pane_area);
     }
     if let Some(d) = inputs.draft {
         d.render(f, pane_area, pane_focused);
     }
+    // `RegionMap::pane` is also the PTY resize source. The title bar is
+    // chrome; every remaining cell belongs to the emulator.
     map.pane = Some(pane_area);
 
     // Status bar — always visible, never eclipsed by overlays so the user can
@@ -193,14 +200,15 @@ pub fn draw(f: &mut Frame, inputs: RenderInputs<'_>) -> RegionMap {
     map
 }
 
-/// Border style for a panel based on whether it currently has focus.
+fn render_title_bar(f: &mut Frame, area: Rect, title: &str, focused: bool) {
-/// Focused = cyan; unfocused = the terminal default.
+    let palette = palette::active();
-fn focus_style(focused: bool) -> Style {
+    let style = if focused {
-    if focused {
+        palette.mode_style(false)
-        Style::default().fg(Color::Cyan)
     } else {
-        Style::default()
+        palette.card.text_style()
     }
+    .add_modifier(Modifier::BOLD);
+    f.render_widget(Paragraph::new(format!(" {title}")).style(style), area);
 }
 
 /// Render the always-visible status bar at the bottom of the frame. Surfaces
@@ -217,12 +225,9 @@ fn render_status_bar(f: &mut Frame, area: Rect, state: &AppState) {
     };
     let hint = match state.mode {
         Mode::Normal => "j/k: nav  •  enter: attach  •  s: new draft  •  ?: help  •  ^Wq: quit",
-        Mode::Insert => "^a: back to normal",
+        Mode::Insert => "^a: return to sidebar",
-    };
-    let mode_style = match state.mode {
-        Mode::Normal => Style::default().fg(Color::Black).bg(Color::Cyan),
-        Mode::Insert => Style::default().fg(Color::Black).bg(Color::Yellow),
     };
+    let mode_style = palette::active().mode_style(state.mode == Mode::Insert);
     let line = ratatui::text::Line::from(vec![
         Span::styled(format!(" {mode_label} "), mode_style),
         Span::raw(format!("  {focus_label}  •  {hint}")),
@@ -244,22 +249,16 @@ mod tests {
                 width: 10,
                 height: 20,
             }),
-            tab_bar: Some(Rect {
+            sidebar_items: Vec::new(),
+            pane: Some(Rect {
                 x: 10,
                 y: 0,
                 width: 30,
-                height: 3,
+                height: 20,
-            }),
-            pane: Some(Rect {
-                x: 10,
-                y: 3,
-                width: 30,
-                height: 17,
             }),
             modal: None,
         };
         assert_eq!(map.region_at(5, 5), Region::SidebarRow);
-        assert_eq!(map.region_at(15, 1), Region::Tab);
         assert_eq!(map.region_at(15, 5), Region::Pane);
         assert_eq!(map.region_at(50, 50), Region::Unknown);
     }
@@ -273,17 +272,12 @@ mod tests {
                 width: 10,
                 height: 20,
             }),
-            tab_bar: Some(Rect {
+            sidebar_items: Vec::new(),
+            pane: Some(Rect {
                 x: 10,
                 y: 0,
                 width: 30,
-                height: 3,
+                height: 20,
-            }),
-            pane: Some(Rect {
-                x: 10,
-                y: 3,
-                width: 30,
-                height: 17,
             }),
             modal: Some(Rect {
                 x: 5,
@@ -297,6 +291,40 @@ mod tests {
         assert_eq!(map.region_at(3, 12), Region::SidebarRow); // outside modal
     }
 
+    #[test]
+    fn sidebar_mouse_rows_follow_group_and_two_line_card_heights() {
+        use std::path::PathBuf;
+        use uuid::Uuid;
+
+        let group_a = SidebarItem::Group(PathBuf::from("/a"));
+        let card_a = SidebarItem::Session(Uuid::from_u128(1));
+        let group_b = SidebarItem::Group(PathBuf::from("/b"));
+        let card_b = SidebarItem::Session(Uuid::from_u128(2));
+        let map = RegionMap {
+            sidebar: Some(Rect::new(0, 0, 28, 10)),
+            sidebar_items: vec![group_a.clone(), card_a.clone(), group_b.clone(), card_b],
+            ..RegionMap::default()
+        };
+        assert_eq!(map.sidebar_item_at(1), Some(group_a));
+        assert_eq!(map.sidebar_item_at(2), Some(card_a.clone()));
+        assert_eq!(map.sidebar_item_at(3), Some(card_a));
+        assert_eq!(map.sidebar_item_at(4), Some(group_b));
+
+        let collapsed = RegionMap {
+            sidebar: Some(Rect::new(0, 0, 28, 10)),
+            sidebar_items: vec![
+                SidebarItem::Group(PathBuf::from("/a")),
+                SidebarItem::Group(PathBuf::from("/b")),
+                SidebarItem::Session(Uuid::from_u128(2)),
+            ],
+            ..RegionMap::default()
+        };
+        assert_eq!(
+            collapsed.sidebar_item_at(2),
+            Some(SidebarItem::Group(PathBuf::from("/b")))
+        );
+    }
+
     /// Issue #63: an empty pane is a draft — the frame must show the spawn
     /// form where the terminal would otherwise be.
     #[test]
@@ -316,14 +344,11 @@ mod tests {
             highlight: None,
             attached: HashSet::new(),
         };
-        let tab_bar = TabBar {
-            tab_names: vec!["1".into()],
-            active_idx: 0,
-        };
         let help = HelpOverlay { lines: Vec::new() };
         let inputs = RenderInputs {
             sidebar: &sidebar,
-            tab_bar: &tab_bar,
+            home_dir: "",
+            pane_title: "new session",
             pane: None,
             draft: Some(draft),
             state: &state,
@@ -347,7 +372,7 @@ mod tests {
             out.push('\n');
         }
         for s in [
-            "draft",
+            "new session",
             "cmd:",
             "dir:",
             "name:",
@@ -357,4 +382,89 @@ mod tests {
             assert!(out.contains(s), "missing {s:?}:\n{out}");
         }
     }
+
+    #[test]
+    fn panel_rectangles_are_stable_when_focus_moves() {
+        use crate::overlays::HelpOverlay;
+        use crate::sidebar::Sidebar;
+        use std::collections::HashSet;
+
+        let sidebar = Sidebar {
+            sessions: Vec::new(),
+            highlight: None,
+            attached: HashSet::new(),
+        };
+        let help = HelpOverlay { lines: Vec::new() };
+        let draw_map = |focus| {
+            let mut state = AppState::new();
+            state.focus = focus;
+            let inputs = RenderInputs {
+                sidebar: &sidebar,
+                home_dir: "",
+                pane_title: "session",
+                pane: None,
+                draft: None,
+                state: &state,
+                help: &help,
+                worktrees: None,
+            };
+            let backend = ratatui::backend::TestBackend::new(80, 24);
+            let mut terminal = ratatui::Terminal::new(backend).unwrap();
+            let mut map = None;
+            terminal.draw(|f| map = Some(draw(f, inputs))).unwrap();
+            map.unwrap()
+        };
+
+        let sidebar_focus = draw_map(Focus::Sidebar);
+        let pane_focus = draw_map(Focus::Pane);
+        assert_eq!(sidebar_focus.sidebar, pane_focus.sidebar);
+        assert_eq!(sidebar_focus.pane, pane_focus.pane);
+        assert_eq!(sidebar_focus.pane, Some(Rect::new(28, 1, 52, 22)));
+    }
+
+    #[test]
+    fn panel_focus_uses_backgrounds_without_borders() {
+        use crate::overlays::HelpOverlay;
+        use crate::sidebar::Sidebar;
+        use std::collections::HashSet;
+
+        let sidebar = Sidebar {
+            sessions: Vec::new(),
+            highlight: None,
+            attached: HashSet::new(),
+        };
+        let help = HelpOverlay { lines: Vec::new() };
+        let render = |focus| {
+            let mut state = AppState::new();
+            state.focus = focus;
+            let inputs = RenderInputs {
+                sidebar: &sidebar,
+                home_dir: "",
+                pane_title: "session",
+                pane: None,
+                draft: None,
+                state: &state,
+                help: &help,
+                worktrees: None,
+            };
+            let backend = ratatui::backend::TestBackend::new(80, 24);
+            let mut terminal = ratatui::Terminal::new(backend).unwrap();
+            terminal
+                .draw(|f| {
+                    draw(f, inputs);
+                })
+                .unwrap();
+            terminal.backend().buffer().clone()
+        };
+
+        let sidebar_focused = render(Focus::Sidebar);
+        let pane_focused = render(Focus::Pane);
+        let p = palette::active();
+        assert_eq!(sidebar_focused[(0, 0)].style().bg, Some(p.sidebar_focus_bg));
+        assert_eq!(pane_focused[(0, 0)].style().bg, Some(p.chrome_bg));
+        assert_eq!(sidebar_focused[(28, 0)].style().bg, Some(p.card.bg));
+        assert_eq!(pane_focused[(28, 0)].style().bg, Some(p.mode_normal_bg));
+        let title: String = (28..80).map(|x| pane_focused[(x, 0)].symbol()).collect();
+        assert!(title.contains("session"), "missing title: {title:?}");
+    }
 }

crates/maestro-tui/src/session_task.rs

@@ -23,6 +23,10 @@ use maestro_protocol::ClientControl;
 use tokio::sync::mpsc;
 use tokio_tungstenite::tungstenite::Message;
 
+/// Match the browser terminal's retained history without letting long-running
+/// sessions grow the client without bound.
+pub const SCROLLBACK_ROWS: usize = 5_000;
+
 /// Input the dispatcher (or the resize tracker) pushes to a session task.
 #[derive(Debug, Clone)]
 pub enum SessionInput {
@@ -103,7 +107,7 @@ impl SessionTask {
     /// up with `SessionInput::Resize` on every frame whose allocation changes.
     pub fn spawn(ws_url: String, rows: u16, cols: u16) -> SessionHandle {
         let (tx, mut rx) = mpsc::channel::<SessionInput>(64);
-        let parser = Arc::new(Mutex::new(vt100::Parser::new(rows, cols, 0)));
+        let parser = Arc::new(Mutex::new(vt100::Parser::new(rows, cols, SCROLLBACK_ROWS)));
         let state = Arc::new(AtomicU8::new(SessionState::Connecting as u8));
 
         let parser_bg = parser.clone();

crates/maestro-tui/src/state.rs

@@ -1,13 +1,15 @@
 //! `AppState` — the top-level mutable state of the running TUI.
 //!
-//! v1 keeps it small on purpose: a list of tabs (each bound to at most one
+//! v1 keeps it small on purpose: one pane containing a session or draft form,
-//! session or a draft form), an active tab index, focus split between sidebar
+//! focus split between sidebar and pane, the current input mode, and an optional overlay (kill confirm,
-//! and pane, the current input mode, and an optional overlay (kill confirm,
 //! help, transient toast). The spawn form is no longer an overlay — an empty
 //! pane is a draft pane (issue #63).
 //!
 //! v1.5 will replace `Tab::pane`'s single slot with a split tree.
 
+use std::collections::HashSet;
+use std::path::PathBuf;
+
 use uuid::Uuid;
 
 use crate::draft::DraftPane;
@@ -19,8 +21,18 @@ pub enum Focus {
     Pane,
 }
 
+/// One selectable item in the rendered sidebar sequence.
+///
+/// Group paths, unlike a session's position in the catalog, survive catalog
+/// redraws and make a highlighted collapsed group unambiguous.
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub enum SidebarItem {
+    Group(PathBuf),
+    Session(Uuid),
+}
+
 /// What a tab's pane slot holds: a live session, or an inline draft form.
-// The draft variant dwarfs `Session(Uuid)`; tabs are moved rarely enough
+// The draft variant dwarfs `Session(Uuid)`; the pane is moved rarely enough
 // that boxing every access costs more than the copy does.
 #[allow(clippy::large_enum_variant)]
 #[derive(Debug, Clone, PartialEq)]
@@ -70,7 +82,10 @@ pub struct AppState {
     pub focus: Focus,
     pub mode: Mode,
     pub sidebar_visible: bool,
-    pub sidebar_highlight: Option<Uuid>,
+    pub sidebar_highlight: Option<SidebarItem>,
+    /// Group paths whose cards are hidden. This is UI state rather than
+    /// catalog state, so it survives every catalog redraw.
+    pub collapsed_sidebar_groups: HashSet<PathBuf>,
     /// Private: every transition goes through [`AppState::show_overlay`],
     /// [`AppState::dismiss_overlay`] or [`AppState::toast`]. Poking the field
     /// from four call sites is what left a toast on screen with no way to
@@ -96,6 +111,7 @@ impl AppState {
             mode: Mode::Normal,
             sidebar_visible: true,
             sidebar_highlight: None,
+            collapsed_sidebar_groups: HashSet::new(),
             overlay: None,
         }
     }
@@ -126,57 +142,6 @@ impl AppState {
         &mut self.tabs[self.active_tab_idx]
     }
 
-    /// Append a new tab and switch to it. Sidebar regains focus so the user
-    /// can pick something to attach.
-    pub fn new_tab(&mut self) {
-        let name = format!("{}", self.tabs.len() + 1);
-        self.tabs.push(Tab { name, pane: None });
-        self.active_tab_idx = self.tabs.len() - 1;
-        self.focus = Focus::Sidebar;
-    }
-
-    /// Drop the active tab. No-op if it's the only one — there must always
-    /// be at least one tab.
-    ///
-    /// Returns the session that tab was showing, if any, so the caller can
-    /// release its emulator. Without that the tab's WebSocket task and vt100
-    /// parser outlive the tab forever. A draft pane holds no session and
-    /// releases nothing.
-    pub fn close_tab(&mut self) -> Option<Uuid> {
-        if self.tabs.len() <= 1 {
-            return None;
-        }
-        let closed = self.tabs.remove(self.active_tab_idx);
-        if self.active_tab_idx >= self.tabs.len() {
-            self.active_tab_idx = self.tabs.len() - 1;
-        }
-        let sid = closed.session()?;
-        // Only release it if no other tab still shows the same session.
-        let still_shown = self.tabs.iter().any(|t| t.session() == Some(sid));
-        (!still_shown).then_some(sid)
-    }
-
-    pub fn next_tab(&mut self) {
-        if self.tabs.is_empty() {
-            return;
-        }
-        self.active_tab_idx = (self.active_tab_idx + 1) % self.tabs.len();
-    }
-
-    pub fn prev_tab(&mut self) {
-        if self.tabs.is_empty() {
-            return;
-        }
-        self.active_tab_idx = (self.active_tab_idx + self.tabs.len() - 1) % self.tabs.len();
-    }
-
-    pub fn goto_tab(&mut self, n: u8) {
-        let idx = (n as usize)
-            .saturating_sub(1)
-            .min(self.tabs.len().saturating_sub(1));
-        self.active_tab_idx = idx;
-    }
-
     /// Bind a session to the active tab, move focus into the pane, and
     /// drop straight into Insert mode so keystrokes go to the session
     /// without an extra `i` press. The leader returns to Normal.
@@ -186,14 +151,10 @@ impl AppState {
         self.mode = Mode::Insert;
     }
 
-    /// Open a draft form in a pane (issue #63): reuse the empty active pane,
+    /// Replace the pane with a draft form. Focus lands in the pane, Insert
-    /// otherwise open a fresh tab for it — v1 has no split tree, so "split"
+    /// mode on, so typing starts immediately, same flow as
-    /// means a new tab. Focus lands in the pane, Insert mode on, so typing
+    /// [`Self::attach_to_focused`].
-    /// starts immediately, same flow as [`Self::attach_to_focused`].
     pub fn open_draft_pane(&mut self) {
-        if self.active_tab().pane.is_some() {
-            self.new_tab();
-        }
         self.active_tab_mut().pane = Some(PaneRef::Draft(DraftPane::default()));
         self.focus = Focus::Pane;
         self.mode = Mode::Insert;
@@ -213,19 +174,32 @@ impl AppState {
     }
 
     /// Move the sidebar highlight by `delta` (positive = down) within the
-    /// given ordered list of selectable session ids. Wraps. No-op on empty.
+    /// rendered item sequence. Wraps. No-op on empty.
-    pub fn move_sidebar_highlight(&mut self, order: &[Uuid], delta: i32) {
+    pub fn move_sidebar_highlight(&mut self, order: &[SidebarItem], delta: i32) {
         if order.is_empty() {
             return;
         }
         let len = order.len() as i32;
         let cur = self
             .sidebar_highlight
-            .and_then(|id| order.iter().position(|x| *x == id))
+            .as_ref()
+            .and_then(|id| order.iter().position(|x| x == id))
             .map(|i| i as i32)
             .unwrap_or(-1);
         let next = (cur + delta).rem_euclid(len) as usize;
-        self.sidebar_highlight = Some(order[next]);
+        self.sidebar_highlight = Some(order[next].clone());
+    }
+
+    /// Toggle a group. When collapsing a group containing the current card,
+    /// leave the highlight on the group row that remains visible.
+    pub fn toggle_sidebar_group(&mut self, key: PathBuf, contains_highlight: bool) {
+        if self.collapsed_sidebar_groups.remove(&key) {
+            return;
+        }
+        self.collapsed_sidebar_groups.insert(key.clone());
+        if contains_highlight {
+            self.sidebar_highlight = Some(SidebarItem::Group(key));
+        }
     }
 
     /// Toggle sidebar visibility.
@@ -252,88 +226,36 @@ mod tests {
         assert!(state.overlay.is_none());
     }
 
-    #[test]
-    fn new_tab_extends_and_focuses() {
-        let mut state = AppState::new();
-        state.new_tab();
-        assert_eq!(state.tabs.len(), 2);
-        assert_eq!(state.active_tab_idx, 1);
-        assert_eq!(state.focus, Focus::Sidebar);
-    }
-
-    #[test]
-    fn close_tab_keeps_at_least_one() {
-        let mut state = AppState::new();
-        state.close_tab();
-        assert_eq!(state.tabs.len(), 1);
-        state.new_tab();
-        state.close_tab();
-        assert_eq!(state.tabs.len(), 1);
-    }
-
-    #[test]
-    fn close_tab_advances_when_last_is_closed() {
-        let mut state = AppState::new();
-        state.new_tab();
-        state.new_tab();
-        assert_eq!(state.active_tab_idx, 2);
-        state.close_tab();
-        assert_eq!(state.tabs.len(), 2);
-        assert_eq!(state.active_tab_idx, 1);
-    }
-
-    #[test]
-    fn next_prev_tab_wraps() {
-        let mut state = AppState::new();
-        state.new_tab();
-        state.new_tab();
-        state.active_tab_idx = 0;
-        state.next_tab();
-        assert_eq!(state.active_tab_idx, 1);
-        state.next_tab();
-        assert_eq!(state.active_tab_idx, 2);
-        state.next_tab();
-        assert_eq!(state.active_tab_idx, 0);
-        state.prev_tab();
-        assert_eq!(state.active_tab_idx, 2);
-    }
-
-    #[test]
-    fn goto_tab_uses_one_based_clamp() {
-        let mut state = AppState::new();
-        state.new_tab();
-        state.new_tab();
-        state.goto_tab(1);
-        assert_eq!(state.active_tab_idx, 0);
-        state.goto_tab(2);
-        assert_eq!(state.active_tab_idx, 1);
-        state.goto_tab(99);
-        // Clamped to last available tab.
-        assert_eq!(state.active_tab_idx, state.tabs.len() - 1);
-    }
-
     #[test]
     fn move_sidebar_highlight_walks_order_and_wraps() {
         let mut state = AppState::new();
         let a = Uuid::from_u128(1);
         let b = Uuid::from_u128(2);
         let c = Uuid::from_u128(3);
-        let order = vec![a, b, c];
+        let order = vec![
+            SidebarItem::Session(a),
+            SidebarItem::Group("repo".into()),
+            SidebarItem::Session(b),
+            SidebarItem::Session(c),
+        ];
 
         // No prior highlight + delta +1 lands on first item.
         state.move_sidebar_highlight(&order, 1);
-        assert_eq!(state.sidebar_highlight, Some(a));
+        assert_eq!(state.sidebar_highlight, Some(SidebarItem::Session(a)));
 
         state.move_sidebar_highlight(&order, 1);
-        assert_eq!(state.sidebar_highlight, Some(b));
+        assert_eq!(
+            state.sidebar_highlight,
+            Some(SidebarItem::Group("repo".into()))
+        );
         state.move_sidebar_highlight(&order, 1);
-        assert_eq!(state.sidebar_highlight, Some(c));
+        assert_eq!(state.sidebar_highlight, Some(SidebarItem::Session(b)));
         // Wraps forward.
         state.move_sidebar_highlight(&order, 1);
-        assert_eq!(state.sidebar_highlight, Some(a));
+        assert_eq!(state.sidebar_highlight, Some(SidebarItem::Session(c)));
         // Wraps backward.
         state.move_sidebar_highlight(&order, -1);
-        assert_eq!(state.sidebar_highlight, Some(c));
+        assert_eq!(state.sidebar_highlight, Some(SidebarItem::Session(b)));
     }
 
     #[test]
@@ -343,6 +265,22 @@ mod tests {
         assert_eq!(state.sidebar_highlight, None);
     }
 
+    #[test]
+    fn collapsing_highlighted_group_moves_a_card_highlight_to_the_group() {
+        let key = PathBuf::from("/repo");
+        let mut state = AppState::new();
+        state.sidebar_highlight = Some(SidebarItem::Session(Uuid::from_u128(9)));
+        state.toggle_sidebar_group(key.clone(), true);
+        assert_eq!(
+            state.sidebar_highlight,
+            Some(SidebarItem::Group(key.clone()))
+        );
+        assert!(state.collapsed_sidebar_groups.contains(&key));
+        state.toggle_sidebar_group(key.clone(), false);
+        assert!(!state.collapsed_sidebar_groups.contains(&key));
+        assert_eq!(state.sidebar_highlight, Some(SidebarItem::Group(key)));
+    }
+
     #[test]
     fn attach_binds_focuses_pane_and_enters_insert_mode() {
         let mut state = AppState::new();
@@ -367,38 +305,6 @@ mod tests {
         assert_eq!(state.focus, Focus::Pane);
     }
 
-    /// The emulator leak: a closed tab's session must come back so the caller
-    /// can abort its WebSocket task.
-    #[test]
-    fn close_tab_reports_the_session_it_dropped() {
-        let mut state = AppState::new();
-        let sid = Uuid::from_u128(3);
-        state.new_tab();
-        state.active_tab_mut().pane = Some(PaneRef::Session(sid));
-
-        assert_eq!(state.close_tab(), Some(sid));
-    }
-
-    /// ...but not while another tab still shows it.
-    #[test]
-    fn close_tab_keeps_a_session_another_tab_still_shows() {
-        let mut state = AppState::new();
-        let sid = Uuid::from_u128(4);
-        state.active_tab_mut().pane = Some(PaneRef::Session(sid));
-        state.new_tab();
-        state.active_tab_mut().pane = Some(PaneRef::Session(sid));
-
-        assert_eq!(state.close_tab(), None);
-    }
-
-    #[test]
-    fn close_tab_is_a_no_op_on_the_last_tab() {
-        let mut state = AppState::new();
-        state.active_tab_mut().pane = Some(PaneRef::Session(Uuid::from_u128(5)));
-        assert_eq!(state.close_tab(), None);
-        assert_eq!(state.tabs.len(), 1);
-    }
-
     #[test]
     fn dismiss_overlay_reports_whether_one_was_showing() {
         let mut state = AppState::new();
@@ -420,18 +326,14 @@ mod tests {
         assert_eq!(state.tabs.len(), 1);
     }
 
-    /// A tab already showing a session gets a fresh tab for the draft; v1
-    /// has no split tree, so a new tab is the "split".
     #[test]
-    fn open_draft_over_a_session_opens_a_new_tab() {
+    fn open_draft_over_a_session_reuses_the_pane() {
         let mut state = AppState::new();
         state.attach_to_focused(Uuid::from_u128(9));
         state.open_draft_pane();
-        assert_eq!(state.tabs.len(), 2);
+        assert_eq!(state.tabs.len(), 1);
-        assert_eq!(state.active_tab_idx, 1);
+        assert_eq!(state.active_tab_idx, 0);
         assert!(matches!(state.active_tab().pane, Some(PaneRef::Draft(_))));
-        // The session tab is untouched.
-        assert_eq!(state.tabs[0].session(), Some(Uuid::from_u128(9)));
     }
 
     /// Web parity (#57): submitting fills the pane in place.
@@ -445,14 +347,4 @@ mod tests {
         assert_eq!(state.focus, Focus::Pane);
         assert_eq!(state.mode, Mode::Insert);
     }
-
-    /// A closed draft tab holds no session, so nothing is released.
-    #[test]
-    fn close_tab_reports_nothing_for_a_draft_pane() {
-        let mut state = AppState::new();
-        state.open_draft_pane();
-        state.new_tab();
-        state.active_tab_idx = 0;
-        assert_eq!(state.close_tab(), None);
-    }
 }

crates/maestro-tui/src/tabs.rs

@@ -1,61 +0,0 @@
-//! Tab-bar widget — top row of the main area.
-
-use ratatui::layout::Rect;
-use ratatui::style::{Modifier, Style};
-use ratatui::text::Line;
-use ratatui::widgets::Tabs;
-use ratatui::Frame;
-
-#[derive(Debug, Clone)]
-pub struct TabBar {
-    pub tab_names: Vec<String>,
-    pub active_idx: usize,
-}
-
-impl TabBar {
-    pub fn render(&self, f: &mut Frame, area: Rect) {
-        let titles: Vec<Line> = self
-            .tab_names
-            .iter()
-            .map(|n| Line::from(n.as_str()))
-            .collect();
-        let tabs = Tabs::new(titles)
-            .select(self.active_idx)
-            .highlight_style(Style::default().add_modifier(Modifier::REVERSED));
-        f.render_widget(tabs, area);
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use ratatui::backend::TestBackend;
-    use ratatui::Terminal;
-
-    fn render_to_string(bar: &TabBar, w: u16, h: u16) -> String {
-        let backend = TestBackend::new(w, h);
-        let mut terminal = Terminal::new(backend).unwrap();
-        terminal.draw(|f| bar.render(f, f.area())).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
-    }
-
-    #[test]
-    fn renders_three_tab_names() {
-        let bar = TabBar {
-            tab_names: vec!["1".into(), "2".into(), "3".into()],
-            active_idx: 1,
-        };
-        let rendered = render_to_string(&bar, 40, 1);
-        assert!(rendered.contains("1"));
-        assert!(rendered.contains("2"));
-        assert!(rendered.contains("3"));
-    }
-}

crates/maestro/src/main.rs

@@ -19,8 +19,7 @@ use tracing_subscriber::EnvFilter;
 #[command(
     name = "maestro",
     version,
-    about = "Unified CLI / daemon / TUI for the Maestro terminal-session orchestrator",
+    about = "Unified CLI / daemon / TUI for the Maestro terminal-session orchestrator"
-    arg_required_else_help = true
 )]
 struct Cli {
     /// Override the daemon HTTP base clients talk to (e.g.
@@ -37,8 +36,11 @@ struct Cli {
     #[arg(short, long, global = true, action = clap::ArgAction::Count)]
     verbose: u8,
 
+    /// A missing subcommand defaults to the TUI (#119): a bare `maestro` opens
+    /// the terminal UI. Builds without the `tui` feature have no UI surface,
+    /// so they print help and exit 0 instead.
     #[command(subcommand)]
-    command: Command,
+    command: Option<Command>,
 }
 
 #[derive(Debug, Subcommand)]
@@ -55,6 +57,9 @@ enum Command {
     /// Kill a session by ID.
     #[cfg(feature = "cli")]
     Kill(maestro_cli::cli::KillArgs),
+    /// Install or update the agent activity hook (#106).
+    #[cfg(feature = "cli")]
+    Hooks(maestro_cli::cli::HooksArgs),
     /// Per-host daemon: tmux wrapper + session API.
     #[cfg(feature = "daemon")]
     Daemon {
@@ -86,7 +91,22 @@ fn main() -> ExitCode {
 }
 
 async fn dispatch(cli: Cli) -> Result<(), Box<dyn std::error::Error>> {
-    match cli.command {
+    let command = match cli.command {
+        Some(command) => command,
+        None => {
+            #[cfg(feature = "tui")]
+            {
+                Command::Tui(maestro_tui::cli::TuiArgs { daemon_url: None })
+            }
+            #[cfg(not(feature = "tui"))]
+            {
+                use clap::CommandFactory;
+                let _ = <Cli as CommandFactory>::command().print_help();
+                return Ok(());
+            }
+        }
+    };
+    match command {
         #[cfg(feature = "cli")]
         Command::List(args) => {
             maestro_cli::dispatch(
@@ -123,6 +143,15 @@ async fn dispatch(cli: Cli) -> Result<(), Box<dyn std::error::Error>> {
             )
             .await?
         }
+        #[cfg(feature = "cli")]
+        Command::Hooks(args) => {
+            maestro_cli::dispatch(
+                maestro_cli::cli::Command::Hooks(args),
+                cli.config,
+                cli.daemon_url,
+            )
+            .await?
+        }
         #[cfg(feature = "daemon")]
         Command::Daemon { cmd } => maestro_daemon::cli::dispatch(cli.config, cmd).await?,
         #[cfg(feature = "tui")]
@@ -154,15 +183,19 @@ fn init_tracing(cli: &Cli) {
 }
 
 #[cfg(feature = "cli")]
-fn is_cli_subcommand(command: &Command) -> bool {
+fn is_cli_subcommand(command: &Option<Command>) -> bool {
     matches!(
         command,
-        Command::List(_) | Command::Spawn(_) | Command::Attach(_) | Command::Kill(_)
+        Some(Command::List(_))
+            | Some(Command::Spawn(_))
+            | Some(Command::Attach(_))
+            | Some(Command::Kill(_))
+            | Some(Command::Hooks(_))
     )
 }
 
 #[cfg(not(feature = "cli"))]
-fn is_cli_subcommand(_command: &Command) -> bool {
+fn is_cli_subcommand(_command: &Option<Command>) -> bool {
     false
 }
 
@@ -200,12 +233,20 @@ mod tests {
     }
 
     /// Parse argv the way `main` does, returning just the dispatched subcommand.
-    fn command_of(argv: &[&str]) -> Command {
+    fn command_of(argv: &[&str]) -> Option<Command> {
         Cli::try_parse_from(argv)
             .unwrap_or_else(|e| panic!("parse {argv:?}: {e}"))
             .command
     }
 
+    #[test]
+    fn bare_invocation_parses_to_no_subcommand() {
+        // The TUI-vs-help default is applied in `dispatch`; parsing must not
+        // reject an empty argv.
+        assert!(command_of(&["maestro"]).is_none());
+        assert!(command_of(&["maestro", "--verbose"]).is_none());
+    }
+
     #[cfg(feature = "cli")]
     #[test]
     fn cli_subcommands_are_classified_as_cli() {

crates/maestro/tests/cli.rs

@@ -54,11 +54,35 @@ fn version_flag_succeeds() {
     assert!(text.contains("maestro"), "--version output: {text}");
 }
 
+/// A bare `maestro` must never fall back to help on a build that has a TUI:
+/// the missing subcommand defaults to `tui` (#119). Point at a port with
+/// nothing listening so the TUI's health probe fails fast instead of blocking
+/// on a terminal.
+#[cfg(feature = "tui")]
 #[test]
-fn no_args_prints_help_and_fails() {
+fn bare_invocation_dispatches_to_the_tui() {
-    // `arg_required_else_help = true` => exit non-zero but show usage.
+    let (ok, text) = run(&["--daemon-url", "http://127.0.0.1:9"]);
+    assert!(
+        !ok,
+        "TUI against a dead daemon should exit non-zero:\n{text}"
+    );
+    assert!(
+        text.contains("daemon unreachable"),
+        "bare invocation should have run the TUI's daemon probe:\n{text}"
+    );
+    assert!(
+        !text.contains("Usage"),
+        "bare invocation must not print help when a TUI exists:\n{text}"
+    );
+}
+
+/// Builds without the `tui` feature keep the historical behaviour: no args =>
+/// help, exit 0 (#119).
+#[cfg(not(feature = "tui"))]
+#[test]
+fn bare_invocation_prints_help_and_exits_zero() {
     let (ok, text) = run(&[]);
-    assert!(!ok, "bare invocation should fail:\n{text}");
+    assert!(ok, "bare invocation should exit 0:\n{text}");
     assert!(text.contains("Usage"), "expected usage text:\n{text}");
 }
 

docs/INSTALL.md

@@ -119,6 +119,9 @@ The wizard always installs the default-feature build.
 
 `maestro tui` is the keyboard-and-mouse driven terminal UI client. It ships
 in the default feature set, so a vanilla `cargo install maestro` builds it.
+A bare `maestro` opens the TUI too — the missing subcommand defaults to `tui`
+(#119), so `maestro --daemon-url http://host:7070` works as well. Builds
+without the `tui` feature have no UI to open and print help instead (exit 0).
 Drop the `tui` feature to skip it on hosts that don't need the UI surface
 (`--no-default-features --features cli,daemon`).
 
@@ -131,24 +134,46 @@ cover every v1 action — only override what you want to change:
 
 ```toml
 [tui]
+theme = "dark"              # see the theme list below
 leader = "ctrl-a"            # one byte that escapes Insert mode
-chord_timeout_ms = 1000      # how long to hold a partial chord like `g`
+chord_timeout_ms = 1000      # how long to hold a partial chord like `ctrl-w`
 
 [tui.keymap.normal]
 "i"            = "EnterInsert"
-"s"            = "OpenSpawnModal"
+"s"            = "NewDraftPane"
 "x"            = "KillHighlighted"
 "?"            = "ShowHelp"
-"ctrl-t"       = "NewTab"
-"g t"          = "NextTab"
 "ctrl-w h"     = "FocusSidebar"
 "enter"        = "AttachHighlighted"
+"pageup"       = "ScrollPanePageUp"
+"pagedown"     = "ScrollPanePageDown"
 
 [tui.keymap.insert]
 # (leader is added automatically as LeaveInsert; only override here when you
 # want extra Insert-mode bindings)
 ```
 
+`theme` selects the complete TUI palette. `dark` is the default and follows
+Maestro's terminal-native dark product palette; `light` is its light peer;
+`ansi` uses the terminal's named ANSI colours for terminals without truecolour.
+The remaining presets adapt well-known editor themes, with individual colours
+lifted or darkened where the originals fall short of the WCAG AA contrast
+floors the palette tests assert:
+
+| name              | based on         |
+|-------------------|------------------|
+| `solarized-dark`  | Solarized Dark   |
+| `solarized-light` | Solarized Light  |
+| `catppuccin`      | Catppuccin Mocha |
+| `github-dark`     | GitHub Dark      |
+| `github-light`    | GitHub Light     |
+| `tokyo-night`     | Tokyo Night      |
+| `gruvbox`         | Gruvbox Dark     |
+| `nord`            | Nord             |
+| `dracula`         | Dracula          |
+
+An unknown name is rejected as an `[tui].theme` configuration error.
+
 The full action vocabulary is the `Action` enum in
 `crates/maestro-tui/src/action.rs`.
 

docs/SIDEBAR.md

@@ -0,0 +1,141 @@
+# SIDEBAR.md — the session card contract
+
+One rule for how a session is rendered as a card in the sidebar, so the web
+sidebar (#107) and the TUI sidebar (#108) describe a session the same way.
+Read this before changing either. Both clients implement exactly what is
+written here; if it needs to change, change it here first.
+
+A card is always two lines: **line 1** and **line 2**.
+
+## Line 1 — name
+
+- Left: the session name — `metadata.name` if present, else the command line
+  (same fallback both clients already use).
+- In the web client, **spawn similar** (`⧉`) and **kill** (`✕`) remain buttons
+  anchored on the right. The TUI omits those glyphs because its actions are
+  keyboard-driven and the icons do not identify their keys.
+- The name truncates with `…` at the available width. In the web client it
+  must stop before the action buttons; in the TUI it may use the full row.
+
+Line 1 carries no badges. The `⚠ blocked work` badge (#83) and the `exited`
+badge move off this row into line 2.
+
+## Line 2 — meta line (adaptive)
+
+Line 2 always renders — never an empty placeholder row either, since its
+unconditional fragments (see below) always have something to show. Its
+*fragments* are adaptive: some show only when their trigger holds. The line
+itself is not.
+
+Line 2 reads left to right:
+
+```
+<dot> [<duration>] [<detail>] [<blocked work> | exited] <command>
+```
+
+Its minimum content is therefore the dot and the command.
+
+`<dot>` is a single filled glyph (`●` on both clients) carrying the activity
+state's colour, and `<duration>` follows in the same colour when shown. There
+is no state word and no second badge: the dot exists so the state is still
+legible when a row is dimmed or the terminal renders the duration in the
+default fg. The dot is an unconditional part of line 2; the bracketed
+fragments appear only when their trigger holds.
+
+`<duration>` renders only once the session has been held in its current
+activity state longer than **30 seconds** (`activity_since` from #102) — under
+that threshold the duration is absent and the dot renders alone. A payload
+that predates #102 (no usable `activity_since`) likewise contributes no
+duration — the dot still renders. This rule now governs only the duration
+fragment; it no longer decides whether line 2 exists.
+
+`<detail>` is an agent-reported string (#105) — e.g. why a session is in
+`Error`. It sits right after the duration, in the muted style, and shows only
+while an agent-reported state is in force (see Precedence): when the report
+lapses at its TTL or is replaced, the detail goes with it. The detail
+truncates with `…` ahead of the trailing fragments — a long detail never
+pushes `<blocked work>`, `exited`, or `<command>` off the line, and neither
+client ever lets it wrap.
+
+`<command>` is unconditional and muted: the session's command line, shown on
+every card in both clients — no omission in the TUI, no name-vs-command
+comparison gating it. A session named by its command line then shows the same
+string on both lines; that is accepted, the price of a row that never changes
+height.
+
+## Colour per activity state
+
+The state word is never spelled out — the colour carries it.
+
+| Activity state   | Web token | TUI palette role |
+| ---------------- | --------- | ---------------- |
+| `Active`         | `--live`  | `active`         |
+| `Idle`           | `--muted` | `idle`           |
+| `AwaitingInput`  | `--warn`  | `awaiting`       |
+| `Error`          | `--danger`| `error`          |
+
+Web tokens resolve per theme automatically (`styles.css` defines dark, light,
+and `prefers-color-scheme` variants for each). The TUI names roles, not
+colours: a role's value comes from the active palette
+(`maestro-tui/src/palette.rs`), never from a colour spelled out at the use
+site.
+
+A palette holds one role set per **surface** — the card surface every card
+sits on, and the selection surface the highlighted card swaps in — so each
+state role resolves to the value picked for the surface it is painted on. The
+highlighted card therefore takes its state colours from the selection
+surface; a colour chosen for the card background is never painted onto the
+selection background. Contrast is a property of the palette (values are RGB)
+and is asserted in the palette's tests, not left to the terminal theme.
+
+The duration text inherits its state's colour; the blocked-work, exited and
+command fragments use the surface's `muted` role, since the ⚠ glyph already
+signals severity.
+
+## Duration format
+
+Time spent in the **current activity state**, sourced from `activity_since`
+(#102) — *not* time since spawn, and *not* time since last PTY output
+(`last_activity_at`). Both clients compute it identically:
+
+- `< 60s` → whole seconds, floored: `30s`
+- `< 60m` → whole minutes, floored: `4m`
+- `≥ 60m` → whole hours, floored: `2h`
+
+No days unit, no seconds inside minutes, no rounding up. Floor everywhere so
+the counter never shows a duration the state hasn't actually reached yet.
+Clock granularity: re-render at least once every 30s while visible so the
+cutover points land within one tick.
+
+## Precedence
+
+An agent-reported `ActivityState` (#105) overrides the daemon's inference for
+**five minutes** (the TTL is fixed by the daemon; re-reporting extends it).
+When the TTL expires, inference resumes and the session's reported detail —
+if any — clears with the report. Clients never blend the two: whichever source
+is in force supplies both the colour and the clock for `activity_since`.
+
+Two rulings specific to a reported `Error` (#114):
+
+- **The five-minute TTL applies to `Error` like to any other state.** A
+  session that failed is still failed after five minutes, but a card pinned
+  red forever lies once the session moves on; when the report lapses the card
+  returns to the daemon's own inference — usually `Idle` for a session that
+  has gone quiet.
+- **Only a new report clears an `Error` before its TTL.** The next
+  `ActivityState` of any kind replaces it (with #106's hook that is typically
+  `PreToolUse` → `Active` when the user prompts again). PTY output and
+  process changes do not clear it — only the agent itself may withdraw what
+  the agent itself reported. Re-reporting `Error` extends the TTL rather than
+  stacking reports.
+
+If a client receives an `ActivityState` variant it does not know, it must not
+fail rendering: treat it as `Idle` (neutral/dim, line-2 rules apply as usual)
+until the daemon sends a variant it does know. Rust clients deserialize
+activity leniently for the same reason.
+
+Leniency runs one way only. It covers a client *reading* a newer daemon, where
+dropping the whole session would be worse than dimming one card. A report
+arriving at `POST /api/sessions/:id/activity` is parsed strictly and an unknown
+state is a 4xx: an agent posting a state the daemon does not know is a bug in
+the agent, and answering 204 would hide it.

web/src/activity.test.ts

@@ -0,0 +1,60 @@
+import { describe, expect, it } from "vitest";
+
+import {
+  activityColorSlug,
+  activityDurationLabel,
+  activityHeldMs,
+} from "./activity.js";
+
+describe("activityHeldMs", () => {
+  it("measures time spent in the current state", () => {
+    const now = Date.now();
+    const since = new Date(now - 90_000).toISOString();
+    expect(activityHeldMs(since, now)).toBe(90_000);
+  });
+
+  it("returns null for payloads that predate #102 (epoch default)", () => {
+    expect(activityHeldMs(undefined, Date.now())).toBeNull();
+    expect(activityHeldMs(new Date(0).toISOString(), Date.now())).toBeNull();
+  });
+
+  it("returns null for unparseable timestamps", () => {
+    expect(activityHeldMs("not-a-time", Date.now())).toBeNull();
+  });
+
+  it("never goes negative", () => {
+    const now = Date.now();
+    expect(activityHeldMs(new Date(now + 5_000).toISOString(), now)).toBe(0);
+  });
+});
+
+describe("activityDurationLabel (#102)", () => {
+  it("floors whole seconds under a minute", () => {
+    expect(activityDurationLabel(30_400)).toBe("30s");
+    expect(activityDurationLabel(59_900)).toBe("59s");
+  });
+
+  it("floors whole minutes under an hour", () => {
+    expect(activityDurationLabel(60_000)).toBe("1m");
+    expect(activityDurationLabel(4 * 60_000 + 59_999)).toBe("4m");
+  });
+
+  it("floors whole hours from an hour up, with no days unit", () => {
+    expect(activityDurationLabel(60 * 60_000)).toBe("1h");
+    expect(activityDurationLabel(2 * 3_600_000 + 59 * 60_000 + 59_999)).toBe("2h");
+    expect(activityDurationLabel(26 * 3_600_000)).toBe("26h");
+  });
+});
+
+describe("activityColorSlug", () => {
+  it("maps each known state to its contract slug", () => {
+    expect(activityColorSlug("Active")).toBe("active");
+    expect(activityColorSlug("Idle")).toBe("idle");
+    expect(activityColorSlug("AwaitingInput")).toBe("awaiting-input");
+    expect(activityColorSlug("Error")).toBe("error");
+  });
+
+  it("treats an unknown variant as idle so rendering never fails", () => {
+    expect(activityColorSlug("Teleported")).toBe("idle");
+  });
+});

web/src/activity.ts

@@ -0,0 +1,44 @@
+// docs/SIDEBAR.md: the session card's meta line — activity colour mapping and
+// the shared duration format. Both clients compute it identically; the TUI
+// mirrors this in crates/maestro-tui.
+
+import type { ActivityState, IsoTimestamp } from "./types.js";
+
+/** A state held shorter than this has no duration fragment. */
+export const META_LINE_MIN_HOLD_MS = 30_000;
+
+// Payloads predating #102 default `activity_since` to the Unix epoch; anything
+// implausibly old is treated as "never observed" rather than a huge duration.
+const PLAUSIBLE_EPOCH_MS = Date.UTC(2010, 0, 1);
+
+export function activityHeldMs(since: IsoTimestamp | undefined, now: number): number | null {
+  if (!since) return null;
+  const t = Date.parse(since);
+  if (Number.isNaN(t) || t < PLAUSIBLE_EPOCH_MS) return null;
+  return Math.max(0, now - t);
+}
+
+/** `<60s` → whole seconds, `<60m` → whole minutes, else whole hours. Floored
+ *  everywhere so the counter never shows a duration the state hasn't reached. */
+export function activityDurationLabel(heldMs: number): string {
+  const s = Math.floor(heldMs / 1000);
+  if (s < 60) return `${s}s`;
+  const m = Math.floor(s / 60);
+  if (m < 60) return `${m}m`;
+  return `${Math.floor(m / 60)}h`;
+}
+
+/** CSS hook for the state's colour (`styles.css` maps slugs to tokens). An
+ *  unknown variant degrades to idle so rendering never fails (Precedence). */
+export function activityColorSlug(state: ActivityState | string): string {
+  switch (state) {
+    case "Active":
+      return "active";
+    case "AwaitingInput":
+      return "awaiting-input";
+    case "Error":
+      return "error";
+    default:
+      return "idle";
+  }
+}

web/src/attach.ts

@@ -123,7 +123,8 @@ export function createAttachConnection(
   //     wheel events so xterm encodes them as mouse-wheel reports the app reads,
   //     scrolling *its* content (the only scroll that exists on the alt screen).
   //   • alt screen with no mouse tracking → nothing to do; the app owns input.
-  // `touch-action: pan-y` (CSS) tells the browser we handle the Y gesture.
+  // `touch-action: none` (CSS) keeps the browser from cancelling the custom
+  // gesture stream; only the terminal surface opts out of native page panning.
   {
     const vp = el.querySelector(".xterm-viewport") as HTMLElement | null;
     const screen = el.querySelector(".xterm-screen") as HTMLElement | null;

web/src/catalog.test.ts

@@ -104,3 +104,168 @@ describe("blocked-work indicator (#83)", () => {
     expect(confirmations).toEqual(['Kill session "claude"?']);
   });
 });
+
+describe("agent-reported detail (#112)", () => {
+  const ago = (ms: number): string => new Date(Date.now() - ms).toISOString();
+
+  it("renders the reported detail right after the duration on line 2", () => {
+    const s = session({
+      id: "aaaaaaaa-0000-0000-0000-000000000020",
+      status: "Dead",
+      activity: "Error",
+      activity_since: ago(90_000),
+      activity_detail: "cargo build failed",
+    });
+    const el = renderSidebar(storeWith([s])).el;
+    const line2 = rowFor(el, s.id)?.querySelector<HTMLElement>(".card-line2");
+    expect(line2?.querySelector(".activity-detail")?.textContent).toBe("cargo build failed");
+    const order = [...line2!.children].map((c) => c.className);
+    expect(order.indexOf("activity-detail")).toBeGreaterThan(order.indexOf("activity-duration"));
+    expect(order.indexOf("activity-detail")).toBeLessThan(
+      order.findIndex((c) => c.startsWith("card-flag")),
+    );
+  });
+
+  it("omits the detail when no report is in force", () => {
+    const s = session({
+      id: "aaaaaaaa-0000-0000-0000-000000000021",
+      activity: "Active",
+      activity_since: ago(90_000),
+    });
+    const el = renderSidebar(storeWith([s])).el;
+    expect(rowFor(el, s.id)?.querySelector(".activity-detail")).toBeNull();
+  });
+});
+
+describe("session cards (#107)", () => {
+  const ago = (ms: number): string => new Date(Date.now() - ms).toISOString();
+
+  it("keeps the name and the actions in the same flow line, actions reserving their width", () => {
+    const s = session({ id: "aaaaaaaa-0000-0000-0000-000000000010" });
+    const el = renderSidebar(storeWith([s])).el;
+    const line1 = rowFor(el, s.id)?.querySelector<HTMLElement>(".card-line1");
+    expect(line1).not.toBeNull();
+    // Same flex line ⇒ the name truncates before it can ever reach the buttons.
+    expect(line1?.querySelector(".leaf-name")).not.toBeNull();
+    expect(line1?.querySelector(".leaf-actions")).toBe(line1?.lastElementChild);
+  });
+
+  it("always renders line 2 for a freshly spawned session", () => {
+    const s = session({
+      id: "aaaaaaaa-0000-0000-0000-000000000011",
+      activity: "Active",
+      activity_since: ago(5_000),
+    });
+    const el = renderSidebar(storeWith([s])).el;
+    const line2 = rowFor(el, s.id)?.querySelector<HTMLElement>(".card-line2");
+    expect(line2).not.toBeNull();
+    expect(line2?.querySelector(".activity-dot")).not.toBeNull();
+    expect(line2?.querySelector(".activity-duration")).toBeNull();
+    expect(line2?.querySelector(".leaf-cmd")?.textContent).toBe("claude");
+  });
+
+  it("shows dot + floored duration once the state has been held past 30s", () => {
+    const s = session({
+      id: "aaaaaaaa-0000-0000-0000-000000000012",
+      activity: "Active",
+      activity_since: ago(4 * 60_000 + 30_000),
+    });
+    const el = renderSidebar(storeWith([s])).el;
+    const line2 = rowFor(el, s.id)?.querySelector<HTMLElement>(".card-line2");
+    expect(line2?.dataset.activity).toBe("active");
+    expect(line2?.querySelector(".activity-dot")).not.toBeNull();
+    expect(line2?.querySelector(".activity-duration")?.textContent).toBe("4m");
+  });
+
+  it("renders the command when the session name equals it", () => {
+    const s = session({
+      id: "aaaaaaaa-0000-0000-0000-00000000001b",
+      command: "claude",
+      metadata: { name: "claude" },
+    });
+    const el = renderSidebar(storeWith([s])).el;
+    expect(rowFor(el, s.id)?.querySelector(".card-line2 .leaf-cmd")?.textContent).toBe("claude");
+  });
+
+  it("maps each activity state to its contract slug", () => {
+    const mk = (id: string, activity: string) =>
+      session({
+        id,
+        activity: activity as Session["activity"],
+        status: "Running",
+        activity_since: ago(90_000),
+      });
+    const idle = mk("aaaaaaaa-0000-0000-0000-000000000013", "Idle");
+    const wait = mk("aaaaaaaa-0000-0000-0000-000000000014", "AwaitingInput");
+    const error = mk("aaaaaaaa-0000-0000-0000-000000000015", "Error");
+    const el = renderSidebar(storeWith([idle, wait, error])).el;
+    expect(rowFor(el, idle.id)?.querySelector(".card-line2")?.getAttribute("data-activity")).toBe(
+      "idle",
+    );
+    expect(rowFor(el, wait.id)?.querySelector(".card-line2")?.getAttribute("data-activity")).toBe(
+      "awaiting-input",
+    );
+    expect(rowFor(el, error.id)?.querySelector(".card-line2")?.getAttribute("data-activity")).toBe(
+      "error",
+    );
+  });
+
+  it("treats an unknown activity variant as idle instead of failing to render", () => {
+    const s = session({
+      id: "aaaaaaaa-0000-0000-0000-000000000016",
+      activity: "Teleported" as Session["activity"],
+      activity_since: ago(120_000),
+    });
+    const el = renderSidebar(storeWith([s])).el;
+    const line2 = rowFor(el, s.id)?.querySelector(".card-line2");
+    expect(line2?.getAttribute("data-activity")).toBe("idle");
+    expect(line2?.querySelector(".activity-duration")?.textContent).toBe("2m");
+  });
+
+  it("moves blocked work onto line 2 in the shared phrasing", () => {
+    const s = session({
+      id: "aaaaaaaa-0000-0000-0000-000000000017",
+      blocked_work: { uncommitted_files: 3, unpushed_commits: 2 },
+    });
+    const el = renderSidebar(storeWith([s])).el;
+    const line2 = rowFor(el, s.id)?.querySelector<HTMLElement>(".card-line2");
+    expect(line2?.textContent).toContain("⚠");
+    expect(line2?.textContent).toContain("3 uncommitted files, 2 unpushed commits");
+    // Line 1 carries no badges.
+    expect(rowFor(el, s.id)?.querySelector(".leaf-badge")).toBeNull();
+  });
+
+  it("shows exited on line 2 for dead sessions", () => {
+    const s = session({
+      id: "aaaaaaaa-0000-0000-0000-000000000018",
+      status: "Dead",
+    });
+    const el = renderSidebar(storeWith([s])).el;
+    const line2 = rowFor(el, s.id)?.querySelector<HTMLElement>(".card-line2");
+    expect(line2?.textContent).toContain("exited");
+  });
+
+  it("carries the state word only in tooltips and aria labels, never as text", () => {
+    const s = session({
+      id: "aaaaaaaa-0000-0000-0000-000000000019",
+      command: "claude",
+      metadata: { name: "worker" },
+      activity: "AwaitingInput",
+      activity_since: ago(90_000),
+    });
+    const el = renderSidebar(storeWith([s])).el;
+    const row = rowFor(el, s.id) as HTMLElement;
+    const dot = row.querySelector<HTMLElement>(".activity-dot");
+    expect(dot?.getAttribute("title")).toContain("Awaiting input");
+    expect(dot?.getAttribute("aria-label")).toContain("Awaiting input");
+    expect(row.textContent).not.toMatch(/awaiting.?input/i);
+  });
+
+  it("keeps the attach navigation and depth indentation", () => {
+    const s = session({ id: "aaaaaaaa-0000-0000-0000-00000000001a" });
+    const el = renderSidebar(storeWith([s])).el;
+    const row = rowFor(el, s.id) as HTMLAnchorElement;
+    expect(row.getAttribute("href")).toBe("#/attach/aaaaaaaa-0000-0000-0000-00000000001a");
+    expect(row.style.paddingLeft).toMatch(/^\d+(\.\d+)?px$/);
+  });
+});

web/src/catalog.ts

@@ -4,6 +4,12 @@ import { HUD_TOGGLE_EVENT, isHudEnabled, toggleHud } from "./debug.js";
 import { CatalogStore } from "./events.js";
 import type { Session } from "./types.js";
 import { abbreviateFolderName, formatInTheWay, sessionBlockers, sessionName } from "./types.js";
+import {
+  activityColorSlug,
+  activityDurationLabel,
+  activityHeldMs,
+  META_LINE_MIN_HOLD_MS,
+} from "./activity.js";
 import type { TreeNode } from "./tree.js";
 import { buildTree } from "./tree.js";
 import { createThemeToggle } from "./theme.js";
@@ -17,6 +23,39 @@ export function requestOpenSpawn(): void {
 
 const collapsed = new Set<string>();
 
+// docs/SIDEBAR.md: the state word is never rendered — the dot's colour carries
+// it. It survives only in tooltips/aria labels so meaning is not colour-only.
+const STATE_WORDS: Record<string, string> = {
+  active: "Active",
+  idle: "Idle",
+  "awaiting-input": "Awaiting input",
+  error: "Error",
+};
+
+function metaLine(s: Session, now: number): string {
+  const dead = s.status === "Dead";
+  const blockers = sessionBlockers(s);
+  const slug = activityColorSlug(s.activity ?? "Idle");
+  const stateWord = STATE_WORDS[slug] ?? STATE_WORDS.idle;
+  const held = activityHeldMs(s.activity_since, now);
+  const duration =
+    held !== null && held >= META_LINE_MIN_HOLD_MS ? activityDurationLabel(held) : null;
+
+  const fragments = [
+    `<span class="activity-dot" role="img" title="${escapeHtml(stateWord)}" aria-label="${escapeHtml(stateWord)}"></span>`,
+    duration ? `<span class="activity-duration">${duration}</span>` : "",
+    s.activity_detail
+      ? `<span class="activity-detail">${escapeHtml(s.activity_detail)}</span>`
+      : "",
+    blockers
+      ? `<span class="card-flag leaf-blocked" title="Kill will be refused unless forced">⚠ ${escapeHtml(formatInTheWay(blockers))}</span>`
+      : "",
+    dead ? `<span class="card-flag">exited</span>` : "",
+    `<span class="card-flag leaf-cmd" title="${escapeHtml(s.command)}">${escapeHtml(s.command)}</span>`,
+  ];
+  return `<span class="card-line2" data-activity="${slug}">${fragments.join("")}</span>`;
+}
+
 function renderNode(node: TreeNode, depth: number): HTMLElement {
   if (node.kind === "folder") {
     const wrap = document.createElement("div");
@@ -52,30 +91,31 @@ function renderNode(node: TreeNode, depth: number): HTMLElement {
   }
 
   const s = node.session;
+  const now = Date.now();
   const row = document.createElement("a");
-  row.className = "tree-leaf";
+  row.className = "tree-leaf session-card";
   row.href = `#/attach/${encodeURIComponent(s.id)}`;
   row.style.paddingLeft = `${depth * 16 + 8}px`;
   row.dataset.sessionId = s.id;
   const running = s.status === "Running";
   row.dataset.status = running ? "running" : "dead";
   const name = sessionName(s);
-  row.setAttribute("aria-label", `${name}, ${running ? "running" : "exited"}`);
+  const stateWord =
-  // The directory is the enclosing folder, so only surface the command — and
+    STATE_WORDS[activityColorSlug(s.activity ?? "Idle")] ?? STATE_WORDS.idle;
-  // only when it isn't already what the name shows.
+  row.setAttribute(
-  const showCmd = s.command !== name;
+    "aria-label",
-  // #83: warn on the row itself, in `formatInTheWay`'s shared phrasing, so
+    `${name}, ${running ? "running" : "exited"}, ${stateWord}`,
-  // "this will be refused" is visible before the kill is attempted.
+  );
-  const blockers = sessionBlockers(s);
+  // docs/SIDEBAR.md: line 1 reserves action width, and line 2 is unconditional.
   row.innerHTML = `
-    <span class="leaf-name">${escapeHtml(name)}</span>
+    <span class="card-line1">
-    ${showCmd ? `<span class="leaf-meta"><span class="leaf-cmd">${escapeHtml(s.command)}</span></span>` : ""}
+      <span class="leaf-name">${escapeHtml(name)}</span>
-    ${running ? "" : `<span class="leaf-badge">exited</span>`}
+      <span class="leaf-actions">
-    ${blockers ? `<span class="leaf-badge leaf-blocked" title="Kill will be refused unless forced">⚠ ${escapeHtml(formatInTheWay(blockers))}</span>` : ""}
+        <button class="leaf-act leaf-clone" type="button" title="Spawn similar" aria-label="Spawn similar to ${escapeHtml(name)}">⧉</button>
-    <span class="leaf-actions">
+        <button class="leaf-act leaf-kill" type="button" title="Kill session" aria-label="Kill ${escapeHtml(name)}">✕</button>
-      <button class="leaf-act leaf-clone" type="button" title="Spawn similar" aria-label="Spawn similar to ${escapeHtml(name)}">⧉</button>
+      </span>
-      <button class="leaf-act leaf-kill" type="button" title="Kill session" aria-label="Kill ${escapeHtml(name)}">✕</button>
     </span>
+    ${metaLine(s, now)}
   `;
   const similarBtn = row.querySelector(".leaf-clone") as HTMLButtonElement;
   similarBtn.addEventListener("click", (ev) => {
@@ -395,6 +435,13 @@ export function renderSidebar(store: CatalogStore, opts: SidebarOptions = {}): S
 
   const unsubscribe = store.subscribe(refresh);
 
+  // Contract granularity: re-render at least every 30s while visible so the
+  // duration cutover points land within one tick.
+  const clock = setInterval(() => {
+    if (document.visibilityState !== "visible") return;
+    refresh();
+  }, 30_000);
+
   return {
     el,
     setActive(id: string | null) {
@@ -410,6 +457,7 @@ export function renderSidebar(store: CatalogStore, opts: SidebarOptions = {}): S
       applyHighlights();
     },
     dispose() {
+      clearInterval(clock);
       document.removeEventListener("catalog-rerender", rerenderHandler);
       unsubscribe();
     },

web/src/kit.ts

@@ -59,20 +59,28 @@ function leafRow(opts: {
   status: "running" | "dead";
   active?: boolean;
   indent?: number;
+  activity?: "active" | "idle" | "awaiting-input" | "error";
+  duration?: string;
 }): HTMLElement {
-  const row = h("a", "tree-leaf");
+  const row = h("a", "tree-leaf session-card");
   (row as HTMLAnchorElement).href = "#/kit";
   row.dataset.status = opts.status;
   if (opts.active) row.classList.add("is-active");
   row.style.paddingLeft = `${(opts.indent ?? 0) * 16 + 8}px`;
+  const flags = [
+    opts.status === "dead" ? `<span class="card-flag">exited</span>` : "",
+    opts.cmd !== opts.name ? `<span class="card-flag leaf-cmd">${opts.cmd}</span>` : "",
+  ].join("");
   row.innerHTML = `
-    <span class="leaf-name">${opts.name}</span>
+    <span class="card-line1">
-    ${opts.cmd !== opts.name ? `<span class="leaf-meta"><span class="leaf-cmd">${opts.cmd}</span></span>` : ""}
+      <span class="leaf-name">${opts.name}</span>
-    ${opts.status === "dead" ? `<span class="leaf-badge">exited</span>` : ""}
+      <span class="leaf-actions">
-    <span class="leaf-actions">
+        <button class="leaf-act leaf-clone" type="button" title="Spawn similar">⧉</button>
-      <button class="leaf-act leaf-clone" type="button" title="Spawn similar" aria-label="Spawn similar to ${opts.name}">⧉</button>
+        <button class="leaf-act leaf-kill" type="button" title="Kill session">✕</button>
-      <button class="leaf-act leaf-kill" type="button" title="Kill session" aria-label="Kill ${opts.name}">✕</button>
+      </span>
-    </span>`;
+    </span>
+    ${opts.activity ? `<span class="card-line2" data-activity="${opts.activity}"><span class="activity-dot" title="${opts.activity}"></span><span class="activity-duration">${opts.duration ?? ""}</span>${flags}</span>` : ""}
+  `;
   return row;
 }
 
@@ -190,14 +198,17 @@ export function renderKit(): HTMLElement {
   // --- chips & badges ---
   {
     const { el, body } = section("Chips & badges", "Status-bearing pills and counts.");
+    const activeLine = h(
+      "span",
+      "card-line2",
+      `<span class="activity-dot"></span><span class="activity-duration">4m</span>`,
+    );
+    activeLine.setAttribute("data-activity", "active");
     body.append(
       specimen("session-tally", h("span", "session-tally", "6 sessions · 5 live")),
       specimen("folder-count", h("span", "folder-count", "4")),
-      specimen("leaf-badge", h("span", "leaf-badge", "exited")),
+      specimen("card-line2 · active", activeLine),
-      specimen(
+      specimen("attach-state · open", h("span", "attach-state", "live")),
-        "attach-state · open",
-        h("span", "attach-state", "live"),
-      ),
     );
     (body.lastElementChild?.querySelector(".attach-state") as HTMLElement)?.setAttribute(
       "data-state",
@@ -215,19 +226,56 @@ export function renderKit(): HTMLElement {
   {
     const { el, body } = section(
       "Session rows — nested by host, then directory",
-      "The working directory (home collapsed to ~) is the nesting, and single-child chains fold into one node like ~/git/maestro. “Alive” is a faint row wash; exited rows recede with a badge; the open session is highlighted.",
+      "docs/SIDEBAR.md cards: line 1 is name + top-right actions (the name truncates before it can reach them); line 2 only when there's something to say — dot + duration in the state's colour, then blocked-work / exited fragments.",
     );
     const list = h("div", "kit-tree");
     list.append(
       folderHeader("~/git/maestro", 3, 0),
       folderHeader("web", 2, 1),
       leafRow({ name: "redesign", cmd: "claude", status: "running", indent: 2 }),
-      leafRow({ name: "dev-server", cmd: "vite dev", status: "running", indent: 2, active: true }),
+      leafRow({
+        name: "dev-server",
+        cmd: "vite dev",
+        status: "running",
+        indent: 2,
+        active: true,
+        activity: "active",
+        duration: "4m",
+      }),
       folderHeader("crates/daemon", 1, 1),
-      leafRow({ name: "daemon-work", cmd: "claude", status: "running", indent: 2 }),
+      leafRow({
+        name: "daemon-work",
+        cmd: "claude",
+        status: "running",
+        indent: 2,
+        activity: "awaiting-input",
+        duration: "12s",
+      }),
+      leafRow({
+        name: "flaky-agent",
+        cmd: "claude",
+        status: "running",
+        indent: 2,
+        activity: "error",
+        duration: "2h",
+      }),
       folderHeader("~/work/acme", 2, 0),
-      leafRow({ name: "billing-api", cmd: "claude", status: "running", indent: 1 }),
+      leafRow({
-      leafRow({ name: "scratch", cmd: "bash", status: "dead", indent: 1 }),
+        name: "billing-api",
+        cmd: "claude",
+        status: "running",
+        indent: 1,
+        activity: "idle",
+        duration: "26m",
+      }),
+      leafRow({
+        name: "scratch",
+        cmd: "bash",
+        status: "dead",
+        indent: 1,
+        activity: "idle",
+        duration: "5h",
+      }),
       leafRow({ name: "monitor", cmd: "btop", status: "running", indent: 0 }),
     );
     body.classList.add("kit-tree-host");

web/src/main.ts

@@ -272,7 +272,11 @@ function showMultiView(): void {
 // cloned session's dir + command.
 function requestOpenSpawn(): void {
   showMultiView();
-  mv.openDraft();
+  // A new tab, not a split of the pane you were reading (#100). "Spawn
+  // similar" and the fast-forward key below deliberately keep the old
+  // behaviour: both act on the session in front of you, so a split beside it
+  // is the point.
+  mv.openDraft(undefined, { newTab: true });
 }
 document.addEventListener(OPEN_SPAWN_EVENT, () => requestOpenSpawn());
 document.addEventListener("catalog-spawn-similar", (ev) => {

web/src/multiview.test.ts

@@ -282,3 +282,54 @@ describe("multiview pane-drag swap (#73)", () => {
     expect(nameInputOf(leaf2).value).toBe("west");
   });
 });
+
+describe("openDraft newTab (#100)", () => {
+  beforeEach(() => {
+    stubFetch();
+    document.body.replaceChildren();
+  });
+
+  afterEach(() => {
+    vi.unstubAllGlobals();
+  });
+
+  it("opens its own tab instead of splitting the focused session", async () => {
+    const layout = emptyLayout();
+    const tab = layout.tabs[0];
+    const first = splitLeaf(tab, "", "s1", "row", true);
+    tab.focusedLeafId = first;
+    const mv = makeMv(layout);
+    document.body.appendChild(mv.el);
+    mv.render();
+
+    mv.openDraft(undefined, { newTab: true });
+    await flush();
+
+    expect(layout.tabs).toHaveLength(2);
+    // The tab you were reading is untouched: still one pane, still its session.
+    const original = leaves(layout.tabs[0].root);
+    expect(original).toHaveLength(1);
+    expect(original[0].sessionId).toBe("s1");
+    // The draft is alone in the new, now-active tab.
+    const fresh = leaves(layout.tabs[1].root);
+    expect(fresh).toHaveLength(1);
+    expect(fresh[0].sessionId).toBeNull();
+    expect(fresh[0].draft).not.toBeNull();
+    expect(layout.activeTabId).toBe(layout.tabs[1].id);
+  });
+
+  it("still splits when newTab is not asked for", async () => {
+    const layout = emptyLayout();
+    const tab = layout.tabs[0];
+    tab.focusedLeafId = splitLeaf(tab, "", "s1", "row", true);
+    const mv = makeMv(layout);
+    document.body.appendChild(mv.el);
+    mv.render();
+
+    mv.openDraft();
+    await flush();
+
+    expect(layout.tabs).toHaveLength(1);
+    expect(leaves(tab.root)).toHaveLength(2);
+  });
+});

web/src/multiview.ts

@@ -57,7 +57,7 @@ export interface MultiView {
   /** Open a draft pane (issue #62): reuse the focused pane if it is already
    *  empty, otherwise split the focused pane. `seed` pre-fills the form
    *  ("Spawn similar" clones a session's cwd + command). */
-  openDraft: (seed?: Partial<Draft>) => void;
+  openDraft: (seed?: Partial<Draft>, opts?: { newTab?: boolean }) => void;
   /** Start dragging a sidebar session into the canvas (issue #32). The
    *  controller owns drag-vs-tap: a tap lets the row's normal click open it, a
    *  drag shows drop zones to place it. */
@@ -412,9 +412,18 @@ export function createMultiView(opts: MultiViewOptions): MultiView {
     opts.onOpenSessionsChange?.();
   }
 
-  function openDraft(seed?: Partial<Draft>): void {
+  function openDraft(seed?: Partial<Draft>, opts?: { newTab?: boolean }): void {
-    const tab = activeTab(layout);
     const draft = (): Draft => ({ command: "", cwd: "", name: "", ...seed });
+    if (opts?.newTab) {
+      // Spawn opens its own tab rather than halving whatever you were reading
+      // (#100). The empty-pane reuse below still applies within a tab.
+      const fresh = addTab(layout);
+      fresh.focusedLeafId = splitLeaf(fresh, "", null, "row", true);
+      findLeaf(fresh.root!, fresh.focusedLeafId)!.draft = draft();
+      render();
+      return;
+    }
+    const tab = activeTab(layout);
     if (!tab.root || !tab.focusedLeafId || !findLeaf(tab.root, tab.focusedLeafId)) {
       // Empty tab (or stale focus): the draft becomes the first pane.
       tab.focusedLeafId = splitLeaf(tab, "", null, "row", true);

web/src/projectPicker.test.ts

@@ -34,13 +34,13 @@ function stubFetch(info: unknown, projects: Project[]): void {
   );
 }
 
-function rowPaths(form: HTMLFormElement): string[] {
+function boxPaths(form: HTMLFormElement): string[] {
-  return [...form.querySelectorAll<HTMLButtonElement>(".project-row:not(.project-other)")].map(
+  return [...form.querySelectorAll<HTMLButtonElement>(".project-box")].map(
-    (r) => r.dataset.cwd ?? "",
+    (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"]);
+    expect(boxPaths(form)).toEqual(["/home/user/fresh", "/home/user/stale"]);
-    const rows = [...form.querySelectorAll<HTMLButtonElement>(".project-row")];
+    const boxes = [...form.querySelectorAll<HTMLButtonElement>(".project-box")];
-    expect(rows[1].classList.contains("is-stale")).toBe(true);
+    expect(boxes[1].classList.contains("is-stale")).toBe(true);
-    expect(rows[0].classList.contains("is-stale")).toBe(false);
+    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"]);
+    expect(boxPaths(form)).toEqual(["/home/user/maestro"]);
-    const [mainRow, wtRow] = [
+    expect(form.querySelector(".project-box.is-worktree")).toBeNull();
-      ...form.querySelectorAll(".project-row:not(.project-other)"),
-    ];
-    expect(wtRow.classList.contains("is-worktree")).toBe(true);
-    expect(mainRow.classList.contains("is-worktree")).toBe(false);
   });
 
-  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")!;
+    const box = form.querySelector<HTMLButtonElement>(".project-box")!;
-    row.click();
+    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/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). */
@@ -130,15 +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">
@@ -147,33 +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>
-      <p class="wt-hint" hidden></p>
+        <div class="wt-body" hidden>
-      <div class="wt-body" hidden>
+          <p class="wt-repo"></p>
-        <p class="wt-repo"></p>
+          <div class="wt-mode" role="radiogroup" aria-label="Branch source">
-        <div class="wt-mode" role="radiogroup" aria-label="Branch source">
+            <label class="row-inline">
-          <label class="row-inline">
+              <input type="radio" name="worktree_branch_mode" value="new" />
-            <input type="radio" name="worktree_branch_mode" value="new" />
+              New branch
-            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">
+          <label class="wt-exist-wrap" hidden>
-            <input type="radio" name="worktree_branch_mode" value="existing" />
+            Pick a branch
-            Existing 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>
@@ -187,11 +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;
@@ -342,6 +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) {
@@ -350,13 +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();
     }
@@ -372,7 +407,11 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
       if (info.presets?.length) {
         presets = info.presets;
         renderCommandTiles();
-        applyInitialCommand();
+        if (commandTouched) {
+          reapplyActiveTile();
+        } else {
+          applyInitialCommand();
+        }
       }
     })
     .catch(() => {
@@ -399,12 +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();
@@ -421,62 +484,95 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
     if (wtEnabled.checked) scheduleGitRootProbe();
   });
 
-  function markActiveProject(activeCwd: string | null): void {
+  /** Every worktree of a group, including the group's own box when the scan
-    for (const row of recentsEl.querySelectorAll(".project-row")) {
+   * found no main checkout to nest it under. */
-      row.classList.toggle(
+  function worktreesOf(group: ProjectGroup): Project[] {
-        "is-active",
+    return [group.main, ...group.worktrees].filter((p) => p.is_worktree);
-        (row as HTMLElement).dataset.cwd === activeCwd,
+  }
-      );
+
+  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 {
+  function markActiveChoice(): void {
-    cwd = project.path;
+    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);
+    renderWorktreeChoices(group);
-    // The scan already knows this directory is inside a repo (#61): the
+    markActiveBox();
-    // toggle defaults back on and no /api/gitroot round trip is needed —
+    // Rule 4: a box that is itself a linked worktree defaults to running there.
-    // unless the directory *is* a linked worktree itself (#91): spawning
+    applyWorktreeChoice(group.main.is_worktree ? group.main.path : "new");
-    // in place is the only thing that works there, so default the toggle
+  }
-    // off. Turning it back on by hand still tries (and fails with git's
+
-    // own message), which is deliberate (#91 non-goal).
+  function applyWorktreeChoice(choice: WorktreeChoice): void {
-    wtEnabled.checked = !project.is_worktree;
+    const group = selectedGroup;
-    if (project.is_worktree) {
+    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;
-    } else {
-      applyProjectRepo(project.base_repo ?? project.path);
     }
     emit();
-    // Picking a project pre-selects the command it was last used with.
+    // The chosen directory pre-selects the command it was last used with.
-    const match = presets.find((p) => p.command === project.last_command && p.command !== "");
+    const match = presets.find((p) => p.command === target.last_command && p.command !== "");
     if (match) selectPreset(match.id);
   }
 
-  let discovered: Project[] = []; // daemon snapshot, daemon-sorted
+  /** Groups with at least one member (itself or a worktree) matching `query`. */
+  function visibleGroups(query: string): ProjectGroup[] {
+    return groups.filter((g) => filterProjects([g.main, ...g.worktrees], query).length > 0);
+  }
 
   function renderProjects(): void {
-    recentsEl.replaceChildren();
+    projectsEl.replaceChildren();
-    const sorted = sortProjects(filterProjects(discovered, filterInput.value), new Date());
+    groups = groupProjects(sortProjects(discovered, new Date()));
-    for (const group of groupProjects(sorted)) {
+    const visible = visibleGroups(filterInput.value);
-      recentsEl.appendChild(projectRow(group.main));
+    for (const group of visible) projectsEl.appendChild(projectBox(group));
-      for (const wt of group.worktrees) recentsEl.appendChild(projectRow(wt));
+    if (discovered.length > 0 && visible.length === 0) {
-    }
-    if (discovered.length > 0 && sorted.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());
+    markActiveBox();
-    markActiveProject(cwdRawWrap.hidden ? cwd : null);
   }
 
   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 {
@@ -487,12 +583,13 @@ 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);
       }
@@ -509,34 +606,66 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
     emit();
   }
 
-  function projectRow(project: Project): HTMLElement {
+  /** Put the two steps back on a restored draft's cwd, without re-running the
-    const row = document.createElement("button");
+   * side effects of a fresh pick. */
-    row.type = "button";
+  function restoreSelection(path: string): boolean {
-    row.className = `project-row${project.is_worktree ? " is-worktree" : ""}${
+    for (const group of groups) {
-      isStale(project, new Date()) ? " is-stale" : ""
+      const wt = worktreesOf(group).find((p) => p.path === path);
-    }`;
+      const choice: WorktreeChoice | null =
-    row.dataset.cwd = project.path;
+        wt ? wt.path : group.main.path === path ? "new" : null;
-    // Abbreviate exactly like the sidebar: home → `~`, then collapse leading
+      if (choice === null) continue;
-    // segments to initials (`~/g/n/maestro`). The full path stays in the tooltip
+      selectedGroup = group;
-    // and `dataset.cwd` (what's actually submitted).
+      worktreeChoice = choice;
-    const display = abbreviateFolderName(abbreviateCwd(project.path, homeDir));
+      renderWorktreeChoices(group);
-    row.innerHTML = `
+      markActiveChoice();
-      <span class="project-info">
+      markActiveBox();
-        <span class="project-name">${escapeHtml(project.name)}</span>
+      return true;
-        <span class="recent-dir" title="${escapeHtml(project.path)}">${display}</span>
+    }
-      </span>
+    return false;
-      <span class="recent-cmd">${escapeHtml(project.last_command ?? "")}</span>`;
-    row.addEventListener("click", () => selectProject(project));
-    return row;
   }
 
-  function otherDirRow(): HTMLElement {
+  function projectBox(group: ProjectGroup): HTMLElement {
-    const row = document.createElement("button");
+    const project = group.main;
-    row.type = "button";
+    const box = document.createElement("button");
-    row.className = "project-row project-other";
+    box.type = "button";
-    row.innerHTML = `<span class="project-info"><span class="recent-dir">Other directory…</span></span>`;
+    box.className = `project-box${isStale(project, new Date()) ? " is-stale" : ""}`;
-    row.addEventListener("click", () => showRawCwd(cwd || homeDir));
+    box.dataset.cwd = project.path;
-    return row;
+    const trees = worktreesOf(group).length;
+    // The full path, not the sidebar's `~/t/n/maestro` abbreviation: it is what
+    // tells two projects sharing a basename apart (#95).
+    const meta = [trees > 0 ? `${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 {
@@ -546,6 +675,18 @@ 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
@@ -626,6 +767,7 @@ 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;
@@ -699,6 +841,7 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
   branchSelect.addEventListener("change", () => emit());
 
   wtEnabled.addEventListener("change", () => {
+    updateWtSummary();
     emit();
     if (wtEnabled.checked) {
       resolveBaseRepo();
@@ -712,6 +855,7 @@ 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);
 
@@ -722,6 +866,43 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
   // ---- live dir autocomplete on the raw cwd input (NAP-329) ------------
   const autocomplete = attachDirAutocomplete(cwdRaw);
 
+  // ---- Enter submits from anywhere (#97) --------------------------------
+  // A project-box/wt-choice that isn't yet the active pick takes the Enter to
+  // choose it instead; the next Enter, now that it's active, submits.
+  // dirAutocomplete's own Enter (accept the highlight) already preventDefaults
+  // when it handles the key, which the `e.defaultPrevented` guard defers to.
+  // The worktree checkbox keeps Enter as a toggle (TUI parity: `WorktreeToggle`
+  // does the same) rather than folding it into the blanket-submit rule below.
+  form.addEventListener("keydown", (e) => {
+    if (e.key !== "Enter" || e.defaultPrevented) return;
+    const target = e.target as HTMLElement;
+
+    if (target === wtEnabled) {
+      e.preventDefault();
+      wtEnabled.checked = !wtEnabled.checked;
+      wtEnabled.dispatchEvent(new Event("change"));
+      return;
+    }
+
+    if (target instanceof HTMLButtonElement) {
+      if (!target.classList.contains("project-box") && !target.classList.contains("wt-choice")) return;
+      e.preventDefault();
+      if (!target.classList.contains("is-active")) {
+        target.click();
+        return;
+      }
+      form.requestSubmit();
+      return;
+    }
+
+    e.preventDefault();
+    if (target === filterInput) {
+      const top = visibleGroups(filterInput.value)[0];
+      if (top && top.main.path !== selectedGroup?.main.path) selectProject(top);
+    }
+    form.requestSubmit();
+  });
+
   // ---- submit ----------------------------------------------------------
   form.addEventListener("submit", async (e) => {
     e.preventDefault();

web/src/spawnFormEnter.test.ts

@@ -0,0 +1,258 @@
+// @vitest-environment happy-dom
+// Enter submits the draft form from any field, at any point (#97). The two
+// exceptions: a picker button that isn't yet the active choice takes the
+// Enter to *choose* it instead (the next Enter submits), and the project
+// filter must resolve to the highlighted project rather than sending
+// whatever cwd was already set.
+import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
+
+import { createSpawnForm, type SpawnFormHandle } 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",
+};
+
+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 OTHER: Project = {
+  path: "/home/user/tea/rev",
+  name: "rev",
+  is_worktree: false,
+  last_activity: "2026-08-19T10:00:00Z",
+};
+
+function stubFetch(projects: Project[]): void {
+  vi.stubGlobal(
+    "fetch",
+    vi.fn(async (input: RequestInfo | URL) => {
+      const url = String(input);
+      const body = url.includes("/api/projects")
+        ? projects
+        : url.includes("/api/names")
+          ? { names: ["amber-fox"] }
+          : url.includes("/api/branches")
+            ? []
+            : url.includes("/api/dirs")
+              ? { path: "/opt", entries: ["nomatch-zzz"], truncated: false }
+              : { hostname: "h", version: "0", home_dir: "/home/user", presets: [] };
+      return new Response(JSON.stringify(body), { status: 200 });
+    }),
+  );
+}
+
+describe("spawnForm Enter-to-submit (#97)", () => {
+  let handle: SpawnFormHandle | null = null;
+
+  beforeEach(() => {
+    vi.useFakeTimers({ now: Date.parse("2026-08-23T12:00:00Z") });
+  });
+
+  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> {
+    stubFetch(projects);
+    handle = createSpawnForm({ onSuccess() {} });
+    document.body.appendChild(handle.el);
+    await drain();
+    return handle.el;
+  }
+
+  function submitSpy(): ReturnType<typeof vi.fn> {
+    return vi.fn();
+  }
+
+  function pressEnter(el: HTMLElement): { defaultPrevented: boolean } {
+    const evt = new KeyboardEvent("keydown", { key: "Enter", bubbles: true, cancelable: true });
+    el.dispatchEvent(evt);
+    return { defaultPrevented: evt.defaultPrevented };
+  }
+
+  const box = (form: HTMLFormElement, path: string) =>
+    form.querySelector<HTMLButtonElement>(`.project-box[data-cwd="${path}"]`)!;
+
+  it("toggles the worktree checkbox on Enter instead of submitting (TUI parity)", async () => {
+    const form = await mount([MAESTRO]);
+    box(form, MAESTRO.path).click();
+    await drain();
+    const toggle = form.querySelector<HTMLInputElement>("input[name=worktree_enabled]")!;
+    expect(toggle.checked).toBe(true);
+    const spy = submitSpy();
+    form.addEventListener("submit", spy);
+
+    pressEnter(toggle);
+    expect(toggle.checked).toBe(false);
+    expect(spy).not.toHaveBeenCalled();
+
+    pressEnter(toggle);
+    expect(toggle.checked).toBe(true);
+    expect(spy).not.toHaveBeenCalled();
+  });
+
+  describe("submits immediately from ordinary fields", () => {
+    it("name field", async () => {
+      const form = await mount([MAESTRO]);
+      box(form, MAESTRO.path).click();
+      await drain();
+      const spy = submitSpy();
+      form.addEventListener("submit", spy);
+
+      pressEnter(form.querySelector<HTMLInputElement>("input[name=name]")!);
+
+      expect(spy).toHaveBeenCalledTimes(1);
+    });
+
+    it("worktree branch field", async () => {
+      const form = await mount([MAESTRO]);
+      box(form, MAESTRO.path).click();
+      await drain();
+      const spy = submitSpy();
+      form.addEventListener("submit", spy);
+
+      pressEnter(form.querySelector<HTMLInputElement>("input[name=worktree_branch]")!);
+
+      expect(spy).toHaveBeenCalledTimes(1);
+    });
+
+    it("custom command field", async () => {
+      const form = await mount([MAESTRO]);
+      box(form, MAESTRO.path).click();
+      await drain();
+      form.querySelector<HTMLButtonElement>('.cmd-tiles .tile[data-id="custom"]')!.click();
+      const raw = form.querySelector<HTMLInputElement>(".cmd-raw")!;
+      raw.value = "bash -l";
+      raw.dispatchEvent(new Event("input"));
+      const spy = submitSpy();
+      form.addEventListener("submit", spy);
+
+      pressEnter(raw);
+
+      expect(spy).toHaveBeenCalledTimes(1);
+    });
+
+    it("raw cwd field once the autocomplete dropdown is closed", async () => {
+      const form = await mount([MAESTRO]);
+      form.querySelector<HTMLButtonElement>(".project-other")!.click();
+      const raw = form.querySelector<HTMLInputElement>("input[name=cwd_raw]")!;
+      raw.value = "/opt/xyz-nothing-here";
+      raw.dispatchEvent(new Event("input"));
+      await vi.advanceTimersByTimeAsync(300);
+      const spy = submitSpy();
+      form.addEventListener("submit", spy);
+
+      pressEnter(raw);
+
+      expect(spy).toHaveBeenCalledTimes(1);
+    });
+
+    it("does not submit while the raw cwd autocomplete has a highlighted suggestion", async () => {
+      const form = await mount([MAESTRO]);
+      form.querySelector<HTMLButtonElement>(".project-other")!.click();
+      const raw = form.querySelector<HTMLInputElement>("input[name=cwd_raw]")!;
+      raw.focus();
+      raw.value = "/opt/";
+      raw.dispatchEvent(new Event("input", { bubbles: true }));
+      await vi.advanceTimersByTimeAsync(150);
+      const spy = submitSpy();
+      form.addEventListener("submit", spy);
+
+      const { defaultPrevented } = pressEnter(raw);
+
+      expect(defaultPrevented).toBe(true);
+      expect(spy).not.toHaveBeenCalled();
+      expect(raw.value).toBe("/opt/nomatch-zzz/");
+    });
+  });
+
+  describe("two-step picker: first Enter chooses, second submits", () => {
+    it("project box", async () => {
+      const form = await mount([MAESTRO]);
+      const b = box(form, MAESTRO.path);
+      b.focus();
+      const spy = submitSpy();
+      form.addEventListener("submit", spy);
+
+      const first = pressEnter(b);
+      expect(first.defaultPrevented).toBe(true);
+      expect(b.classList.contains("is-active")).toBe(true);
+      expect(spy).not.toHaveBeenCalled();
+
+      pressEnter(b);
+      expect(spy).toHaveBeenCalledTimes(1);
+    });
+
+    it("worktree choice", async () => {
+      const form = await mount([MAESTRO, WT_A]);
+      box(form, MAESTRO.path).click();
+      await drain();
+      const choice = form.querySelector<HTMLButtonElement>(`.wt-choice[data-cwd="${WT_A.path}"]`)!;
+      expect(choice.classList.contains("is-active")).toBe(false); // "+ new" is the default
+      const spy = submitSpy();
+      form.addEventListener("submit", spy);
+
+      pressEnter(choice);
+      expect(choice.classList.contains("is-active")).toBe(true);
+      expect(spy).not.toHaveBeenCalled();
+
+      pressEnter(choice);
+      expect(spy).toHaveBeenCalledTimes(1);
+    });
+  });
+
+  describe("project filter", () => {
+    it("submits with the highlighted (first matching) project, not the filter text", async () => {
+      const form = await mount([MAESTRO, OTHER]);
+      const filter = form.querySelector<HTMLInputElement>(".project-filter")!;
+      filter.value = "rev";
+      filter.dispatchEvent(new Event("input"));
+      const spy = submitSpy();
+      form.addEventListener("submit", spy);
+
+      pressEnter(filter);
+
+      expect(spy).toHaveBeenCalledTimes(1);
+      expect(box(form, OTHER.path).classList.contains("is-active")).toBe(true);
+    });
+
+    it("does not clobber an already-chosen worktree when the filter still matches it", async () => {
+      const form = await mount([MAESTRO, WT_A]);
+      box(form, MAESTRO.path).click();
+      await drain();
+      form.querySelector<HTMLButtonElement>(`.wt-choice[data-cwd="${WT_A.path}"]`)!.click();
+      await drain();
+
+      const filter = form.querySelector<HTMLInputElement>(".project-filter")!;
+      filter.value = "maestro";
+      filter.dispatchEvent(new Event("input"));
+      const spy = submitSpy();
+      form.addEventListener("submit", spy);
+
+      pressEnter(filter);
+
+      expect(spy).toHaveBeenCalledTimes(1);
+      expect(
+        form.querySelector<HTMLButtonElement>(`.wt-choice[data-cwd="${WT_A.path}"]`)!.classList.contains(
+          "is-active",
+        ),
+      ).toBe(true);
+    });
+  });
+});

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

@@ -101,7 +101,7 @@ describe("spawnForm gitroot probe debounce (#74)", () => {
   it("a keystroke burst fires exactly one probe after the quiet period", async () => {
     const { form, stub } = await mount();
 
-    form.querySelector<HTMLElement>(".project-row.project-other")!.click();
+    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));
@@ -119,7 +119,7 @@ describe("spawnForm gitroot probe debounce (#74)", () => {
   it("a stale probe answer cannot overwrite a newer input", async () => {
     const { form, stub } = await mount({ holdGitRootFor: ["/repo/old"] });
 
-    form.querySelector<HTMLElement>(".project-row.project-other")!.click();
+    form.querySelector<HTMLElement>(".project-other")!.click();
 
     // Probe for the old target, held in flight.
     typeRaw(form, "/repo/old");

web/src/spawnFormWorktree.test.ts

@@ -80,10 +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")
+      .querySelectorAll<HTMLButtonElement>(".project-box")
-      .forEach((row) => row.dataset.cwd === "/home/user/maestro" && row.click());
+      .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 () => {
@@ -118,8 +118,8 @@ describe("spawnForm worktree defaults and branch picker (#61)", () => {
     for (let i = 0; i < 40; i++) await Promise.resolve();
 
     handle.el
-      .querySelectorAll<HTMLButtonElement>(".project-row")
+      .querySelectorAll<HTMLButtonElement>(".project-box")
-      .forEach((row) => row.dataset.cwd === "/home/user/wt-91" && row.click());
+      .forEach((box) => box.dataset.cwd === "/home/user/wt-91" && box.click());
     await drain();
 
     expect(handle.el.querySelector<HTMLInputElement>("input[name=worktree_enabled]")!.checked).toBe(
@@ -134,7 +134,7 @@ describe("spawnForm worktree defaults and branch picker (#61)", () => {
 
     // 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-row.project-other")!.click();
+    form.querySelector<HTMLElement>(".project-other")!.click();
     const raw = form.querySelector<HTMLInputElement>("input[name=cwd_raw]")!;
     raw.value = "/opt/somewhere";
     raw.dispatchEvent(new Event("input"));
@@ -180,6 +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
+   one that actually names the dir) stays full. Dim the collapsed prefix. */
-   by the sidebar tree and the spawn dialog's recent-directory picker. */
+.folder-name .folder-stem {
-.folder-name .folder-stem,
-.recent-dir .folder-stem {
   color: var(--faint);
 }
 
@@ -738,7 +736,6 @@ textarea {
   display: flex;
   align-items: center;
   gap: var(--sp-2);
-  min-height: 30px;
   margin: 1px var(--sp-2);
   padding: 4px var(--sp-3);
   border-radius: var(--r-1);
@@ -789,60 +786,105 @@ textarea {
   font-weight: 400;
 }
 
+/* #120: every session card has two lines, so its row height is stable. */
+.tree-leaf.session-card {
+  flex-direction: column;
+  align-items: stretch;
+  gap: 1px;
+  /* 24px action row + 16px meta row + 1px gap + 8px vertical padding. */
+  height: 49px;
+}
+
+.card-line1 {
+  display: flex;
+  align-items: center;
+  gap: var(--sp-2);
+  min-width: 0;
+}
+
 .leaf-name {
   font-weight: 500;
   font-size: var(--fs-13);
-  flex: 0 1 auto;
+  /* Grows to push the actions to the right edge but shrinks first, so the name
-  overflow: hidden;
+     truncates before it can ever reach them — overlap is a defect (#107). */
-  text-overflow: ellipsis;
+  flex: 1 1 auto;
-  white-space: nowrap;
-}
-
-.leaf-meta {
-  font-size: var(--fs-11);
-  color: var(--muted);
-  margin-left: auto;
-  padding-left: var(--sp-2);
   min-width: 0;
-  flex: 0 1 auto;
   overflow: hidden;
   text-overflow: ellipsis;
   white-space: nowrap;
-  display: inline-flex;
+}
-  align-items: baseline;
+
+/* Line 2 — dot + duration in the state's colour, then muted fragments. The
+   state word itself is never spelled out here; the colour carries it. */
+.card-line2 {
+  display: flex;
+  align-items: center;
   gap: var(--sp-2);
-}
-
-.leaf-cmd {
-  color: var(--muted);
-  overflow: hidden;
-  text-overflow: ellipsis;
-  white-space: nowrap;
-}
-
-.leaf-badge {
   font-size: var(--fs-11);
-  letter-spacing: 0.02em;
+  min-width: 0;
-  text-transform: uppercase;
   color: var(--muted);
-  border: 1px solid var(--border);
+}
-  border-radius: var(--r-pill);
+
-  padding: 1px 8px;
+.card-line2[data-activity="active"] {
+  color: var(--live);
+}
+.card-line2[data-activity="idle"] {
+  color: var(--muted);
+}
+.card-line2[data-activity="awaiting-input"] {
+  color: var(--warn);
+}
+.card-line2[data-activity="error"] {
+  color: var(--danger);
+}
+
+.activity-dot {
+  width: 7px;
+  height: 7px;
+  border-radius: 50%;
+  background: currentColor;
   flex: 0 0 auto;
 }
 
-/* #83: the session row's blocked-work warning — an unforced kill will be
+.activity-duration {
-   refused, and the operator should see that before pressing the button. */
+  color: inherit;
-.leaf-badge.leaf-blocked {
+  flex: 0 0 auto;
-  color: var(--warn, #b45309);
-  border-color: var(--warn, #b45309);
 }
 
+/* Agent-reported detail (#112): sits after the duration, shrinks with an
+   ellipsis so it never pushes the trailing fragments off the line. */
+.activity-detail {
+  color: var(--faint);
+  /* Consume only the space left after the trailing status + command. */
+  flex: 1 1 0;
+  min-width: 0;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+/* Blocked-work / exited / command fragments recede: the ⚠ glyph already
+   signals severity and "exited" dims with the row. */
+.card-flag {
+  color: var(--faint);
+  flex: 0 0 auto;
+  min-width: 0;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+/* Status fragments stay intact. The unconditional command is the final
+   truncation target when even the complete trailing set cannot fit. */
+.leaf-cmd {
+  flex: 0 1 auto;
+}
+
+/* Actions live in line 1's flow at its right edge — never overlaid on the
+   name (#107). They reserve their width even while hover-faded. */
 .leaf-actions {
-  position: absolute;
+  flex: 0 0 auto;
-  right: var(--sp-1);
+  margin-left: auto;
-  top: 50%;
-  transform: translateY(-50%);
   display: inline-flex;
   gap: 2px;
 }
@@ -1100,9 +1142,11 @@ textarea {
 .attach-body .xterm .xterm-viewport {
   overflow-y: auto;
   scrollbar-width: none;
-  /* We drive scrollback from touchmove (see attach.ts); claim vertical pans so
+  /* Maestro drives scrollback from touchmove (see attach.ts). `pan-y` hands
-     the browser doesn't fight the handler or trigger gestures mid-scroll. */
+     the gesture to the browser, which may cancel the event stream before the
-  touch-action: pan-y;
+     terminal sees it; `none` keeps a drag inside the terminal under our
+     control while the rest of the page retains native scrolling. */
+  touch-action: none;
 }
 
 .attach-body .xterm .xterm-viewport::-webkit-scrollbar {
@@ -1286,18 +1330,33 @@ 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 {
+.worktree .wt-toggle {
-  padding: 0 6px;
+  margin: 0 calc(var(--sp-3) * -1);
-  color: var(--ink);
+  padding-left: var(--sp-3);
-  font-size: var(--fs-13);
+  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 {
@@ -1381,8 +1440,9 @@ textarea {
   color: var(--muted);
 }
 
-/* Project picker rows (#59). Worktree rows are indented under their base
+/* Working-directory picker (#95). Two steps: a grid of project boxes, then the
-   repository; rows stale beyond 7 days are dimmed but still selectable. */
+   picked project's worktree choices. Stale beyond 7 days dims but stays
+   selectable. */
 .picker {
   display: flex;
   flex-direction: column;
@@ -1397,73 +1457,155 @@ 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 {
+.wt-choice-name {
-  margin-left: var(--sp-4);
+  flex: 0 0 auto;
-}
-
-.project-row.is-stale {
-  opacity: 0.55;
-}
-
-.project-info {
-  display: flex;
-  align-items: baseline;
-  gap: var(--sp-2);
-  min-width: 0;
-}
-
-.project-name {
   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(--accent);
-  color: var(--muted);
-  overflow: hidden;
-  text-overflow: ellipsis;
-  white-space: nowrap;
 }
 
-.recent-cmd {
+.wt-choice-sub {
-  flex: 0 0 auto;
+  min-width: 0;
   font-family: var(--font-mono);
   font-size: var(--fs-12);
+  line-height: 1.35;
   color: var(--muted);
-}
+  text-align: right;
-
+  overflow-wrap: anywhere;
-.project-other .recent-dir {
-  font-family: inherit;
-  font-style: italic;
 }
 
 .picker-empty {

web/src/tree.test.ts

@@ -95,3 +95,59 @@ describe("mergeLinear", () => {
     expect(merged.path).toBe("a/b");
   });
 });
+
+describe("worktree sessions group under their repository (#99)", () => {
+  /** A session the daemon spawned into a worktree of `repo`. */
+  function worktreeSession(id: string, repo: string, wt: string): Session {
+    return { ...session(id, wt), worktree: { path: wt, base_repo: repo } } as Session;
+  }
+
+  /** Top-level folder names, after linear chains are collapsed. */
+  function topFolders(root: TreeFolder): string[] {
+    return root.children.filter((c) => c.kind === "folder").map((c) => (c as TreeFolder).name);
+  }
+
+  it("nests under the repo, not the worktree directory", () => {
+    const root = buildTree(
+      [
+        worktreeSession(
+          "a",
+          "/home/n/tea/agent-skills",
+          "/home/n/tea/agent-skills/worktrees/largo-clarinet",
+        ),
+      ],
+      "/home/n",
+      "",
+    ) as TreeFolder;
+
+    expect(topFolders(root)).toEqual(["~/tea/agent-skills"]);
+    const repo = root.children[0] as TreeFolder;
+    expect(repo.children).toHaveLength(1);
+    expect(repo.children[0].kind).toBe("leaf");
+  });
+
+  it("puts a repo's plain and worktree sessions side by side", () => {
+    const root = buildTree(
+      [
+        session("plain", "/home/n/tea/agent-skills"),
+        worktreeSession(
+          "wt",
+          "/home/n/tea/agent-skills",
+          "/home/n/tea/agent-skills/worktrees/largo-clarinet",
+        ),
+      ],
+      "/home/n",
+      "",
+    ) as TreeFolder;
+
+    expect(topFolders(root)).toEqual(["~/tea/agent-skills"]);
+    const repo = root.children[0] as TreeFolder;
+    expect(repo.children).toHaveLength(2);
+    expect(repo.children.every((c) => c.kind === "leaf")).toBe(true);
+  });
+
+  it("leaves a session without a worktree where it is", () => {
+    const root = buildTree([session("a", "/home/n/tea/arr")], "/home/n", "") as TreeFolder;
+    expect(topFolders(root)).toEqual(["~/tea/arr"]);
+  });
+});

web/src/tree.ts

@@ -2,7 +2,7 @@
 // so it can be tested directly.
 
 import type { Session } from "./types.js";
-import { abbreviateCwd, sessionCwd, sessionName } from "./types.js";
+import { abbreviateCwd, sessionName, sessionTreePath } from "./types.js";
 
 export interface TreeFolder {
   kind: "folder";
@@ -30,7 +30,9 @@ export function buildTree(sessions: Session[], home: string | undefined, filter:
   const lc = filter.trim().toLowerCase();
 
   for (const s of sessions) {
-    const cwd = sessionCwd(s);
+    // Grouped by repository, so a worktree session lands under its repo
+    // rather than in a folder of its own (#99).
+    const cwd = sessionTreePath(s);
     const dir = cwd ? abbreviateCwd(cwd, home) : "";
     if (lc) {
       const haystack = `${sessionName(s)} ${dir}`.toLowerCase();

web/src/types.ts

@@ -9,8 +9,9 @@ export type IsoTimestamp = string;
 export type SessionStatus = "Running" | "Dead";
 
 /** Daemon-inferred activity dimension, orthogonal to `SessionStatus` (NAP-340).
- * Absent on payloads from daemons that predate the field. */
+ * Absent on payloads from daemons that predate the field. `Error` is only set
-export type ActivityState = "Active" | "Idle" | "AwaitingInput";
+ * when an agent reports failure (#105); the daemon never infers it. */
+export type ActivityState = "Active" | "Idle" | "AwaitingInput" | "Error";
 
 export interface Session {
   id: Uuid;
@@ -25,8 +26,17 @@ export interface Session {
   foreground?: string | null;
   /** Inferred activity. Defaults to `Idle` on the wire when omitted. */
   activity?: ActivityState;
+  /** Short human string an agent reported alongside its state (#105) — e.g.
+   * why it is in `Error`. Shown on a sidebar card's meta line while the
+   * report is in force; cleared when the report lapses or is replaced. */
+  activity_detail?: string | null;
   /** Wall-clock of the most recent observed PTY output (NAP-340). */
   last_activity_at?: IsoTimestamp;
+  /** Wall-clock of when the session entered its current `activity` state
+   * (#102) — distinct from `last_activity_at`, which only tracks PTY output.
+   * Defaults to the Unix epoch on payloads from daemons that predate the
+   * field. */
+  activity_since?: IsoTimestamp;
   /** The pane's *current* working directory, as the daemon's activity watcher
    * observed it (`#{pane_current_path}`) — distinct from `cwd` (the spawn dir).
    * Drives the directory-based session tree. Absent until first observed. */
@@ -36,6 +46,16 @@ export interface Session {
    * without a worktree; all counts default to 0 on the wire for older
    * daemons. */
   blocked_work?: InTheWay | null;
+  /** The worktree the daemon created for this session, absent when it did not
+   * create one. `base_repo` is the repository's main checkout, which is what
+   * the session tree groups by (#99). */
+  worktree?: SessionWorktree | null;
+}
+
+/** A session's daemon-created worktree (`SessionWorktree` on the wire). */
+export interface SessionWorktree {
+  path: string;
+  base_repo: string;
 }
 
 /** One directory's immediate subdirectories (NAP-329). */
@@ -231,12 +251,23 @@ export function sessionName(s: Session): string {
 }
 
 /** The directory a session lives in: its live `current_cwd` if the daemon has
- * observed one, else the spawn `cwd`. Drives the directory-based session tree. */
+ * observed one, else the spawn `cwd`. */
 export function sessionCwd(s: Session): string | undefined {
   if (typeof s.current_cwd === "string" && s.current_cwd) return s.current_cwd;
   return s.cwd || undefined;
 }
 
+/** Where a session sits in the directory tree. A worktree session belongs to
+ * its repository, not to the worktree (#99): otherwise `~/tea/agent-skills`
+ * grows a `~/tea/agent-skills/worktrees/largo-clarinet` folder holding one
+ * session of the same name, and the repository stops being where you look for
+ * the work. `base_repo` is the main checkout — the daemon resolves it. */
+export function sessionTreePath(s: Session): string | undefined {
+  const repo = s.worktree?.base_repo;
+  if (typeof repo === "string" && repo) return repo;
+  return sessionCwd(s);
+}
+
 /** Collapse a daemon's home dir to `~`. `home` comes from `DaemonInfo.home_dir`;
  * absent/empty leaves the path untouched. Mirrors the CLI's `abbreviate_dir`. */
 export function abbreviateCwd(cwd: string, home?: string): 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);
+  });
+});