fix(maestro): deserialize unknown ActivityState variants as Idle

A newer daemon's unknown activity variant failed the whole Session
deserialization on older clients. Hand-written Deserialize maps any
unknown string to Idle; non-string values still error. (#110)

.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

crates/maestro-cli/src/sessions.rs

@@ -108,6 +108,7 @@ 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).
@@ -176,6 +177,7 @@ mod tests {
             foreground: None,
             activity: Default::default(),
             last_activity_at: chrono::Utc::now(),
+            activity_since: chrono::Utc::now(),
             current_cwd: None,
             blocked_work: None,
         }

crates/maestro-daemon/src/cli.rs

@@ -73,6 +73,9 @@ 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/session.rs

@@ -131,6 +131,11 @@ 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>>,
     sessions: Mutex<HashMap<Uuid, SessionRecord>>,
     events: broadcast::Sender<CatalogEvent>,
 }
@@ -170,6 +175,7 @@ impl SessionManager {
                 replay_bytes,
                 spawn_history: None,
                 retained: None,
+                daemon_url: std::sync::Mutex::new(None),
                 sessions: Mutex::new(HashMap::new()),
                 events,
             }),
@@ -202,6 +208,14 @@ impl SessionManager {
         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> {
@@ -278,7 +292,11 @@ 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 +318,7 @@ 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 +326,19 @@ 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();
@@ -349,6 +380,7 @@ impl SessionManager {
             foreground: None,
             activity: ActivityState::Active,
             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
@@ -565,9 +597,13 @@ 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,
                     last_activity_at: Utc::now(),
+                    activity_since: chrono::Utc::now(),
 
                     current_cwd: None,
                     blocked_work: None,
@@ -824,6 +860,12 @@ 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;

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/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() {
-        Some(Call::NewSessionPiped { env, .. }) => assert_eq!(env, &want),
-        other => panic!("expected a spawn call, got {other:?}"),
-    }
+    assert_eq!(&spawned, &want);
 }
 
 #[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

@@ -947,3 +947,101 @@ 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

@@ -27,6 +27,7 @@ fn sample(id: Uuid) -> Session {
         foreground: None,
         activity: Default::default(),
         last_activity_at: chrono::Utc::now(),
+        activity_since: chrono::Utc::now(),
         current_cwd: Some(PathBuf::from("/tmp/work/crates")),
         blocked_work: None,
     }

crates/maestro-protocol/src/lib.rs

@@ -80,6 +80,13 @@ pub struct Session {
     /// 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 +117,12 @@ 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 +131,25 @@ 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,
+        })
+    }
 }
 
 /// Optional worktree request attached to a `CreateSessionRequest`.
@@ -537,6 +568,9 @@ mod tests {
             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 +622,35 @@ 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 +660,35 @@ 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 session_round_trips() {
         let s = sample_session();

crates/maestro-testing/src/lib.rs

@@ -42,6 +42,7 @@ pub fn session(id: Uuid, cwd: &str, command: &str) -> Session {
         foreground: None,
         activity: Default::default(),
         last_activity_at: Utc::now(),
+        activity_since: chrono::Utc::now(),
         current_cwd: None,
         blocked_work: None,
     }

crates/maestro-tui/src/app.rs

@@ -175,7 +175,8 @@ impl App {
                     // Render on next loop iteration.
                 }
                 _ = tokio::time::sleep(Duration::from_millis(33)) => {
-                    // 30 Hz heartbeat.
+                    let effects = self.poll_due_probes_at(std::time::Instant::now());
+                    self.perform(effects).await;
                 }
             }
         }
@@ -439,7 +440,7 @@ impl App {
         if draft.take_name_refill() {
             effects.push(Effect::RefillNames(tab_idx));
         }
-        if let Some((seq, path)) = draft.take_gitroot_probe() {
+        if let Some((seq, path)) = draft.take_gitroot_probe(std::time::Instant::now()) {
             effects.push(Effect::ProbeGitRoot {
                 tab: tab_idx,
                 seq,
@@ -452,6 +453,26 @@ impl App {
         effects
     }
 
+    /// Fire any draft gitroot probes whose debounce window has elapsed (#74).
+    /// The 30 Hz heartbeat calls this so a burst of typing issues its one
+    /// probe even after the last keystroke.
+    fn poll_due_probes_at(&mut self, now: std::time::Instant) -> Vec<Effect> {
+        let mut effects = Vec::new();
+        for tab_idx in 0..self.state.tabs.len() {
+            let Some(PaneRef::Draft(draft)) = self.state.tabs[tab_idx].pane.as_mut() else {
+                continue;
+            };
+            if let Some((seq, path)) = draft.take_gitroot_probe(now) {
+                effects.push(Effect::ProbeGitRoot {
+                    tab: tab_idx,
+                    seq,
+                    path,
+                });
+            }
+        }
+        effects
+    }
+
     /// Populate a freshly opened draft: presets from `/api/info` (falling back
     /// to the built-ins already in place), projects from `/api/projects`, and
     /// a first name batch. Applies only if that tab still shows the draft —
@@ -1106,6 +1127,7 @@ mod tests {
                 foreground: None,
                 activity: Default::default(),
                 last_activity_at: Utc::now(),
+                activity_since: chrono::Utc::now(),
                 current_cwd: None,
                 blocked_work: None,
             }],
@@ -1328,9 +1350,7 @@ 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); // → branch mode
-        app.handle_draft_input(&InputKey::Tab); // → new-branch name
+        app.handle_draft_input(&InputKey::Tab); // → advanced disclosure (collapsed, #93)
         app.handle_draft_input(&InputKey::Tab); // → submit
 
         match app.handle_draft_input(&InputKey::Enter).as_slice() {
@@ -1347,10 +1367,11 @@ mod tests {
         }
     }
 
-    /// Editing the raw path with the worktree toggle on schedules a
-    /// `/api/gitroot` probe so the section learns its base repo (#65).
+    /// Editing the raw path schedules a `/api/gitroot` probe only once the
+    /// keystroke burst settles (#74): nothing fires inside the debounce
+    /// window; the heartbeat picks the due probe up afterwards.
     #[test]
-    fn typing_a_raw_path_schedules_a_gitroot_probe() {
+    fn typing_a_raw_path_schedules_a_debounced_gitroot_probe() {
         let mut app = make_app();
         app.dispatch(Action::NewDraftPane);
         let PaneRef::Draft(draft) = app.state.active_tab_mut().pane.as_mut().unwrap() else {
@@ -1359,13 +1380,24 @@ mod tests {
         draft.cwd_raw_visible = true;
         draft.focused_field = DraftField::CwdRaw;
 
-        let effects = app.handle_draft_input(&InputKey::char('/'));
+        // A burst of keystrokes fires nothing.
+        for c in "/opt/tooling".chars() {
+            assert!(app.handle_draft_input(&InputKey::char(c)).is_empty());
+            assert!(app.poll_due_probes_at(std::time::Instant::now()).is_empty());
+        }
+
+        // Once the quiet period passes, exactly one probe is due.
+        let due = std::time::Instant::now()
+            + std::time::Duration::from_millis(crate::draft::GITROOT_PROBE_DEBOUNCE_MS) * 10;
+        match app.poll_due_probes_at(due).as_slice() {
+            [Effect::ProbeGitRoot { tab: 0, path, .. }] => {
+                assert_eq!(path, &std::path::PathBuf::from("/opt/tooling"));
+            }
+            other => panic!("expected one ProbeGitRoot effect, got {other:?}"),
+        }
         assert!(
-            matches!(
-                effects.as_slice(),
-                [Effect::ProbeGitRoot { tab: 0, seq: 2, .. }]
-            ),
-            "{effects:?}"
+            app.poll_due_probes_at(due).is_empty(),
+            "the probe is consumed once"
         );
     }
 
@@ -1520,8 +1552,8 @@ mod tests {
             panic!("expected a draft pane");
         };
         assert_eq!(draft.command(), "aider");
-        assert_eq!(draft.rows.len(), 1);
-        assert_eq!(draft.rows[0].project.name, "maestro");
+        assert_eq!(draft.groups.len(), 1);
+        assert_eq!(draft.groups[0].main.name, "maestro");
         assert_eq!(draft.home_dir, "/home/u");
         assert_eq!(draft.name.value(), "crimson-otter");
     }
@@ -1613,6 +1645,7 @@ mod tests {
                 foreground: None,
                 activity: Default::default(),
                 last_activity_at: chrono::Utc::now(),
+                activity_since: chrono::Utc::now(),
 
                 current_cwd: None,
                 blocked_work: None,

crates/maestro-tui/src/catalog.rs

@@ -194,6 +194,7 @@ mod tests {
             foreground: None,
             activity: Default::default(),
             last_activity_at: chrono::Utc::now(),
+            activity_since: chrono::Utc::now(),
             current_cwd: None,
             blocked_work: None,
         }

crates/maestro-tui/src/sidebar.rs

@@ -1,10 +1,14 @@
-//! Sidebar widget — session list, navigation-only.
+//! Sidebar widget — session cards per `docs/SIDEBAR.md`.
 //!
-//! Status glyphs: ● attached / ○ live / ✗ dead.
+//! Line 1: status glyph (● attached / ○ live / ✗ dead) + name.
+//! Line 2: activity dot + duration in the state's colour, plus the
+//! blocked-work and exited fragments when they apply. Absent entirely when
+//! it has nothing to say.
 
 use std::collections::HashSet;
 
-use maestro_protocol::{Session, SessionStatus};
+use chrono::Utc;
+use maestro_protocol::{ActivityState, Session, SessionStatus};
 use ratatui::layout::Rect;
 use ratatui::style::{Color, Modifier, Style};
 use ratatui::text::{Line, Span};
@@ -12,6 +16,32 @@ use ratatui::widgets::{Block, Borders, Paragraph};
 use ratatui::Frame;
 use uuid::Uuid;
 
+/// Time-in-state alone earns a meta line only once the session has sat in
+/// its current activity state this long (docs/SIDEBAR.md).
+const META_LINE_AFTER_SECS: i64 = 30;
+/// A payload predating #102 defaults `activity_since` to the Unix epoch. Per
+/// docs/SIDEBAR.md such a session contributes no duration — the dot still
+/// renders — so anything implausibly old counts as "never observed" rather
+/// than a card announcing that the session has been idle for half a century.
+/// Mirrors `PLAUSIBLE_EPOCH_MS` in `web/src/activity.ts`.
+const PLAUSIBLE_SINCE_YEAR: i32 = 2010;
+const INDENT: &str = "  ";
+const META_INDENT: &str = "    ";
+/// Spawn-similar and kill, shown on the highlighted card's top-right corner.
+const ACTIONS: &str = "⧉ ✕";
+
+/// Every card sits on this background so cards read as cards against the
+/// panel; the highlighted card swaps it for the focus background instead
+/// (`Modifier::REVERSED` made the card unreadable against a background).
+const CARD_BG: Color = Color::Black;
+fn card_base(highlighted: bool) -> Style {
+    if highlighted {
+        Style::default().fg(Color::Black).bg(Color::Cyan)
+    } else {
+        Style::default().bg(CARD_BG)
+    }
+}
+
 /// Renderable sidebar state.
 #[derive(Debug, Clone)]
 pub struct Sidebar {
@@ -41,36 +71,171 @@ impl Sidebar {
         let inner = block.inner(area);
         f.render_widget(block, area);
 
+        let width = inner.width as usize;
         let mut lines: Vec<Line> = vec![Line::from(Span::styled(
             "sessions",
             Style::default().add_modifier(Modifier::BOLD),
         ))];
         for s in &self.sessions {
-            let glyph = match (s.status, self.attached.contains(&s.id)) {
-                (SessionStatus::Dead, _) => "✗",
-                (SessionStatus::Running, true) => "●",
-                (SessionStatus::Running, false) => "○",
-            };
-            let label = name_for(s);
-            // #83: a session whose worktree blocks a kill gets a warning
-            // glyph; the kill confirm names the specifics.
-            let blocked = s
-                .blocked_work
-                .filter(|b| !b.is_clear())
-                .map(|_| " ⚠")
-                .unwrap_or_default();
-            let style = if self.highlight == Some(s.id) {
-                Style::default().add_modifier(Modifier::REVERSED)
-            } else {
-                Style::default()
-            };
-            lines.push(Line::from(vec![
-                Span::raw("  "),
-                Span::styled(format!("{glyph} {label}{blocked}"), style),
-            ]));
+            let highlighted = self.highlight == Some(s.id);
+            let base = card_base(highlighted);
+            lines.push(Line::from(self.name_row(s, width)));
+            if let Some(meta) = self.meta_row(s, width) {
+                lines.push(Line::from(pad_to_width(meta, width, base)));
+            }
         }
         f.render_widget(Paragraph::new(lines), inner);
     }
+
+    fn name_row(&self, s: &Session, width: usize) -> Vec<Span<'static>> {
+        let glyph = match (s.status, self.attached.contains(&s.id)) {
+            (SessionStatus::Dead, _) => "✗",
+            (SessionStatus::Running, true) => "●",
+            (SessionStatus::Running, false) => "○",
+        };
+        let highlighted = self.highlight == Some(s.id);
+        let base = card_base(highlighted);
+        // Line-1 actions are keyboard affordances shown on the highlighted
+        // row only; they reserve their width so the name truncates with `…`
+        // before it can ever reach them (docs/SIDEBAR.md).
+        let actions_width = if highlighted {
+            ACTIONS.chars().count()
+        } else {
+            0
+        };
+        let usable = width.saturating_sub(actions_width);
+        let prefix = INDENT.chars().count() + 2;
+        // Keep one column of separation between a truncated name and the
+        // actions so the ellipsis never touches them.
+        let sep = if highlighted { 1 } else { 0 };
+        let name_budget = usable.saturating_sub(prefix + sep);
+
+        let mut spans: Vec<Span<'static>> = vec![
+            Span::styled(INDENT, base),
+            Span::styled(format!("{glyph} "), base),
+        ];
+        spans.extend(
+            fit_to_width(vec![Span::raw(name_for(s))], name_budget)
+                .into_iter()
+                .map(|sp| Span::styled(sp.content, base.patch(sp.style))),
+        );
+        let used: usize = spans.iter().map(|sp| sp.width()).sum();
+        if let Some(fill) = usable.checked_sub(used).filter(|&n| n > 0) {
+            spans.push(Span::styled(
+                " ".repeat(fill),
+                Style::default().bg(base.bg.unwrap_or(Color::Reset)),
+            ));
+        }
+        if highlighted {
+            spans.push(Span::styled(ACTIONS, base));
+        }
+        spans
+    }
+
+    /// The adaptive second line: `<dot> <duration> [<blocked work> | exited]`.
+    fn meta_row(&self, s: &Session, width: usize) -> Option<Vec<Span<'static>>> {
+        let now = Utc::now();
+        let held = held_for(s, now);
+        let held_secs = held.map(|d| d.num_seconds()).unwrap_or(0);
+        // #83: a worktree that blocks a kill is summarised here rather than
+        // on line 1; the kill confirm names the specifics.
+        let blocked = s.blocked_work.filter(|b| !b.is_clear());
+        let dead = s.status == SessionStatus::Dead;
+        let errored = s.activity == ActivityState::Error;
+        if (held.is_none() || held_secs < META_LINE_AFTER_SECS)
+            && blocked.is_none()
+            && !dead
+            && !errored
+        {
+            return None;
+        }
+        let base = card_base(self.highlight == Some(s.id));
+        let dot_style = base.patch(Style::default().fg(activity_color(s.activity)));
+        let muted = Style::default().bg(base.bg.unwrap_or(Color::Reset));
+        let mut spans = vec![
+            Span::styled(META_INDENT, base),
+            Span::styled("●", dot_style),
+        ];
+        if let Some(d) = held {
+            spans.push(Span::styled(" ", base));
+            spans.push(Span::styled(format_state_duration(d), dot_style));
+        }
+        if let Some(b) = blocked {
+            spans.push(Span::styled(format!(" ⚠ {b}"), muted));
+        }
+        if dead {
+            spans.push(Span::styled(" exited", muted));
+        }
+        Some(fit_to_width(spans, width))
+    }
+}
+
+/// ratatui colour for an [`ActivityState`], per docs/SIDEBAR.md. The state
+/// word is never spelled out — this colour carries it.
+fn activity_color(state: ActivityState) -> Color {
+    match state {
+        ActivityState::Active => Color::Green,
+        ActivityState::Idle => Color::DarkGray,
+        ActivityState::AwaitingInput => Color::Yellow,
+        ActivityState::Error => Color::Red,
+    }
+}
+
+/// docs/SIDEBAR.md duration format — floored whole seconds / minutes / hours,
+/// measured in the current activity state. No days, no rounding up.
+/// How long the session has held its current activity state, or `None` when
+/// the daemon never reported one (see [`PLAUSIBLE_SINCE_YEAR`]).
+fn held_for(s: &Session, now: chrono::DateTime<Utc>) -> Option<chrono::Duration> {
+    use chrono::Datelike;
+    if s.activity_since.year() < PLAUSIBLE_SINCE_YEAR {
+        return None;
+    }
+    Some(now - s.activity_since)
+}
+
+fn format_state_duration(elapsed: chrono::Duration) -> String {
+    let secs = elapsed.num_seconds().max(0);
+    match secs {
+        0..=59 => format!("{secs}s"),
+        60..=3599 => format!("{}m", secs / 60),
+        _ => format!("{}h", secs / 3600),
+    }
+}
+
+/// Truncate a span list to `max` columns, ending it with `…` when cut. The
+/// sidebar is narrow: card lines truncate, they never wrap.
+fn fit_to_width(spans: Vec<Span<'static>>, max: usize) -> Vec<Span<'static>> {
+    let mut out: Vec<Span<'static>> = Vec::with_capacity(spans.len());
+    let mut used = 0usize;
+    for span in spans {
+        let w = span.width();
+        if used + w <= max {
+            used += w;
+            out.push(span);
+            continue;
+        }
+        let budget = max.saturating_sub(used + 1);
+        let ellipsis = "…";
+        if budget > 0 {
+            let text: String = span.content.chars().take(budget).collect();
+            out.push(Span::styled(format!("{text}{ellipsis}"), span.style));
+        } else if used < max {
+            out.push(Span::styled(ellipsis, span.style));
+        }
+        return out;
+    }
+    out
+}
+
+/// Pad a card row out to the full sidebar width so the card background
+/// paints edge to edge rather than stopping at the last glyph.
+fn pad_to_width(mut spans: Vec<Span<'static>>, width: usize, base: Style) -> Vec<Span<'static>> {
+    let used: usize = spans.iter().map(|sp| sp.width()).sum();
+    if let Some(fill) = width.checked_sub(used).filter(|&n| n > 0) {
+        let pad_style = Style::default().bg(base.bg.unwrap_or(Color::Reset));
+        spans.push(Span::styled(" ".repeat(fill), pad_style));
+    }
+    spans
 }
 
 /// `metadata.name` if present, else the command line.
@@ -85,8 +250,10 @@ fn name_for(s: &Session) -> String {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use chrono::Utc;
+    use chrono::{DateTime, Duration};
+    use maestro_protocol::InTheWay;
     use ratatui::backend::TestBackend;
+    use ratatui::buffer::Buffer;
     use ratatui::Terminal;
     use std::collections::HashMap;
 
@@ -104,25 +271,43 @@ mod tests {
             created_at: Utc::now(),
             foreground: None,
             activity: Default::default(),
-            last_activity_at: chrono::Utc::now(),
+            last_activity_at: Utc::now(),
+            activity_since: Utc::now(),
             current_cwd: None,
             blocked_work: None,
         }
     }
 
-    fn render_to_string(sidebar: &Sidebar, w: u16, h: u16) -> String {
+    fn draw(sidebar: &Sidebar, w: u16, h: u16) -> Buffer {
         let backend = TestBackend::new(w, h);
         let mut terminal = Terminal::new(backend).unwrap();
         terminal.draw(|f| sidebar.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
+        terminal.backend().buffer().clone()
+    }
+
+    fn rows(buf: &Buffer) -> Vec<String> {
+        (0..buf.area.height)
+            .map(|y| {
+                (0..buf.area.width)
+                    .map(|x| buf[(x, y)].symbol())
+                    .collect::<String>()
+            })
+            .collect()
+    }
+
+    fn render_to_string(buf: &Buffer) -> String {
+        rows(buf).join("\n")
+    }
+
+    fn row_containing<'a>(rows: &'a [String], needle: &str) -> &'a str {
+        rows.iter()
+            .find(|l| l.contains(needle))
+            .unwrap_or_else(|| panic!("no row containing {needle:?} in {rows:#?}"))
+    }
+
+    /// Row text without the trailing space padding and right border.
+    fn content(row: &str) -> &str {
+        row.trim_end().trim_end_matches('│').trim_end()
     }
 
     #[test]
@@ -132,7 +317,7 @@ mod tests {
             highlight: None,
             attached: Default::default(),
         };
-        let rendered = render_to_string(&sb, 28, 12);
+        let rendered = render_to_string(&draw(&sb, 28, 12));
         assert!(
             rendered.contains("claude"),
             "missing session name:\n{rendered}"
@@ -151,11 +336,8 @@ mod tests {
             highlight: None,
             attached: [sid].into_iter().collect(),
         };
-        let rendered = render_to_string(&sb, 28, 6);
-        let line = rendered
-            .lines()
-            .find(|l| l.contains("claude"))
-            .expect("claude row");
+        let all = rows(&draw(&sb, 28, 6));
+        let line = row_containing(&all, "claude");
         assert!(line.contains('●'), "expected filled glyph in: {line:?}");
         assert!(
             !line.contains('○'),
@@ -172,21 +354,18 @@ mod tests {
             highlight: None,
             attached: Default::default(),
         };
-        let rendered = render_to_string(&sb, 28, 6);
-        let line = rendered
-            .lines()
-            .find(|l| l.contains("claude"))
-            .expect("claude row");
+        let buf = draw(&sb, 28, 6);
+        let all = rows(&buf);
+        let line = row_containing(&all, "claude");
         assert!(line.contains('✗'), "expected dead glyph in: {line:?}");
     }
 
-    /// #83: a session whose worktree blocks a kill carries the warning glyph;
-    /// a clear or unprobed one does not.
+    /// #83 via docs/SIDEBAR.md: blocked work lives on the meta line now, not
+    /// on the name row; a clear or unprobed worktree never warns.
     #[test]
-    fn blocked_session_gets_a_warning_glyph() {
-        use maestro_protocol::InTheWay;
-
+    fn blocked_session_warns_on_its_meta_line() {
         let mut blocked = session_named(1, "claude");
+        blocked.activity_since = Utc::now() - Duration::seconds(5);
         blocked.blocked_work = Some(InTheWay {
             unpushed_commits: 4,
             ..InTheWay::default()
@@ -199,18 +378,191 @@ mod tests {
             highlight: None,
             attached: Default::default(),
         };
-        let rendered = render_to_string(&sb, 40, 8);
-        let line = rendered
-            .lines()
-            .find(|l| l.contains("claude"))
-            .expect("blocked row");
-        assert!(line.contains('⚠'), "expected warning glyph in: {line:?}");
+        let all = rows(&draw(&sb, 40, 10));
+
+        let meta = all
+            .iter()
+            .find(|l| l.contains("⚠"))
+            .expect("blocked card must warn somewhere");
+        assert!(
+            meta.contains("4 unpushed commits"),
+            "warning must carry InTheWay's summary: {meta:?}"
+        );
+        let name_row = row_containing(&all, "claude");
+        assert!(
+            !name_row.contains('⚠'),
+            "warning moved off the name row: {name_row:?}"
+        );
         for name in ["bash", "vim"] {
-            let line = rendered
-                .lines()
-                .find(|l| l.contains(name))
-                .expect("clear row");
-            assert!(!line.contains('⚠'), "{name} must not warn: {line:?}");
+            let idx = all.iter().position(|l| l.contains(name)).unwrap();
+            assert!(
+                !all[idx + 1].contains('⚠'),
+                "{name} must not warn: {:?}",
+                all[idx + 1]
+            );
+        }
+    }
+
+    /// A freshly-active session stays one line — never an empty placeholder
+    /// row (docs/SIDEBAR.md).
+    #[test]
+    fn freshly_active_session_stays_one_line() {
+        let mut s = session_named(1, "claude");
+        s.activity_since = Utc::now() - Duration::seconds(10);
+        let sb = Sidebar {
+            sessions: vec![s],
+            highlight: None,
+            attached: Default::default(),
+        };
+        let all = rows(&draw(&sb, 28, 8));
+        assert_eq!(content(&all[0]), "sessions");
+        assert!(row_containing(&all, "claude").contains('○'));
+        assert!(
+            content(&all[2]).is_empty(),
+            "line 2 must be absent, got {:?}",
+            all[2]
+        );
+    }
+
+    /// Rule 1 of docs/SIDEBAR.md: held in state longer than 30s earns the
+    /// meta line, with the floored duration next to the dot.
+    #[test]
+    fn long_held_session_gets_a_meta_line_with_duration() {
+        let mut s = session_named(1, "claude");
+        s.activity_since = Utc::now() - Duration::seconds(90);
+        let sb = Sidebar {
+            sessions: vec![s],
+            highlight: None,
+            attached: Default::default(),
+        };
+        let all = rows(&draw(&sb, 28, 8));
+        let idx = all.iter().position(|l| l.contains("claude")).unwrap();
+        let meta = &all[idx + 1];
+        assert!(meta.contains('●'), "meta line carries the dot: {meta:?}");
+        assert!(meta.contains("1m"), "expected 1m in: {meta:?}");
+    }
+
+    #[test]
+    fn duration_format_floors_whole_units() {
+        let fmt = |secs| format_state_duration(Duration::seconds(secs));
+        assert_eq!(fmt(0), "0s");
+        assert_eq!(fmt(45), "45s");
+        assert_eq!(fmt(59), "59s");
+        assert_eq!(fmt(60), "1m");
+        assert_eq!(fmt(240), "4m");
+        assert_eq!(fmt(3599), "59m");
+        assert_eq!(fmt(3600), "1h");
+        assert_eq!(fmt(7200), "2h");
+    }
+
+    /// The dot and duration carry the activity state's colour; the state word
+    /// is never spelled out (docs/SIDEBAR.md colour table).
+    #[test]
+    fn meta_line_dot_uses_the_contract_colour_per_state() {
+        for (state, expected) in [
+            (ActivityState::Active, Color::Green),
+            (ActivityState::Idle, Color::DarkGray),
+            (ActivityState::AwaitingInput, Color::Yellow),
+            (ActivityState::Error, Color::Red),
+        ] {
+            let mut s = session_named(1, "claude");
+            s.activity = state;
+            s.activity_since = Utc::now() - Duration::seconds(120);
+            let sb = Sidebar {
+                sessions: vec![s],
+                highlight: None,
+                attached: Default::default(),
+            };
+            let buf = draw(&sb, 28, 8);
+            let found = (0..buf.area.height)
+                .any(|y| (0..buf.area.width).any(|x| buf[(x, y)].style().fg == Some(expected)));
+            assert!(found, "expected some cell in fg {expected:?} for {state:?}");
+        }
+    }
+
+    /// Rule 3 of docs/SIDEBAR.md: a dead session always gets a meta line,
+    /// even freshly dead, with the muted `exited` fragment.
+    #[test]
+    fn dead_session_shows_exited_on_its_meta_line() {
+        let mut s = session_named(1, "claude");
+        s.status = SessionStatus::Dead;
+        s.activity_since = Utc::now() - Duration::seconds(5);
+        let sb = Sidebar {
+            sessions: vec![s],
+            highlight: None,
+            attached: Default::default(),
+        };
+        let all = rows(&draw(&sb, 28, 8));
+        let idx = all.iter().position(|l| l.contains("claude")).unwrap();
+        assert!(
+            all[idx + 1].contains("exited"),
+            "expected exited fragment in: {:?}",
+            all[idx + 1]
+        );
+    }
+
+    /// The sidebar is narrow: the meta line truncates with `…` and never
+    /// wraps onto a third row (docs/SIDEBAR.md).
+    #[test]
+    fn meta_line_truncates_instead_of_wrapping() {
+        let mut s = session_named(1, "claude");
+        s.activity_since = Utc::now() - Duration::seconds(5);
+        s.blocked_work = Some(InTheWay {
+            uncommitted_files: 120,
+            ..InTheWay::default()
+        });
+        let sb = Sidebar {
+            sessions: vec![s],
+            highlight: None,
+            attached: Default::default(),
+        };
+        let all = rows(&draw(&sb, 28, 8));
+        let idx = all.iter().position(|l| l.contains("claude")).unwrap();
+        let meta = content(&all[idx + 1]);
+        assert!(
+            meta.trim_end().ends_with('…'),
+            "truncated meta line must end with …: {meta:?}"
+        );
+        assert!(
+            content(&all[idx + 2]).trim().is_empty(),
+            "meta line must not wrap: {:?}",
+            all[idx + 2]
+        );
+    }
+
+    /// docs/SIDEBAR.md: a payload predating #102 carries an epoch
+    /// `activity_since` and so contributes no duration — a card must not claim
+    /// the session has been idle since 1970. The dot still renders when some
+    /// other trigger puts line 2 on screen.
+    #[test]
+    fn epoch_activity_since_renders_no_duration() {
+        let mut legacy = session_named(1, "claude");
+        legacy.activity_since = DateTime::from_timestamp(0, 0).unwrap();
+        legacy.status = SessionStatus::Dead;
+        let sb = Sidebar {
+            sessions: vec![legacy],
+            highlight: None,
+            attached: Default::default(),
+        };
+        let rendered = render_to_string(&draw(&sb, 40, 8));
+        assert!(
+            rendered.contains("exited"),
+            "dead session must still show line 2:\n{rendered}"
+        );
+        assert!(
+            !rendered.contains('h') || !rendered.contains("● "),
+            "no duration may follow the dot for an epoch stamp:\n{rendered}"
+        );
+        for line in rendered.lines().filter(|l| l.contains('●')) {
+            assert!(
+                !line
+                    .split('●')
+                    .nth(1)
+                    .unwrap_or("")
+                    .trim_start()
+                    .starts_with(char::is_numeric),
+                "duration rendered from an epoch stamp: {line:?}"
+            );
         }
     }
 
@@ -227,8 +579,8 @@ mod tests {
             created_at: Utc::now(),
             foreground: None,
             activity: Default::default(),
-            last_activity_at: chrono::Utc::now(),
-
+            last_activity_at: Utc::now(),
+            activity_since: Utc::now(),
             current_cwd: None,
             blocked_work: None,
         };
@@ -237,10 +589,150 @@ mod tests {
             highlight: None,
             attached: Default::default(),
         };
-        let rendered = render_to_string(&sb, 28, 6);
+        let rendered = render_to_string(&draw(&sb, 28, 6));
         assert!(
             rendered.contains("vim"),
             "missing fallback command name:\n{rendered}"
         );
     }
+
+    /// Reversed video makes a card unreadable against a background; cards
+    /// use explicit backgrounds instead (docs/SIDEBAR.md, #108).
+    #[test]
+    fn no_cell_is_ever_reversed() {
+        let mut highlighted = session_named(1, "claude");
+        highlighted.activity_since = Utc::now() - Duration::seconds(120);
+        let sb = Sidebar {
+            sessions: vec![highlighted],
+            highlight: Some(Uuid::from_u128(1)),
+            attached: Default::default(),
+        };
+        let buf = draw(&sb, 28, 8);
+        for y in 0..buf.area.height {
+            for x in 0..buf.area.width {
+                assert!(
+                    !buf[(x, y)]
+                        .style()
+                        .add_modifier
+                        .contains(Modifier::REVERSED),
+                    "reversed video at ({x},{y})"
+                );
+            }
+        }
+    }
+
+    /// The highlighted card gets the focus background; every other card gets
+    /// a card background distinct from the panel's default.
+    #[test]
+    fn cards_use_explicit_backgrounds_with_a_distinct_focus_background() {
+        let one = session_named(1, "claude");
+        let two = session_named(2, "bash");
+        let sb = Sidebar {
+            sessions: vec![one, two],
+            highlight: Some(Uuid::from_u128(1)),
+            attached: Default::default(),
+        };
+        let buf = draw(&sb, 28, 8);
+        let all = rows(&buf);
+        let claude_y = all.iter().position(|l| l.contains("claude")).unwrap();
+        let bash_y = all.iter().position(|l| l.contains("bash")).unwrap();
+
+        assert_eq!(
+            buf[(0, claude_y as u16)].style().bg,
+            Some(Color::Cyan),
+            "focused card must sit on the focus background"
+        );
+        assert_eq!(
+            buf[(0, claude_y as u16)].style().fg,
+            Some(Color::Black),
+            "focused card text must stay readable on cyan"
+        );
+        assert_eq!(
+            buf[(0, bash_y as u16)].style().bg,
+            Some(Color::Black),
+            "unfocused cards must still have a card background"
+        );
+        // The panel itself (header row) stays on the terminal default.
+        assert!(
+            matches!(buf[(0, 0)].style().bg, None | Some(Color::Reset)),
+            "panel must keep the terminal default background"
+        );
+    }
+
+    /// The card background paints the full card width, not just the glyphs.
+    #[test]
+    fn card_background_covers_the_full_card_width() {
+        let s = session_named(1, "claude");
+        let sb = Sidebar {
+            sessions: vec![s],
+            highlight: None,
+            attached: Default::default(),
+        };
+        let buf = draw(&sb, 28, 8);
+        let y = buf.content.iter().position(|c| c.symbol() == "c").unwrap() as u16 / buf.area.width;
+        for x in 0..27 {
+            assert_eq!(
+                buf[(x, y)].style().bg,
+                Some(Color::Black),
+                "gap in card background at col {x}"
+            );
+        }
+    }
+
+    /// Line 1's actions live on the highlighted row's top-right corner.
+    #[test]
+    fn highlighted_row_anchors_the_actions_top_right() {
+        let sb = Sidebar {
+            sessions: vec![session_named(1, "claude")],
+            highlight: Some(Uuid::from_u128(1)),
+            attached: Default::default(),
+        };
+        let all = rows(&draw(&sb, 28, 8));
+        let line = content(row_containing(&all, "claude"));
+        assert!(
+            line.ends_with("⧉ ✕"),
+            "actions must sit at the right edge: {line:?}"
+        );
+    }
+
+    #[test]
+    fn unhighlighted_rows_show_no_actions() {
+        let one = session_named(1, "claude");
+        let two = session_named(2, "bash");
+        let sb = Sidebar {
+            sessions: vec![one, two],
+            highlight: Some(Uuid::from_u128(1)),
+            attached: Default::default(),
+        };
+        let all = rows(&draw(&sb, 28, 8));
+        let line = row_containing(&all, "bash");
+        assert!(
+            !line.contains('⧉') && !line.contains('✕'),
+            "actions are highlight-only: {line:?}"
+        );
+    }
+
+    /// The name truncates with `…` before it can ever reach the reserved
+    /// action width (docs/SIDEBAR.md — overlap is a defect).
+    #[test]
+    fn name_truncates_before_reaching_the_actions() {
+        let mut s = session_named(1, "claude");
+        if let Some(serde_json::Value::String(name)) = s.metadata.get_mut("name") {
+            *name = "an-unreasonably-long-session-name".into();
+        }
+        let sb = Sidebar {
+            sessions: vec![s],
+            highlight: Some(Uuid::from_u128(1)),
+            attached: Default::default(),
+        };
+        let all = rows(&draw(&sb, 28, 8));
+        let line = row_containing(&all, "an-unreasonably");
+        let name_end = line.find('…').expect("name must truncate with …");
+        let actions_start = line.find('⧉').expect("actions must still render");
+        assert!(name_end < actions_start, "name overlaps actions: {line:?}");
+        assert!(
+            line.split_at(actions_start).0.ends_with(' '),
+            "no gap before the actions: {line:?}"
+        );
+    }
 }

docs/SIDEBAR.md

@@ -0,0 +1,104 @@
+# 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 has **line 1** always and **line 2** only when line 2 has something to
+say.
+
+## Line 1 — name + actions
+
+- Left: the session name — `metadata.name` if present, else the command line
+  (same fallback both clients already use).
+- Right: two actions anchored to the top-right corner: **spawn similar**
+  (`⧉`) and **kill** (`✕`). In the TUI these are keyboard affordances shown on
+  the highlighted row; in the web they are buttons. The glyphs are shared so
+  muscle memory transfers.
+- Actions reserve their fixed width; the name truncates with `…` before it can
+  ever reach them. **Overlap between the name and the actions is a defect** —
+  that overlap is what started this milestone.
+
+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)
+
+Rendered only when at least one of these holds:
+
+1. The session has been held in its current activity state longer than
+   **30 seconds** (`activity_since` from #102). A freshly-active session
+   stays one line.
+2. Its worktree holds blocked work: `blocked_work` is `Some` and not clear
+   (`InTheWay::is_clear()`), rendered in `formatInTheWay`'s phrasing on web
+   and as `⚠ <summary>` on the TUI.
+3. It has exited: `status == Dead`.
+4. An agent-reported state (#105) of `Error` is in force (see Precedence).
+
+Otherwise line 2 is absent — never an empty placeholder row.
+
+When present, line 2 reads left to right:
+
+```
+<dot> <duration> [<blocked work> | exited] [<command>]
+```
+
+`<dot>` is a single filled glyph (`●` on both clients) carrying the activity
+state's colour, and `<duration>` follows in the same colour. 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
+and duration are unconditional parts of line 2; the bracketed fragments appear
+only when their trigger holds. A payload that predates #102 (no usable
+`activity_since`) contributes no duration — the dot still renders.
+
+`<command>` is optional and muted: the session's command line, shown only when
+the rendered name came from `metadata.name` and differs from the command (the
+web has always surfaced this; the TUI may omit it).
+
+## Colour per activity state
+
+The state word is never spelled out — the colour carries it.
+
+| Activity state   | Web token | ratatui colour    |
+| ---------------- | --------- | ----------------- |
+| `Active`         | `--live`  | `Color::Green`    |
+| `Idle`           | `--muted` | `Color::DarkGray` |
+| `AwaitingInput`  | `--warn`  | `Color::Yellow`   |
+| `Error`          | `--danger`| `Color::Red`      |
+
+Web tokens resolve per theme automatically (`styles.css` defines dark, light,
+and `prefers-color-scheme` variants for each). The TUI uses the plain ratatui
+named colours above; do not introduce RGB values or a new palette module for
+this.
+
+The duration text inherits its state's colour; the blocked-work, exited and
+command fragments use the muted colour (`--faint` / default style), 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
+the TTL the report carries; when the TTL expires, inference resumes. Clients
+never blend the two: whichever source is in force supplies both the colour and
+the clock for `activity_since`.
+
+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.

web/src/activity.test.ts

@@ -0,0 +1,101 @@
+import { describe, expect, it } from "vitest";
+
+import {
+  activityColorSlug,
+  activityDurationLabel,
+  activityHeldMs,
+  showsMetaLine,
+} from "./activity.js";
+import type { Session } from "./types.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");
+  });
+});
+
+function session(overrides: Partial<Session>): Session {
+  return {
+    id: "11111111-2222-3333-4444-555555555555",
+    cwd: "/home/naps/tea/maestro",
+    command: "claude",
+    env: {},
+    metadata: {},
+    status: "Running",
+    created_at: "2026-08-24T10:00:00Z",
+    activity: "Active",
+    ...overrides,
+  };
+}
+
+describe("showsMetaLine", () => {
+  const fresh = new Date(Date.now() - 10_000).toISOString();
+
+  it("stays hidden for a freshly-active session", () => {
+    expect(showsMetaLine(session({ activity_since: fresh }))).toBe(false);
+  });
+
+  it("appears once the state has been held past 30 seconds", () => {
+    const held = new Date(Date.now() - 31_000).toISOString();
+    expect(showsMetaLine(session({ activity_since: held }))).toBe(true);
+  });
+
+  it("appears for blocked work, exited sessions and reported errors", () => {
+    expect(
+      showsMetaLine(session({ activity_since: fresh, blocked_work: { uncommitted_files: 1 } })),
+    ).toBe(true);
+    expect(showsMetaLine(session({ activity_since: fresh, status: "Dead" }))).toBe(true);
+    expect(showsMetaLine(session({ activity_since: fresh, activity: "Error" }))).toBe(true);
+  });
+
+  it("needs no activity timestamp when another trigger holds", () => {
+    expect(showsMetaLine(session({ activity_since: undefined, status: "Dead" }))).toBe(true);
+  });
+});

web/src/activity.ts

@@ -0,0 +1,56 @@
+// 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, Session } from "./types.js";
+import { sessionBlockers } from "./types.js";
+
+/** A state held shorter than this keeps the card to one line (contract rule 1). */
+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";
+  }
+}
+
+/** Line 2 renders only when at least one contract trigger holds. */
+export function showsMetaLine(s: Session, now: number = Date.now()): boolean {
+  const held = activityHeldMs(s.activity_since, now);
+  return (
+    (held !== null && held >= META_LINE_MIN_HOLD_MS) ||
+    sessionBlockers(s) !== null ||
+    s.status === "Dead" ||
+    s.activity === "Error"
+  );
+}

web/src/catalog.test.ts

@@ -104,3 +104,122 @@ describe("blocked-work indicator (#83)", () => {
     expect(confirmations).toEqual(['Kill session "claude"?']);
   });
 });
+
+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("stays a single line while freshly active", () => {
+    const s = session({
+      id: "aaaaaaaa-0000-0000-0000-000000000011",
+      activity: "Active",
+      activity_since: ago(5_000),
+    });
+    const el = renderSidebar(storeWith([s])).el;
+    expect(rowFor(el, s.id)?.querySelector(".card-line2")).toBeNull();
+  });
+
+  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("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 +4,7 @@ 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, showsMetaLine } from "./activity.js";
 import type { TreeNode } from "./tree.js";
 import { buildTree } from "./tree.js";
 import { createThemeToggle } from "./theme.js";
@@ -17,6 +18,41 @@ 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 name = sessionName(s);
+  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 ? activityDurationLabel(held) : null;
+  // The directory is the enclosing folder, so only surface the command — and
+  // only when it isn't already what the name shows.
+  const showCmd = s.command !== name;
+
+  const fragments = [
+    `<span class="activity-dot" role="img" title="${escapeHtml(stateWord)}" aria-label="${escapeHtml(stateWord)}"></span>`,
+    duration ? `<span class="activity-duration">${duration}</span>` : "",
+    blockers
+      ? `<span class="card-flag leaf-blocked" title="Kill will be refused unless forced">⚠ ${escapeHtml(formatInTheWay(blockers))}</span>`
+      : "",
+    dead ? `<span class="card-flag">exited</span>` : "",
+    showCmd
+      ? `<span class="card-flag leaf-cmd" title="${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 +88,34 @@ 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}, ${running ? "running" : "exited"}`);
-  // The directory is the enclosing folder, so only surface the command — and
-  // only when it isn't already what the name shows.
-  const showCmd = s.command !== name;
-  // #83: warn on the row itself, in `formatInTheWay`'s shared phrasing, so
-  // "this will be refused" is visible before the kill is attempted.
-  const blockers = sessionBlockers(s);
+  const stateWord =
+    STATE_WORDS[activityColorSlug(s.activity ?? "Idle")] ?? STATE_WORDS.idle;
+  row.setAttribute(
+    "aria-label",
+    `${name}, ${running ? "running" : "exited"}, ${stateWord}`,
+  );
+  // docs/SIDEBAR.md line 1: name + top-right actions in the same flow line —
+  // the actions reserve their width, so the name truncates before it can ever
+  // reach them. Line 2 renders only when a contract trigger holds.
+  const showMeta = showsMetaLine(s, now);
   row.innerHTML = `
-    <span class="leaf-name">${escapeHtml(name)}</span>
-    ${showCmd ? `<span class="leaf-meta"><span class="leaf-cmd">${escapeHtml(s.command)}</span></span>` : ""}
-    ${running ? "" : `<span class="leaf-badge">exited</span>`}
-    ${blockers ? `<span class="leaf-badge leaf-blocked" title="Kill will be refused unless forced">⚠ ${escapeHtml(formatInTheWay(blockers))}</span>` : ""}
-    <span class="leaf-actions">
-      <button class="leaf-act leaf-clone" type="button" title="Spawn similar" aria-label="Spawn similar to ${escapeHtml(name)}">⧉</button>
-      <button class="leaf-act leaf-kill" type="button" title="Kill session" aria-label="Kill ${escapeHtml(name)}">✕</button>
+    <span class="card-line1">
+      <span class="leaf-name">${escapeHtml(name)}</span>
+      <span class="leaf-actions">
+        <button class="leaf-act leaf-clone" type="button" title="Spawn similar" aria-label="Spawn similar to ${escapeHtml(name)}">⧉</button>
+        <button class="leaf-act leaf-kill" type="button" title="Kill session" aria-label="Kill ${escapeHtml(name)}">✕</button>
+      </span>
     </span>
+    ${showMeta ? 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>
-    ${opts.cmd !== opts.name ? `<span class="leaf-meta"><span class="leaf-cmd">${opts.cmd}</span></span>` : ""}
-    ${opts.status === "dead" ? `<span class="leaf-badge">exited</span>` : ""}
-    <span class="leaf-actions">
-      <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" aria-label="Kill ${opts.name}">✕</button>
-    </span>`;
+    <span class="card-line1">
+      <span class="leaf-name">${opts.name}</span>
+      <span class="leaf-actions">
+        <button class="leaf-act leaf-clone" type="button" title="Spawn similar">⧉</button>
+        <button class="leaf-act leaf-kill" type="button" title="Kill session">✕</button>
+      </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(
-        "attach-state · open",
-        h("span", "attach-state", "live"),
-      ),
+      specimen("card-line2 · active", activeLine),
+      specimen("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({ name: "scratch", cmd: "bash", status: "dead", indent: 1 }),
+      leafRow({
+        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 {
-    const tab = activeTab(layout);
+  function openDraft(seed?: Partial<Draft>, opts?: { newTab?: boolean }): void {
     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[] {
-  return [...form.querySelectorAll<HTMLButtonElement>(".project-row:not(.project-other)")].map(
-    (r) => r.dataset.cwd ?? "",
+function boxPaths(form: HTMLFormElement): string[] {
+  return [...form.querySelectorAll<HTMLButtonElement>(".project-box")].map(
+    (b) => b.dataset.cwd ?? "",
   );
 }
 
-describe("spawnForm project picker", () => {
+describe("spawnForm project picker (#95: boxes, full paths, mains only)", () => {
   let handle: SpawnFormHandle | null = null;
 
   beforeEach(() => {
@@ -65,7 +65,7 @@ describe("spawnForm project picker", () => {
     return handle;
   }
 
-  it("renders one row per project, fresh before stale", async () => {
+  it("renders one box per project, fresh before stale", async () => {
     const fresh = project({ name: "fresh", path: "/home/user/fresh", last_activity: NOW });
     const stale = project({
       name: "stale",
@@ -73,40 +73,56 @@ describe("spawnForm project picker", () => {
       last_activity: "2026-01-01T00:00:00Z",
     });
     const form = (await mount([stale, fresh])).el;
-    expect(rowPaths(form)).toEqual(["/home/user/fresh", "/home/user/stale"]);
-    const rows = [...form.querySelectorAll<HTMLButtonElement>(".project-row")];
-    expect(rows[1].classList.contains("is-stale")).toBe(true);
-    expect(rows[0].classList.contains("is-stale")).toBe(false);
+    expect(boxPaths(form)).toEqual(["/home/user/fresh", "/home/user/stale"]);
+    const boxes = [...form.querySelectorAll<HTMLButtonElement>(".project-box")];
+    expect(boxes[1].classList.contains("is-stale")).toBe(true);
+    expect(boxes[0].classList.contains("is-stale")).toBe(false);
   });
 
-  it("nests worktrees under their base repository", async () => {
+  it("shows the name as the primary line and the full path unabbreviated", async () => {
+    const p = project({ name: "nixos-config", path: "/home/user/tea/nixos-config" });
+    const form = (await mount([p])).el;
+    const box = form.querySelector<HTMLButtonElement>(".project-box")!;
+    expect(box.querySelector(".project-name")!.textContent).toBe("nixos-config");
+    // Not `~/t/nixos-config`: the abbreviation hid what distinguishes two
+    // projects sharing a basename (#95).
+    expect(box.querySelector(".project-path")!.textContent).toBe("/home/user/tea/nixos-config");
+  });
+
+  it("lists only main checkouts as boxes — worktrees belong to step two", async () => {
     const main = project({ name: "maestro", path: "/home/user/maestro" });
     const wt = project({
       name: "wt",
-      path: "/elsewhere/wt",
+      path: "/home/user/maestro/worktrees/wt",
       is_worktree: true,
       base_repo: main.path,
     });
     const form = (await mount([wt, main])).el;
-    expect(rowPaths(form)).toEqual(["/home/user/maestro", "/elsewhere/wt"]);
-    const [mainRow, wtRow] = [
-      ...form.querySelectorAll(".project-row:not(.project-other)"),
-    ];
-    expect(wtRow.classList.contains("is-worktree")).toBe(true);
-    expect(mainRow.classList.contains("is-worktree")).toBe(false);
+    expect(boxPaths(form)).toEqual(["/home/user/maestro"]);
+    expect(form.querySelector(".project-box.is-worktree")).toBeNull();
   });
 
-  it("filters rows as the operator types", async () => {
+  it("filters boxes as the operator types, keeping a repo its worktree matched", async () => {
     const a = project({ name: "maestro", path: "/home/user/maestro" });
     const b = project({ name: "tea", path: "/home/user/work/tea" });
-    const form = (await mount([a, b])).el;
+    const wt = project({
+      name: "bulgarians",
+      path: "/home/user/maestro/worktrees/bulgarians",
+      is_worktree: true,
+      base_repo: a.path,
+    });
+    const form = (await mount([a, b, wt])).el;
     const filter = form.querySelector<HTMLInputElement>(".project-filter")!;
     filter.value = "tea";
     filter.dispatchEvent(new Event("input"));
-    expect(rowPaths(form)).toEqual(["/home/user/work/tea"]);
+    expect(boxPaths(form)).toEqual(["/home/user/work/tea"]);
+    // A query that only matches a worktree still surfaces its repository box.
+    filter.value = "bulgarians";
+    filter.dispatchEvent(new Event("input"));
+    expect(boxPaths(form)).toEqual(["/home/user/maestro"]);
     filter.value = "zzz";
     filter.dispatchEvent(new Event("input"));
-    expect(rowPaths(form)).toEqual([]);
+    expect(boxPaths(form)).toEqual([]);
     expect(form.querySelector(".picker-empty")).toBeTruthy();
   });
 
@@ -135,17 +151,17 @@ describe("spawnForm project picker", () => {
     for (let i = 0; i < 20; i++) await Promise.resolve();
     onChange.mockClear();
 
-    const row = form.querySelector<HTMLButtonElement>(".project-row")!;
-    row.click();
+    const box = form.querySelector<HTMLButtonElement>(".project-box")!;
+    box.click();
 
     const values = form.querySelector<HTMLInputElement>("input[name=name]")!.value;
     const last = onChange.mock.lastCall![0];
     expect(last.cwd).toBe("/home/user/maestro");
     expect(last.command).toBe("claude");
     expect(values).toBeTruthy();
-    // The raw input stays hidden — the picked row is the source of truth.
+    // The raw input stays hidden — the picked box is the source of truth.
     expect((form.querySelector(".cwd-raw-wrap") as HTMLElement).hidden).toBe(true);
-    expect(row.classList.contains("is-active")).toBe(true);
+    expect(box.classList.contains("is-active")).toBe(true);
   });
 
   it("keeps an 'Other directory…' escape hatch that reveals the raw input", async () => {

web/src/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). */
@@ -94,6 +94,11 @@ export const FALLBACK_PRESETS: SpawnPreset[] = [
   { id: "custom", label: "Custom…", command: "" },
 ];
 
+/** Quiet period after raw-path typing before `/api/gitroot` fires (#74).
+ * Must stay equal to `GITROOT_PROBE_DEBOUNCE_MS` in
+ * crates/maestro-tui/src/draft.rs so both clients debounce alike. */
+const GITROOT_PROBE_DEBOUNCE_MS = 250;
+
 export interface SpawnFormHandle {
   el: HTMLFormElement;
   /** Remove global listeners (dir autocomplete) — call when unmounting. */
@@ -125,15 +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">
@@ -142,33 +152,38 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
       </div>
     </div>
     <fieldset class="worktree">
-      <legend>
+      <button type="button" class="tree-folder-header wt-toggle" aria-expanded="false">
+        <span class="chevron">▾</span>
+        <span class="folder-name">Advanced options</span>
+        <span class="wt-summary"></span>
+      </button>
+      <div class="wt-collapsible" hidden>
         <label class="row-inline">
           <input type="checkbox" name="worktree_enabled" />
           Create git worktree
         </label>
-      </legend>
-      <p class="wt-hint" hidden></p>
-      <div class="wt-body" hidden>
-        <p class="wt-repo"></p>
-        <div class="wt-mode" role="radiogroup" aria-label="Branch source">
-          <label class="row-inline">
-            <input type="radio" name="worktree_branch_mode" value="new" />
-            New branch
+        <p class="wt-hint" hidden></p>
+        <div class="wt-body" hidden>
+          <p class="wt-repo"></p>
+          <div class="wt-mode" role="radiogroup" aria-label="Branch source">
+            <label class="row-inline">
+              <input type="radio" name="worktree_branch_mode" value="new" />
+              New branch
+            </label>
+            <label class="row-inline">
+              <input type="radio" name="worktree_branch_mode" value="existing" />
+              Existing branch
+            </label>
+          </div>
+          <label class="wt-new-wrap">
+            New branch name
+            <input name="worktree_branch" type="text" placeholder="feat/foo" autocomplete="off" />
           </label>
-          <label class="row-inline">
-            <input type="radio" name="worktree_branch_mode" value="existing" />
-            Existing branch
+          <label class="wt-exist-wrap" hidden>
+            Pick a branch
+            <select class="branch-select"></select>
           </label>
         </div>
-        <label class="wt-new-wrap">
-          Branch
-          <input name="worktree_branch" type="text" placeholder="feat/foo" autocomplete="off" />
-        </label>
-        <label class="wt-exist-wrap" hidden>
-          Branch
-          <select class="branch-select"></select>
-        </label>
       </div>
     </fieldset>
     <p class="form-error" role="alert" aria-live="polite"></p>
@@ -182,11 +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;
@@ -337,6 +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) {
@@ -345,13 +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();
     }
@@ -367,7 +407,11 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
       if (info.presets?.length) {
         presets = info.presets;
         renderCommandTiles();
-        applyInitialCommand();
+        if (commandTouched) {
+          reapplyActiveTile();
+        } else {
+          applyInitialCommand();
+        }
       }
     })
     .catch(() => {
@@ -394,12 +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();
@@ -413,55 +481,98 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
     cwd = cwdRaw.value.trim();
     branchCache = null;
     emit();
-    if (wtEnabled.checked) probeGitRoot();
+    if (wtEnabled.checked) scheduleGitRootProbe();
   });
 
-  function markActiveProject(activeCwd: string | null): void {
-    for (const row of recentsEl.querySelectorAll(".project-row")) {
-      row.classList.toggle(
-        "is-active",
-        (row as HTMLElement).dataset.cwd === activeCwd,
-      );
+  /** Every worktree of a group, including the group's own box when the scan
+   * found no main checkout to nest it under. */
+  function worktreesOf(group: ProjectGroup): Project[] {
+    return [group.main, ...group.worktrees].filter((p) => p.is_worktree);
+  }
+
+  function markActiveBox(): void {
+    const active = selectedGroup?.main.path ?? null;
+    for (const box of projectsEl.querySelectorAll(".project-box")) {
+      box.classList.toggle("is-active", (box as HTMLElement).dataset.cwd === active);
     }
   }
 
-  function selectProject(project: Project): void {
-    cwd = project.path;
+  function markActiveChoice(): void {
+    for (const btn of wtChoices.querySelectorAll(".wt-choice")) {
+      const el = btn as HTMLElement;
+      const value = el.dataset.kind === "new" ? "new" : (el.dataset.cwd ?? "");
+      el.classList.toggle("is-active", value === worktreeChoice);
+    }
+  }
+
+  function clearProjectSelection(): void {
+    selectedGroup = null;
+    worktreeChoice = "new";
+    wtChoices.replaceChildren();
+    wtStep.hidden = true;
+    markActiveBox();
+  }
+
+  function selectProject(group: ProjectGroup): void {
+    selectedGroup = group;
     cwdRawWrap.hidden = true;
-    markActiveProject(project.path);
-    // The scan already knows this directory is inside a repo (#61): the
-    // toggle defaults back on and no /api/gitroot round trip is needed.
-    wtEnabled.checked = true;
-    applyProjectRepo(project.base_repo ?? project.path);
+    renderWorktreeChoices(group);
+    markActiveBox();
+    // Rule 4: a box that is itself a linked worktree defaults to running there.
+    applyWorktreeChoice(group.main.is_worktree ? group.main.path : "new");
+  }
+
+  function applyWorktreeChoice(choice: WorktreeChoice): void {
+    const group = selectedGroup;
+    if (!group) return;
+    const target =
+      choice === "new" ? group.main : worktreesOf(group).find((p) => p.path === choice);
+    if (!target) return;
+    worktreeChoice = choice;
+    cwd = target.path;
+    branchCache = null;
+    markActiveChoice();
+    if (choice === "new") {
+      wtEnabled.checked = true;
+      updateWtSummary();
+      applyProjectRepo(group.main.base_repo ?? group.main.path);
+    } else {
+      wtEnabled.checked = false;
+      updateWtSummary();
+      inferredBaseRepo = null;
+      wtBody.hidden = true;
+      wtHint.hidden = true;
+    }
     emit();
-    // Picking a project pre-selects the command it was last used with.
-    const match = presets.find((p) => p.command === project.last_command && p.command !== "");
+    // The chosen directory pre-selects the command it was last used with.
+    const match = presets.find((p) => p.command === target.last_command && p.command !== "");
     if (match) selectPreset(match.id);
   }
 
-  let discovered: Project[] = []; // daemon snapshot, daemon-sorted
+  /** 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();
-    const sorted = sortProjects(filterProjects(discovered, filterInput.value), new Date());
-    for (const group of groupProjects(sorted)) {
-      recentsEl.appendChild(projectRow(group.main));
-      for (const wt of group.worktrees) recentsEl.appendChild(projectRow(wt));
-    }
-    if (discovered.length > 0 && sorted.length === 0) {
+    projectsEl.replaceChildren();
+    groups = groupProjects(sortProjects(discovered, new Date()));
+    const visible = visibleGroups(filterInput.value);
+    for (const group of visible) projectsEl.appendChild(projectBox(group));
+    if (discovered.length > 0 && visible.length === 0) {
       const empty = document.createElement("p");
       empty.className = "picker-empty";
       empty.textContent = "No projects match.";
-      recentsEl.appendChild(empty);
+      projectsEl.appendChild(empty);
     }
-    recentsEl.appendChild(otherDirRow());
-    markActiveProject(cwdRawWrap.hidden ? cwd : null);
+    markActiveBox();
   }
 
   filterInput.addEventListener("input", renderProjects);
+  otherBtn.addEventListener("click", () => showRawCwd(cwd || homeDir));
 
   async function loadProjects(): Promise<void> {
-    recentsEl.replaceChildren(loadingRow());
+    projectsEl.replaceChildren(loadingRow());
     try {
       discovered = await fetchProjects();
     } catch {
@@ -472,12 +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);
       }
@@ -494,34 +606,66 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
     emit();
   }
 
-  function projectRow(project: Project): HTMLElement {
-    const row = document.createElement("button");
-    row.type = "button";
-    row.className = `project-row${project.is_worktree ? " is-worktree" : ""}${
-      isStale(project, new Date()) ? " is-stale" : ""
-    }`;
-    row.dataset.cwd = project.path;
-    // Abbreviate exactly like the sidebar: home → `~`, then collapse leading
-    // segments to initials (`~/g/n/maestro`). The full path stays in the tooltip
-    // and `dataset.cwd` (what's actually submitted).
-    const display = abbreviateFolderName(abbreviateCwd(project.path, homeDir));
-    row.innerHTML = `
-      <span class="project-info">
-        <span class="project-name">${escapeHtml(project.name)}</span>
-        <span class="recent-dir" title="${escapeHtml(project.path)}">${display}</span>
-      </span>
-      <span class="recent-cmd">${escapeHtml(project.last_command ?? "")}</span>`;
-    row.addEventListener("click", () => selectProject(project));
-    return row;
+  /** Put the two steps back on a restored draft's cwd, without re-running the
+   * side effects of a fresh pick. */
+  function restoreSelection(path: string): boolean {
+    for (const group of groups) {
+      const wt = worktreesOf(group).find((p) => p.path === path);
+      const choice: WorktreeChoice | null =
+        wt ? wt.path : group.main.path === path ? "new" : null;
+      if (choice === null) continue;
+      selectedGroup = group;
+      worktreeChoice = choice;
+      renderWorktreeChoices(group);
+      markActiveChoice();
+      markActiveBox();
+      return true;
+    }
+    return false;
   }
 
-  function otherDirRow(): HTMLElement {
-    const row = document.createElement("button");
-    row.type = "button";
-    row.className = "project-row project-other";
-    row.innerHTML = `<span class="project-info"><span class="recent-dir">Other directory…</span></span>`;
-    row.addEventListener("click", () => showRawCwd(cwd || homeDir));
-    return row;
+  function projectBox(group: ProjectGroup): HTMLElement {
+    const project = group.main;
+    const box = document.createElement("button");
+    box.type = "button";
+    box.className = `project-box${isStale(project, new Date()) ? " is-stale" : ""}`;
+    box.dataset.cwd = project.path;
+    const trees = worktreesOf(group).length;
+    // The full path, not the sidebar's `~/t/n/maestro` abbreviation: it is what
+    // tells two projects sharing a basename apart (#95).
+    const meta = [trees > 0 ? `${trees} worktree${trees === 1 ? "" : "s"}` : "", project.last_command ?? ""]
+      .filter(Boolean)
+      .join(" · ");
+    box.innerHTML = `
+      <span class="project-name">${escapeHtml(project.name)}</span>
+      <span class="project-path">${escapeHtml(project.path)}</span>
+      <span class="project-meta">${escapeHtml(meta)}</span>`;
+    box.addEventListener("click", () => selectProject(group));
+    return box;
+  }
+
+  function renderWorktreeChoices(group: ProjectGroup): void {
+    wtChoices.replaceChildren();
+    wtChoices.appendChild(
+      choiceButton("new", "+ new", `new worktree of ${group.main.name}`),
+    );
+    for (const wt of worktreesOf(group)) {
+      wtChoices.appendChild(choiceButton(wt.path, wt.name, wt.path));
+    }
+    wtStep.hidden = false;
+  }
+
+  function choiceButton(choice: WorktreeChoice, label: string, sub: string): HTMLElement {
+    const btn = document.createElement("button");
+    btn.type = "button";
+    btn.className = `wt-choice${choice === "new" ? " wt-choice-new" : ""}`;
+    btn.dataset.kind = choice === "new" ? "new" : "existing";
+    if (choice !== "new") btn.dataset.cwd = choice;
+    btn.innerHTML = `
+      <span class="wt-choice-name">${escapeHtml(label)}</span>
+      <span class="wt-choice-sub">${escapeHtml(sub)}</span>`;
+    btn.addEventListener("click", () => applyWorktreeChoice(choice));
+    return btn;
   }
 
   function loadingRow(): HTMLElement {
@@ -531,6 +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
@@ -569,7 +725,20 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
       applyProjectRepo(project.base_repo ?? project.path);
       return;
     }
-    void probeGitRoot();
+    scheduleGitRootProbe();
+  }
+
+  // Every keystroke resets this timer, so a burst of typing issues one
+  // request once the operator pauses. `probeToken` inside probeGitRoot still
+  // owns ordering: a scheduled probe that fires after a newer one started
+  // loses the token race and is dropped.
+  let probeTimer: number | undefined;
+  function scheduleGitRootProbe(): void {
+    window.clearTimeout(probeTimer);
+    probeTimer = window.setTimeout(() => {
+      probeTimer = undefined;
+      void probeGitRoot();
+    }, GITROOT_PROBE_DEBOUNCE_MS);
   }
 
   async function probeGitRoot(): Promise<void> {
@@ -598,6 +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;
@@ -671,6 +841,7 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
   branchSelect.addEventListener("change", () => emit());
 
   wtEnabled.addEventListener("change", () => {
+    updateWtSummary();
     emit();
     if (wtEnabled.checked) {
       resolveBaseRepo();
@@ -684,6 +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);
 
@@ -694,6 +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();
@@ -730,6 +939,7 @@ export function createSpawnForm(opts: SpawnFormOptions): SpawnFormHandle {
     el: form,
     destroy() {
       destroyed = true;
+      window.clearTimeout(probeTimer);
       autocomplete.destroy();
       form.remove();
     },

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

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

web/src/spawnFormWorktree.test.ts

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

web/src/styles.css

@@ -727,10 +727,8 @@ textarea {
 }
 
 /* Earlier path segments collapse to their initial; the trailing segment (the
-   one that actually names the dir) stays full. Dim the collapsed prefix. Shared
-   by the sidebar tree and the spawn dialog's recent-directory picker. */
-.folder-name .folder-stem,
-.recent-dir .folder-stem {
+   one that actually names the dir) stays full. Dim the collapsed prefix. */
+.folder-name .folder-stem {
   color: var(--faint);
 }
 
@@ -789,60 +787,85 @@ textarea {
   font-weight: 400;
 }
 
+/* #107: session cards per docs/SIDEBAR.md — line 1 (name + top-right actions)
+   always, line 2 (meta) only when it has something to say. */
+.tree-leaf.session-card {
+  flex-direction: column;
+  align-items: stretch;
+  gap: 1px;
+}
+
+.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;
-  overflow: hidden;
-  text-overflow: ellipsis;
-  white-space: nowrap;
-}
-
-.leaf-meta {
-  font-size: var(--fs-11);
-  color: var(--muted);
-  margin-left: auto;
-  padding-left: var(--sp-2);
+  /* Grows to push the actions to the right edge but shrinks first, so the name
+     truncates before it can ever reach them — overlap is a defect (#107). */
+  flex: 1 1 auto;
   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;
-  text-transform: uppercase;
+  min-width: 0;
   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
-   refused, and the operator should see that before pressing the button. */
-.leaf-badge.leaf-blocked {
-  color: var(--warn, #b45309);
-  border-color: var(--warn, #b45309);
+.activity-duration {
+  color: inherit;
+  flex: 0 0 auto;
 }
 
+/* Blocked-work / exited / command fragments recede: the ⚠ glyph already
+   signals severity and "exited" dims with the row. */
+.card-flag {
+  color: var(--faint);
+  min-width: 0;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+/* 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;
-  right: var(--sp-1);
-  top: 50%;
-  transform: translateY(-50%);
+  flex: 0 0 auto;
+  margin-left: auto;
   display: inline-flex;
   gap: 2px;
 }
@@ -1286,18 +1309,33 @@ textarea {
 .worktree {
   border: 1px solid var(--border);
   border-radius: var(--r-2);
-  padding: var(--sp-3);
+  padding: 0 var(--sp-3);
   margin: 0;
   display: flex;
   flex-direction: column;
-  gap: var(--sp-3);
   background: color-mix(in oklab, var(--surface-2) 50%, transparent);
 }
 
-.worktree legend {
-  padding: 0 6px;
-  color: var(--ink);
-  font-size: var(--fs-13);
+.worktree .wt-toggle {
+  margin: 0 calc(var(--sp-3) * -1);
+  padding-left: var(--sp-3);
+  width: calc(100% + var(--sp-3) * 2);
+}
+
+.wt-summary {
+  color: var(--muted);
+  font-size: var(--fs-12);
+}
+
+.wt-collapsible {
+  display: flex;
+  flex-direction: column;
+  gap: var(--sp-3);
+  padding-bottom: var(--sp-3);
+}
+
+.wt-collapsible[hidden] {
+  display: none;
 }
 
 .form-error {
@@ -1381,8 +1419,9 @@ textarea {
   color: var(--muted);
 }
 
-/* Project picker rows (#59). Worktree rows are indented under their base
-   repository; rows stale beyond 7 days are dimmed but still selectable. */
+/* Working-directory picker (#95). Two steps: a grid of project boxes, then the
+   picked project's worktree choices. Stale beyond 7 days dims but stays
+   selectable. */
 .picker {
   display: flex;
   flex-direction: column;
@@ -1397,73 +1436,155 @@ textarea {
   width: 100%;
 }
 
-.project-row {
+/* `display` from `.field`/`.raw-wrap` outranks the UA sheet's `[hidden]`, so
+   step two and the raw-cwd hatch stayed visible while hidden. */
+.wt-step[hidden],
+.raw-wrap[hidden] {
+  display: none;
+}
+
+.picker.projects {
+  display: grid;
+  grid-template-columns: repeat(auto-fill, minmax(190px, 1fr));
+  align-content: start;
+  gap: var(--sp-2);
+  max-height: 300px;
+  padding: 1px;
+}
+
+.project-box {
+  display: flex;
+  flex-direction: column;
+  gap: 2px;
+  min-width: 0;
+  padding: var(--sp-2) var(--sp-3);
+  background: var(--surface-2);
+  border: 1px solid var(--border);
+  border-radius: var(--r-2);
+  color: var(--ink);
+  font-family: inherit;
+  text-align: left;
+  cursor: pointer;
+  transition:
+    border-color var(--dur-fast) var(--ease-out),
+    background var(--dur-fast) var(--ease-out);
+}
+
+.project-box:hover {
+  border-color: var(--border-strong);
+}
+
+.project-box.is-active {
+  border-color: var(--accent);
+  background: var(--accent-tint);
+}
+
+.project-box.is-stale {
+  opacity: 0.55;
+}
+
+.project-name {
+  font-size: var(--fs-13);
+  font-weight: 600;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+/* The whole path, never abbreviated — it is what tells two projects sharing a
+   basename apart. Wraps rather than truncating so none of it is hidden. */
+.project-path {
+  font-family: var(--font-mono);
+  font-size: var(--fs-12);
+  line-height: 1.35;
+  color: var(--muted);
+  overflow-wrap: anywhere;
+}
+
+.project-meta {
+  font-family: var(--font-mono);
+  font-size: var(--fs-12);
+  color: var(--faint);
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.project-meta:empty {
+  display: none;
+}
+
+.project-other {
+  align-self: flex-start;
+  padding: 4px 0;
+  min-height: 30px;
+  background: none;
+  border: 0;
+  color: var(--muted);
+  font-family: inherit;
+  font-size: var(--fs-13);
+  font-style: italic;
+  text-align: left;
+  cursor: pointer;
+}
+
+.project-other:hover {
+  color: var(--ink);
+}
+
+/* Step two: "+ new" (create one) or an existing worktree (run in it). */
+.picker.wt-choices {
+  max-height: 200px;
+}
+
+.wt-choice {
   display: flex;
   align-items: baseline;
   justify-content: space-between;
   gap: var(--sp-3);
+  min-height: 32px;
   padding: 6px var(--sp-3);
   background: var(--surface-2);
   border: 1px solid var(--border);
   border-radius: var(--r-2);
   color: var(--ink);
   font-family: inherit;
-  cursor: pointer;
   text-align: left;
+  cursor: pointer;
   transition:
     border-color var(--dur-fast) var(--ease-out),
     background var(--dur-fast) var(--ease-out);
 }
 
-.project-row:hover {
+.wt-choice:hover {
   border-color: var(--border-strong);
 }
 
-.project-row.is-active {
+.wt-choice.is-active {
   border-color: var(--accent);
   background: var(--accent-tint);
 }
 
-.project-row.is-worktree {
-  margin-left: var(--sp-4);
-}
-
-.project-row.is-stale {
-  opacity: 0.55;
-}
-
-.project-info {
-  display: flex;
-  align-items: baseline;
-  gap: var(--sp-2);
-  min-width: 0;
-}
-
-.project-name {
+.wt-choice-name {
+  flex: 0 0 auto;
   font-size: var(--fs-13);
   font-weight: 600;
   white-space: nowrap;
 }
 
-.recent-dir {
+.wt-choice-new .wt-choice-name {
   font-family: var(--font-mono);
-  font-size: var(--fs-12);
-  color: var(--muted);
-  overflow: hidden;
-  text-overflow: ellipsis;
-  white-space: nowrap;
+  color: var(--accent);
 }
 
-.recent-cmd {
-  flex: 0 0 auto;
+.wt-choice-sub {
+  min-width: 0;
   font-family: var(--font-mono);
   font-size: var(--fs-12);
+  line-height: 1.35;
   color: var(--muted);
-}
-
-.project-other .recent-dir {
-  font-family: inherit;
-  font-style: italic;
+  text-align: right;
+  overflow-wrap: anywhere;
 }
 
 .picker-empty {

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. */
-export type ActivityState = "Active" | "Idle" | "AwaitingInput";
+ * Absent on payloads from daemons that predate the field. `Error` is only set
+ * when an agent reports failure (#105); the daemon never infers it. */
+export type ActivityState = "Active" | "Idle" | "AwaitingInput" | "Error";
 
 export interface Session {
   id: Uuid;
@@ -27,6 +28,11 @@ export interface Session {
   activity?: ActivityState;
   /** 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 +42,16 @@ 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 +247,23 @@ 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);
+  });
+});