feat(maestro): open the bar with ctrl-k over a focused pane

The global listener already ran in the capture phase, but deferred to
isTypingTarget, so xterm's hidden textarea kept Ctrl-K. The bar now treats
that textarea as not a typing target, while real form fields — the spawn
form's inputs — keep their own Ctrl-K.

Leader then ctrl-k (ctrl-a ctrl-k) sends the literal 0x0B to the focused
pane through the leader chord the command set already resolves, so
readline's kill-to-end-of-line stays reachable. The pool grows a
sendToFocused for it, over a new AttachConnection.sendInput.

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

CLAUDE.md

@@ -87,6 +87,11 @@ or is upgraded under them — the build stamp on `/api/info`, the status
 indicator's states, the blocking overlay, grace and poll timings. Read it
 before changing reconnect behaviour on either client.
 
+`docs/COMMAND-BAR.md` is the contract for the `ctrl-k` command bar in both
+clients — how it opens, the sigils, the key model, the match-and-rank algorithm
+the two matchers must agree on, and the fixture table they are tested against.
+Read it before changing either bar or either matcher.
+
 `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

@@ -251,6 +251,7 @@ mod tests {
             activity_since: chrono::Utc::now(),
             current_cwd: None,
             blocked_work: None,
+            last_focused_at: None,
         }
     }
 

crates/maestro-daemon/src/session.rs

@@ -285,33 +285,50 @@ impl SessionManager {
     /// Subscribe to a session's PTY broadcast and return the replay buffer
     /// (NAP-229). Callers send the buffer before pumping the live receiver
     /// so freshly-attached clients see the last screenful immediately.
+    ///
+    /// Opening an attach is focusing (#145): it stamps
+    /// [`Session::last_focused_at`], the same field `set_focused` stamps, so
+    /// a client that only ever attaches sorts identically to one that
+    /// reports focus explicitly.
     pub async fn subscribe_pty_with_replay(
         &self,
         id: Uuid,
     ) -> Option<(Vec<u8>, broadcast::Receiver<Vec<u8>>)> {
         let tmux = self.inner.tmux.clone();
-        let sessions = self.inner.sessions.lock().await;
-        let rec = sessions.get(&id)?;
-        // For a live session, tmux's own screen beats the byte tail: the tail
-        // starts mid-stream, so a full-screen program (an agent TUI) replayed
-        // from it renders as garbage until something forces a repaint. A dead
-        // session has no pane left to capture, so it keeps the byte tail.
-        let alive = rec.session.status == SessionStatus::Running;
-        // The capture shells out to tmux while the replay lock is held, which
-        // parks the reader for the length of one tmux round-trip. That only
-        // happens on attach, and the alternative is a seam in the stream.
-        Some(rec.bridge.subscribe_with_snapshot(|| {
-            if !alive {
-                return None;
-            }
-            match tmux.capture_pane(id) {
-                Ok(snapshot) => snapshot,
-                Err(e) => {
-                    tracing::warn!(error = ?e, %id, "capture-pane failed; replaying raw bytes");
-                    None
+        let (result, updated) = {
+            let mut sessions = self.inner.sessions.lock().await;
+            let rec = sessions.get_mut(&id)?;
+            rec.session.last_focused_at = Some(Utc::now());
+            let updated = rec.session.clone();
+            // For a live session, tmux's own screen beats the byte tail: the
+            // tail starts mid-stream, so a full-screen program (an agent TUI)
+            // replayed from it renders as garbage until something forces a
+            // repaint. A dead session has no pane left to capture, so it
+            // keeps the byte tail.
+            let alive = rec.session.status == SessionStatus::Running;
+            // The capture shells out to tmux while the replay lock is held,
+            // which parks the reader for the length of one tmux round-trip.
+            // That only happens on attach, and the alternative is a seam in
+            // the stream.
+            let result = rec.bridge.subscribe_with_snapshot(|| {
+                if !alive {
+                    return None;
                 }
-            }
-        }))
+                match tmux.capture_pane(id) {
+                    Ok(snapshot) => snapshot,
+                    Err(e) => {
+                        tracing::warn!(error = ?e, %id, "capture-pane failed; replaying raw bytes");
+                        None
+                    }
+                }
+            });
+            (result, updated)
+        };
+        let _ = self
+            .inner
+            .events
+            .send(CatalogEvent::SessionUpdated { session: updated });
+        Some(result)
     }
 
     pub async fn has(&self, id: Uuid) -> bool {
@@ -448,6 +465,7 @@ impl SessionManager {
             // The watcher fills this in on its first blocked-work pass; a
             // fresh tree has nothing in the way anyway.
             blocked_work: None,
+            last_focused_at: None,
         };
 
         if let Err(e) = self.inner.sidecar.write(&session) {
@@ -652,6 +670,7 @@ impl SessionManager {
 
                     current_cwd: None,
                     blocked_work: None,
+                    last_focused_at: None,
                 },
             };
             let fifo_path = self.inner.fifo_dir.join(format!("{id}.fifo"));
@@ -838,11 +857,26 @@ impl SessionManager {
     /// Record whether a client's pane is currently showing `id`. Read by the
     /// activity pass's next tick to decide whether an `AwaitingInput` glow
     /// has been looked at long enough to clear (`apply_focus_suppression`).
-    /// An unknown session is [`SessionError::NotFound`].
+    /// Gaining focus also stamps [`Session::last_focused_at`] (#145) — losing
+    /// it does not, since the command bar's ordering cares about the last
+    /// time the operator arrived, not when they left. An unknown session is
+    /// [`SessionError::NotFound`].
     pub async fn set_focused(&self, id: Uuid, focused: bool) -> Result<(), SessionError> {
-        let mut sessions = self.inner.sessions.lock().await;
-        let rec = sessions.get_mut(&id).ok_or(SessionError::NotFound(id))?;
-        rec.focused_since = focused.then(std::time::Instant::now);
+        let updated = {
+            let mut sessions = self.inner.sessions.lock().await;
+            let rec = sessions.get_mut(&id).ok_or(SessionError::NotFound(id))?;
+            rec.focused_since = focused.then(std::time::Instant::now);
+            if focused {
+                rec.session.last_focused_at = Some(Utc::now());
+            }
+            focused.then(|| rec.session.clone())
+        };
+        if let Some(session) = updated {
+            let _ = self
+                .inner
+                .events
+                .send(CatalogEvent::SessionUpdated { session });
+        }
         Ok(())
     }
 }

crates/maestro-daemon/tests/local_api.rs

@@ -383,6 +383,41 @@ async fn patch_unknown_session_returns_404() {
     assert_eq!(resp.status(), reqwest::StatusCode::NOT_FOUND);
 }
 
+/// #145: `POST /.../focus` with `focused: true` over HTTP stamps
+/// `last_focused_at`, observable on the next `GET /api/sessions`.
+#[tokio::test]
+async fn post_focus_stamps_last_focused_at() {
+    let h = spawn("naps-laptop").await;
+    let session = h
+        .manager
+        .create(CreateSessionRequest {
+            cwd: "/tmp".into(),
+            command: "sleep 60".into(),
+            env: HashMap::new(),
+            metadata: HashMap::new(),
+            worktree: None,
+        })
+        .await
+        .unwrap();
+    assert_eq!(session.last_focused_at, None);
+
+    let resp = reqwest::Client::new()
+        .post(url(h.addr, &format!("/api/sessions/{}/focus", session.id)))
+        .json(&serde_json::json!({ "focused": true }))
+        .send()
+        .await
+        .unwrap();
+    assert_eq!(resp.status(), reqwest::StatusCode::NO_CONTENT);
+
+    let sessions: Vec<Session> = reqwest::get(url(h.addr, "/api/sessions"))
+        .await
+        .unwrap()
+        .json()
+        .await
+        .unwrap();
+    assert!(sessions[0].last_focused_at.is_some());
+}
+
 #[tokio::test]
 async fn delete_owned_session_kills_it() {
     let h = spawn("naps-laptop").await;

crates/maestro-daemon/tests/session_manager.rs

@@ -1091,3 +1091,109 @@ async fn spawned_sessions_export_maestro_session_id_and_url() {
 
     fx.manager.kill(s.id, false).await.expect("kill");
 }
+
+/// docs/COMMAND-BAR.md, empty-query ordering: a session that has never been
+/// focused carries no `last_focused_at` at all, which is what lets a client
+/// sort it after every session that has one (#145).
+#[tokio::test]
+async fn a_freshly_created_session_has_never_been_focused() {
+    let fx = DaemonFixture::new();
+    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");
+
+    assert_eq!(s.last_focused_at, None);
+    assert_eq!(fx.manager.snapshot().await[0].last_focused_at, None);
+}
+
+/// #145: `POST /.../focus` reporting `focused: true` stamps
+/// `last_focused_at` and announces it on the event stream; reporting
+/// `focused: false` (losing focus) leaves the stamp alone, since the bar
+/// orders by when the operator last arrived, not when they left.
+#[tokio::test]
+async fn set_focused_true_stamps_last_focused_at() {
+    let fx = DaemonFixture::new();
+    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 mut events = fx.manager.events();
+    let before = chrono::Utc::now();
+    fx.manager.set_focused(s.id, true).await.expect("focus");
+
+    let updated = fx.manager.snapshot().await[0].clone();
+    let stamp = updated.last_focused_at.expect("stamped on focus");
+    assert!(stamp >= before);
+
+    let mut saw_update = false;
+    while let Ok(event) = tokio::time::timeout(Duration::from_millis(200), events.recv()).await {
+        if let Ok(CatalogEvent::SessionUpdated { session }) = event {
+            if session.id == s.id && session.last_focused_at == Some(stamp) {
+                saw_update = true;
+                break;
+            }
+        }
+    }
+    assert!(saw_update, "expected a SessionUpdated carrying the stamp");
+
+    fx.manager.set_focused(s.id, false).await.expect("unfocus");
+    let after_unfocus = fx.manager.snapshot().await[0].clone();
+    assert_eq!(
+        after_unfocus.last_focused_at,
+        Some(stamp),
+        "losing focus must not clear the last-focused stamp"
+    );
+}
+
+/// #145: opening `/api/attach/:id` is focusing too — it must stamp the same
+/// field `set_focused` does, so a client that only ever attaches sorts
+/// identically to one that reports focus explicitly.
+#[tokio::test]
+async fn attaching_stamps_last_focused_at() {
+    let fx = DaemonFixture::new();
+    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");
+    assert_eq!(s.last_focused_at, None);
+
+    let before = chrono::Utc::now();
+    let (_replay, _rx) = fx
+        .manager
+        .subscribe_pty_with_replay(s.id)
+        .await
+        .expect("known session");
+
+    let updated = fx.manager.snapshot().await[0].clone();
+    let stamp = updated.last_focused_at.expect("attach stamps focus");
+    assert!(stamp >= before);
+}

crates/maestro-daemon/tests/sidecar.rs

@@ -31,6 +31,7 @@ fn sample(id: Uuid) -> Session {
         activity_since: chrono::Utc::now(),
         current_cwd: Some(PathBuf::from("/tmp/work/crates")),
         blocked_work: None,
+        last_focused_at: None,
     }
 }
 

crates/maestro-protocol/src/display.rs

@@ -202,6 +202,41 @@ pub fn command_program(command: &str) -> String {
     }
 }
 
+/// Program name (already basenamed and lowercased) -> the tool id its mark
+/// stands for. Mirrors the web's `BY_PROGRAM` in `web/src/toolIcon.ts`;
+/// recognition is deliberately narrow, so an unrecognised program has no tool.
+const BY_PROGRAM: [(&str, &str); 17] = [
+    ("claude", "claude"),
+    ("claude-code", "claude"),
+    ("codex", "codex"),
+    ("opencode", "opencode"),
+    ("gemini", "gemini"),
+    ("aider", "aider"),
+    ("cursor", "cursor"),
+    ("cursor-agent", "cursor"),
+    ("pi", "pi"),
+    ("bash", "shell"),
+    ("zsh", "shell"),
+    ("sh", "shell"),
+    ("fish", "shell"),
+    ("dash", "shell"),
+    ("ksh", "shell"),
+    ("nu", "shell"),
+    ("xonsh", "shell"),
+];
+
+/// The tool id a command line's icon stands for (`claude`, `codex`,
+/// `opencode`, ...), or `None` when the program is not one we have a mark for.
+/// The command bar matches this field (`docs/COMMAND-BAR.md`), so it must name
+/// the same tools the web's `splitCommand().tool` does.
+pub fn command_tool(command: &str) -> Option<&'static str> {
+    let program = command_program(command).to_lowercase();
+    BY_PROGRAM
+        .iter()
+        .find(|(name, _)| *name == program)
+        .map(|(_, tool)| *tool)
+}
+
 /// `FOO=bar`, the shell's own prefix for one command's environment.
 fn is_env_assignment(word: &str) -> bool {
     let mut chars = word.chars();
@@ -248,6 +283,7 @@ mod tests {
             activity_since: Utc::now(),
             current_cwd: None,
             blocked_work: None,
+            last_focused_at: None,
         }
     }
 
@@ -475,4 +511,22 @@ mod tests {
         assert_eq!(command_program("sudo"), "sudo");
         assert_eq!(command_program(""), "");
     }
+
+    /// The command bar's `tool` field (docs/COMMAND-BAR.md) names the same
+    /// tools the web's `splitCommand().tool` does.
+    #[test]
+    fn command_tool_names_the_mark_the_card_shows() {
+        assert_eq!(command_tool("claude --resume"), Some("claude"));
+        assert_eq!(command_tool("npx opencode"), Some("opencode"));
+        assert_eq!(command_tool("/bin/zsh -l"), Some("shell"));
+        assert_eq!(command_tool("CLAUDE"), Some("claude"));
+    }
+
+    /// Narrow on purpose: an unrecognised program has no mark, so the
+    /// candidate has no `tool` field to match rather than a wrong one.
+    #[test]
+    fn command_tool_is_absent_for_an_unrecognised_program() {
+        assert_eq!(command_tool("hx src/main.rs"), None);
+        assert_eq!(command_tool(""), None);
+    }
 }

crates/maestro-protocol/src/lib.rs

@@ -108,6 +108,14 @@ pub struct Session {
     /// from daemons that predate the field stay forward-compatible.
     #[serde(default)]
     pub blocked_work: Option<InTheWay>,
+    /// Wall-clock time this session last became the pane a client was
+    /// showing (#145) — stamped by both `POST /.../focus` and opening
+    /// `/api/attach/:id`, since either one is the operator moving there.
+    /// `None` until the session has been focused at least once, which is
+    /// also how the command bar's empty-query ordering (`docs/COMMAND-BAR.md`)
+    /// sorts a never-focused session after every session that has one.
+    #[serde(default)]
+    pub last_focused_at: Option<DateTime<Utc>>,
 }
 
 /// Default for [`Session::last_activity_at`] when an older payload omits it.
@@ -847,6 +855,7 @@ mod tests {
                 .with_timezone(&Utc),
             current_cwd: Some(PathBuf::from("/home/naps62/projects/maestro/crates")),
             blocked_work: None,
+            last_focused_at: None,
         }
     }
 
@@ -896,6 +905,28 @@ mod tests {
         );
     }
 
+    #[test]
+    fn last_focused_at_defaults_to_none_on_legacy_payload() {
+        // Pre-#145 payload omits the field; `None` means never-focused.
+        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.last_focused_at, None);
+
+        let mut focused = sample_session();
+        focused.last_focused_at = Some(
+            DateTime::parse_from_rfc3339("2026-05-24T12:06:00Z")
+                .unwrap()
+                .with_timezone(&Utc),
+        );
+        assert_eq!(focused, round_trip(&focused));
+    }
+
     #[test]
     fn activity_since_defaults_to_epoch_on_legacy_payload() {
         // A daemon predating #102 omits `activity_since`; it must deserialize

crates/maestro-testing/src/lib.rs

@@ -46,6 +46,7 @@ pub fn session(id: Uuid, cwd: &str, command: &str) -> Session {
         activity_since: chrono::Utc::now(),
         current_cwd: None,
         blocked_work: None,
+        last_focused_at: None,
     }
 }
 

crates/maestro-tui/src/action.rs

@@ -53,6 +53,9 @@ pub enum Action {
     RenameHighlighted,
 
     // Chrome
+    /// Open the `ctrl-k` command bar (`docs/COMMAND-BAR.md`) — a query line
+    /// over the sessions, ranked by the shared matcher.
+    OpenCommandBar,
     ToggleSidebar,
     ShowHelp,
     Quit,
@@ -94,6 +97,7 @@ impl Action {
             Action::FastForwardSpawn => "Create session with defaults".into(),
             Action::KillHighlighted => "Kill selected session".into(),
             Action::RenameHighlighted => "Rename selected session".into(),
+            Action::OpenCommandBar => "Go to a session".into(),
             Action::ToggleSidebar => "Show or hide sidebar".into(),
             Action::ShowHelp => "Show help".into(),
             Action::Quit => "Quit Maestro".into(),
@@ -120,6 +124,7 @@ impl Action {
             "FastForwardSpawn" => return Ok(Action::FastForwardSpawn),
             "KillHighlighted" => return Ok(Action::KillHighlighted),
             "RenameHighlighted" => return Ok(Action::RenameHighlighted),
+            "OpenCommandBar" => return Ok(Action::OpenCommandBar),
             "ToggleSidebar" => return Ok(Action::ToggleSidebar),
             "ShowHelp" => return Ok(Action::ShowHelp),
             "Quit" => return Ok(Action::Quit),
@@ -239,10 +244,23 @@ mod tests {
         );
     }
 
+    /// The command bar is an ordinary keymap entry, so it must round-trip
+    /// like every other action (#153).
+    #[test]
+    fn open_command_bar_round_trips() {
+        assert_eq!(
+            Action::parse("OpenCommandBar").unwrap(),
+            Action::OpenCommandBar
+        );
+        assert_eq!(Action::OpenCommandBar.to_string(), "OpenCommandBar");
+        assert_eq!(Action::OpenCommandBar.help_label(), "Go to a session");
+    }
+
     #[test]
     fn display_round_trips() {
         for a in [
             Action::EnterInsert,
+            Action::OpenCommandBar,
             Action::RenameHighlighted,
             Action::Quit,
             Action::OpenSpawnModal,

crates/maestro-tui/src/app.rs

@@ -23,6 +23,7 @@ use uuid::Uuid;
 
 use crate::action::Action;
 use crate::catalog::CatalogStore;
+use crate::command_bar::{BarOutcome, BarTarget, CommandBar};
 use crate::config::TuiConfig;
 use crate::daemon_link::DaemonLink;
 use crate::draft::{DraftInputResult, DraftPane};
@@ -78,6 +79,9 @@ pub struct App {
     /// Edit buffer behind [`OverlayKind::Rename`] (#125), kept here for the
     /// same reason the worktree entries are.
     rename_input: TextInput,
+    /// Query buffer and result list behind [`OverlayKind::CommandBar`] (#153),
+    /// kept here for the same reason the rename buffer is.
+    command_bar: Option<CommandBar>,
     region: RegionMap,
     last_sent_size: HashMap<Uuid, (u16, u16)>,
     clicks: ClickTracker,
@@ -87,10 +91,13 @@ pub struct App {
     /// that can move `Focus::Pane` (attach, tab switch, sidebar toggle,
     /// mouse) is covered without each one remembering to report it.
     focused_session: Option<Uuid>,
-    /// A sidebar highlight waiting out its debounce before it becomes a
-    /// preview (`docs/PREVIEW.md`). Walking the list with `j` held down must
-    /// not open an attach per row it passes over.
+    /// A sidebar highlight waiting for the pane's minimum gap before it
+    /// becomes a preview (`docs/PREVIEW.md`). Walking the list with `j` held
+    /// down must not open an attach per row it passes over.
     pending_preview: Option<(Uuid, std::time::Instant)>,
+    /// When the pane last swapped what it previews. `None` until the first
+    /// one, which is why a highlight landing on a still sidebar shows at once.
+    last_preview_at: Option<std::time::Instant>,
     /// Sessions attached only because they were previewed, oldest first. Kept
     /// connected past the preview so stepping back onto a row is instant, and
     /// bounded so a long walk doesn't leave a socket per session behind.
@@ -125,10 +132,11 @@ struct FrameKey {
 /// else changed.
 const CLOCK_REFRESH: Duration = Duration::from_secs(1);
 
-/// How long a highlight has to stand still before the pane previews it
-/// (`docs/PREVIEW.md`). Long enough that a fast walk down the list doesn't
-/// attach to every row it crosses, short enough to read as immediate.
-const PREVIEW_DELAY: Duration = Duration::from_millis(120);
+/// Shortest gap between two pane swaps (`docs/PREVIEW.md`). The first
+/// highlight to land shows at once; this only bounds how often the pane may
+/// follow after that, so a fast walk down the list attaches to the row it
+/// started on and the row it stopped on rather than every row between.
+const PREVIEW_GAP: Duration = Duration::from_millis(120);
 
 /// How many preview-only attaches to keep connected behind the current one.
 const PREVIEW_BUDGET: usize = 3;
@@ -206,6 +214,7 @@ impl App {
             link,
             http,
             rename_input: TextInput::default(),
+            command_bar: None,
             draft_tx,
             draft_rx,
             region: RegionMap::default(),
@@ -213,6 +222,7 @@ impl App {
             clicks: ClickTracker::default(),
             focused_session: None,
             pending_preview: None,
+            last_preview_at: None,
             preview_lru: Vec::new(),
             last_frame: None,
             last_drawn_at: std::time::Instant::now(),
@@ -425,6 +435,32 @@ impl App {
                     (OverlayDecision::Consumed, Vec::new())
                 }
             },
+            // The bar owns every key while it is up: the keymap must not see
+            // `j`, `x` or `q` as commands mid-query.
+            Some(OverlayKind::CommandBar) => {
+                let outcome = match self.command_bar.as_mut() {
+                    Some(bar) => bar.handle_key(key),
+                    None => BarOutcome::Close,
+                };
+                match outcome {
+                    BarOutcome::Stay => (OverlayDecision::Consumed, Vec::new()),
+                    BarOutcome::Close => {
+                        self.close_command_bar();
+                        (OverlayDecision::Consumed, Vec::new())
+                    }
+                    BarOutcome::Open(BarTarget::Session(sid)) => {
+                        self.close_command_bar();
+                        // The same open path the sidebar's own attach uses, so
+                        // a bar attach can never leave the layout in a state a
+                        // highlight-and-enter could not produce.
+                        self.state.sidebar_highlight = Some(SidebarItem::Session(sid));
+                        (
+                            OverlayDecision::Consumed,
+                            self.dispatch(Action::AttachHighlighted),
+                        )
+                    }
+                }
+            }
             Some(OverlayKind::Help) => {
                 self.state.dismiss_overlay();
                 (OverlayDecision::Consumed, Vec::new())
@@ -470,6 +506,7 @@ impl App {
                 };
                 self.state.show_overlay(OverlayKind::Help);
             }
+            Action::OpenCommandBar => self.open_command_bar(),
             Action::OpenSpawnModal => {
                 self.open_spawn_modal();
                 effects.push(Effect::LoadDraft);
@@ -526,18 +563,28 @@ impl App {
     }
 
     /// Recompute what the pane should be previewing. A session highlighted in
-    /// the sidebar is previewed after [`PREVIEW_DELAY`]; anything else — a
-    /// group row, the pane holding the keyboard, or the highlight already
-    /// sitting on the attached session — clears the preview at once.
+    /// the sidebar is previewed as soon as [`PREVIEW_GAP`] has passed since the
+    /// last swap — immediately, for a highlight landing on a still list.
+    /// Anything else — a group row, the pane holding the keyboard, or the
+    /// highlight already sitting on the attached session — clears at once.
     fn refresh_preview(&mut self) {
         let wanted = match (self.state.focus, &self.state.sidebar_highlight) {
+            // The bar is a view over the app, not a place in it: while it is
+            // up the sidebar highlight behind it previews nothing
+            // (`docs/COMMAND-BAR.md`, "Focus round-trip").
+            _ if self.state.overlay() == Some(&OverlayKind::CommandBar) => None,
             (Focus::Sidebar, Some(SidebarItem::Session(sid))) => Some(*sid),
             _ => None,
         };
         match wanted {
             Some(sid) if self.state.active_session() != Some(sid) => {
                 if self.state.preview != Some(sid) {
-                    self.pending_preview = Some((sid, std::time::Instant::now() + PREVIEW_DELAY));
+                    let now = std::time::Instant::now();
+                    let due = match self.last_preview_at {
+                        Some(last) if now < last + PREVIEW_GAP => last + PREVIEW_GAP,
+                        _ => now,
+                    };
+                    self.pending_preview = Some((sid, due));
                 }
             }
             _ => {
@@ -547,8 +594,8 @@ impl App {
         }
     }
 
-    /// The debounce elapsed: show the highlighted session, attaching it if
-    /// nothing already is.
+    /// The pane is free to follow: show the highlighted session, attaching it
+    /// if nothing already is.
     fn poll_due_preview_at(&mut self, now: std::time::Instant) -> Vec<Effect> {
         let Some((sid, due)) = self.pending_preview else {
             return Vec::new();
@@ -560,6 +607,7 @@ impl App {
         if self.state.preview == Some(sid) {
             return Vec::new();
         }
+        self.last_preview_at = Some(now);
         self.state.preview = Some(sid);
         // Set outside the input path, so nothing else marks the frame stale.
         self.epoch = self.epoch.wrapping_add(1);
@@ -576,6 +624,25 @@ impl App {
         }
     }
 
+    /// Put the command bar up over whatever is behind it (#153). Opening
+    /// while a session is previewed discards the preview first, like any
+    /// other real change (`docs/PREVIEW.md`); focus and mode are left alone,
+    /// so closing gives the keyboard back to whatever held it.
+    fn open_command_bar(&mut self) {
+        let snapshot = self.catalog.snapshot();
+        self.command_bar = Some(CommandBar::new(&snapshot.sessions, &self.home_dir));
+        self.pending_preview = None;
+        self.clear_preview();
+        self.state.show_overlay(OverlayKind::CommandBar);
+    }
+
+    /// Take the bar down, dropping its query. Every exit goes through here so
+    /// a stale buffer can never outlive the overlay.
+    fn close_command_bar(&mut self) {
+        self.command_bar = None;
+        self.state.dismiss_overlay();
+    }
+
     fn clear_preview(&mut self) {
         if self.state.preview.take().is_some() {
             self.epoch = self.epoch.wrapping_add(1);
@@ -1167,6 +1234,10 @@ impl App {
             sessions: snap.sessions.clone(),
             highlight: self.state.sidebar_highlight.clone(),
             attached,
+            // The active tab's session, not the displayed one: a preview is
+            // shown in the pane but never becomes what the operator picked,
+            // so it must not move this fill (`docs/PREVIEW.md`).
+            pane_session: self.state.active_session(),
         };
         let shown_sid = self.state.displayed_session();
         let previewing = self.state.preview.is_some();
@@ -1206,6 +1277,7 @@ impl App {
             draft: self.draft.as_ref(),
             help: &self.help,
             rename_input: &self.rename_input,
+            command_bar: self.command_bar.as_ref(),
             link: &link_status,
         };
 
@@ -1257,6 +1329,7 @@ fn visible_sidebar_order(
         sessions: snap.sessions.clone(),
         highlight: None,
         attached: HashSet::new(),
+        pane_session: None,
     }
     .rendered_items_with_collapsed(collapsed)
 }
@@ -1653,6 +1726,7 @@ mod tests {
                     activity_since: chrono::Utc::now(),
                     current_cwd: None,
                     blocked_work: None,
+                    last_focused_at: None,
                 })
                 .collect(),
         });
@@ -1671,24 +1745,22 @@ mod tests {
         }
     }
 
-    fn after_debounce() -> std::time::Instant {
-        std::time::Instant::now() + PREVIEW_DELAY + Duration::from_millis(1)
+    fn after_gap() -> std::time::Instant {
+        std::time::Instant::now() + PREVIEW_GAP + Duration::from_millis(1)
     }
 
     /// docs/PREVIEW.md: the highlight shows a session in the pane without the
     /// tab taking it on.
     #[test]
-    fn highlighting_a_session_previews_it_once_the_debounce_elapses() {
+    fn highlighting_a_session_previews_it_without_waiting() {
         let a = Uuid::from_u128(1);
         let mut app = app_with_sessions(&[a]);
         app.dispatch(Action::SidebarNext);
 
-        // Nothing yet: the highlight has to stand still first.
-        assert_eq!(app.poll_due_preview_at(std::time::Instant::now()), vec![]);
-        assert_eq!(app.state.preview, None);
-
+        // The list was still, so the pane follows on the next poll — no gap to
+        // wait out first (docs/PREVIEW.md).
         assert_eq!(
-            app.poll_due_preview_at(after_debounce()),
+            app.poll_due_preview_at(std::time::Instant::now()),
             vec![Effect::Attach(a)]
         );
         assert_eq!(app.state.preview, Some(a));
@@ -1697,6 +1769,28 @@ mod tests {
         assert_eq!(app.state.active_tab().session(), None);
     }
 
+    /// The gap only bounds the *second* swap, so a burst costs two mounts.
+    #[test]
+    fn a_second_move_inside_the_gap_waits_for_it() {
+        let a = Uuid::from_u128(1);
+        let b = Uuid::from_u128(2);
+        let mut app = app_with_sessions(&[a, b]);
+
+        app.dispatch(Action::SidebarNext);
+        let now = std::time::Instant::now();
+        assert_eq!(app.poll_due_preview_at(now), vec![Effect::Attach(a)]);
+
+        app.dispatch(Action::SidebarNext);
+        assert_eq!(app.poll_due_preview_at(now), vec![]);
+        assert_eq!(app.state.preview, Some(a));
+
+        assert_eq!(
+            app.poll_due_preview_at(after_gap()),
+            vec![Effect::Attach(b)]
+        );
+        assert_eq!(app.state.preview, Some(b));
+    }
+
     /// A fast walk down the list attaches to where it stopped, not to every
     /// row it crossed.
     #[test]
@@ -1707,7 +1801,7 @@ mod tests {
         app.dispatch(Action::SidebarNext);
         app.dispatch(Action::SidebarNext);
 
-        let effects = app.poll_due_preview_at(after_debounce());
+        let effects = app.poll_due_preview_at(after_gap());
         assert_eq!(effects, vec![Effect::Attach(b)]);
         assert_eq!(app.state.preview, Some(b));
     }
@@ -1723,7 +1817,7 @@ mod tests {
 
         app.state.sidebar_highlight = Some(SidebarItem::Session(b));
         app.refresh_preview();
-        app.poll_due_preview_at(after_debounce());
+        app.poll_due_preview_at(after_gap());
         assert_eq!(app.state.preview, Some(b));
 
         app.state.sidebar_highlight = Some(SidebarItem::Session(a));
@@ -1743,7 +1837,7 @@ mod tests {
         app.state.focus = Focus::Sidebar;
         app.state.sidebar_highlight = Some(SidebarItem::Session(b));
         app.refresh_preview();
-        app.poll_due_preview_at(after_debounce());
+        app.poll_due_preview_at(after_gap());
 
         app.dispatch(Action::FocusPane(crate::action::Direction::Right));
         assert_eq!(app.state.preview, None);
@@ -1756,7 +1850,7 @@ mod tests {
         let a = Uuid::from_u128(1);
         let mut app = app_with_sessions(&[a]);
         app.dispatch(Action::SidebarNext);
-        app.poll_due_preview_at(after_debounce());
+        app.poll_due_preview_at(after_gap());
         // Stand in for the attach the effect would have opened.
         app.emulators.insert(a, fake_handle());
 
@@ -1775,10 +1869,13 @@ mod tests {
             .map(Uuid::from_u128)
             .collect();
         let mut app = app_with_sessions(&ids);
+        // Each row is previewed in its own gap window, so all of them land.
+        let mut clock = std::time::Instant::now();
         for id in &ids {
             app.state.sidebar_highlight = Some(SidebarItem::Session(*id));
             app.refresh_preview();
-            app.poll_due_preview_at(after_debounce());
+            clock += PREVIEW_GAP + Duration::from_millis(1);
+            app.poll_due_preview_at(clock);
             app.emulators.insert(*id, fake_handle());
         }
 
@@ -1810,6 +1907,7 @@ mod tests {
                 activity_since: chrono::Utc::now(),
                 current_cwd: None,
                 blocked_work: None,
+                last_focused_at: None,
             }],
         });
         app.dispatch(Action::SidebarNext);
@@ -1836,6 +1934,7 @@ mod tests {
             activity_since: Utc::now(),
             current_cwd: None,
             blocked_work: None,
+            last_focused_at: None,
         }
     }
 
@@ -2673,6 +2772,181 @@ mod tests {
         .is_none());
     }
 
+    // -- command bar (#153) -------------------------------------------------
+
+    fn seed_two_sessions(app: &mut App) -> (Uuid, Uuid) {
+        use chrono::Utc;
+        use maestro_protocol::{CatalogEvent, Session, SessionStatus};
+        let make = |n: u128, name: &str, focused: Option<chrono::DateTime<Utc>>| Session {
+            id: Uuid::from_u128(n),
+            command: "bash".into(),
+            cwd: std::path::PathBuf::from("/"),
+            env: Default::default(),
+            metadata: HashMap::from([(
+                "name".to_string(),
+                serde_json::Value::String(name.to_string()),
+            )]),
+            worktree: None,
+            status: SessionStatus::Running,
+            created_at: Utc::now(),
+            foreground: None,
+            activity: Default::default(),
+            activity_detail: None,
+            last_activity_at: Utc::now(),
+            activity_since: Utc::now(),
+            current_cwd: None,
+            blocked_work: None,
+            last_focused_at: focused,
+        };
+        let older = Utc::now() - chrono::Duration::seconds(60);
+        app.catalog.apply_event(CatalogEvent::Snapshot {
+            sessions: vec![
+                make(1, "alpha", Some(older)),
+                make(2, "bravo", Some(Utc::now())),
+            ],
+        });
+        (Uuid::from_u128(1), Uuid::from_u128(2))
+    }
+
+    /// `ctrl-k` is an ordinary keymap entry, bound in both modes so the bar
+    /// opens from the sidebar and from inside a pane (`docs/COMMAND-BAR.md`).
+    #[test]
+    fn ctrl_k_is_bound_to_the_command_bar_in_both_modes() {
+        let app = make_app();
+        assert_eq!(
+            app.cfg.keymap.resolve(Mode::Normal, "ctrl-k"),
+            Some(Action::OpenCommandBar)
+        );
+        assert_eq!(
+            app.cfg.keymap.resolve(Mode::Insert, "ctrl-k"),
+            Some(Action::OpenCommandBar)
+        );
+    }
+
+    /// The help overlay builds its lines from the live keymap, so the bar
+    /// appears there with no second list to maintain.
+    #[test]
+    fn the_help_overlay_lists_the_command_bar() {
+        let app = make_app();
+        let lines = render_help_lines(&app.cfg);
+        assert!(
+            lines
+                .iter()
+                .any(|l| l.contains("ctrl-k") && l.contains("Go to a session")),
+            "{lines:#?}"
+        );
+    }
+
+    #[test]
+    fn opening_the_bar_lists_sessions_most_recently_focused_first() {
+        let mut app = make_app();
+        let (alpha, bravo) = seed_two_sessions(&mut app);
+        app.dispatch(Action::OpenCommandBar);
+        assert_eq!(app.state.overlay(), Some(&OverlayKind::CommandBar));
+        let bar = app.command_bar.as_ref().unwrap();
+        assert_eq!(bar.query(), "");
+        assert_eq!(
+            bar.rows()
+                .iter()
+                .map(|r| match r.target {
+                    BarTarget::Session(id) => id,
+                })
+                .collect::<Vec<_>>(),
+            vec![bravo, alpha]
+        );
+    }
+
+    /// Opening from Insert mode leaves the keyboard where it was, so closing
+    /// gives it back — the bar is a view over the app, not a place in it.
+    #[test]
+    fn opening_from_insert_mode_leaves_focus_and_mode_alone() {
+        let mut app = make_app();
+        seed_two_sessions(&mut app);
+        app.state.attach_to_focused(Uuid::from_u128(1));
+        assert_eq!(
+            (app.state.focus, app.state.mode),
+            (Focus::Pane, Mode::Insert)
+        );
+
+        app.dispatch(Action::OpenCommandBar);
+        assert_eq!(app.state.overlay(), Some(&OverlayKind::CommandBar));
+        assert_eq!(
+            (app.state.focus, app.state.mode),
+            (Focus::Pane, Mode::Insert)
+        );
+
+        let (decision, effects) = app.handle_overlay_input(&InputKey::Esc);
+        assert_eq!(decision, OverlayDecision::Consumed);
+        assert!(effects.is_empty());
+        assert!(app.state.overlay().is_none());
+        assert!(app.command_bar.is_none());
+        assert_eq!(
+            (app.state.focus, app.state.mode),
+            (Focus::Pane, Mode::Insert)
+        );
+    }
+
+    /// Enter goes through the same open path the sidebar's attach uses.
+    #[test]
+    fn enter_attaches_the_highlighted_session() {
+        let mut app = make_app();
+        let (_alpha, bravo) = seed_two_sessions(&mut app);
+        app.dispatch(Action::OpenCommandBar);
+        let (decision, effects) = app.handle_overlay_input(&InputKey::Enter);
+        assert_eq!(decision, OverlayDecision::Consumed);
+        assert_eq!(effects, vec![Effect::Attach(bravo)]);
+        assert!(app.state.overlay().is_none());
+        assert!(app.command_bar.is_none());
+        assert_eq!(app.state.active_session(), Some(bravo));
+    }
+
+    /// Down moves the highlight, so Enter opens the second row instead.
+    #[test]
+    fn the_highlight_moves_before_enter_attaches() {
+        let mut app = make_app();
+        let (alpha, _bravo) = seed_two_sessions(&mut app);
+        app.dispatch(Action::OpenCommandBar);
+        app.handle_overlay_input(&InputKey::Down);
+        let (_, effects) = app.handle_overlay_input(&InputKey::Enter);
+        assert_eq!(effects, vec![Effect::Attach(alpha)]);
+        assert_eq!(app.state.active_session(), Some(alpha));
+    }
+
+    /// Typing goes to the query, not to the keymap: `q` must not quit and `x`
+    /// must not raise a kill confirm while the bar is up.
+    #[test]
+    fn typing_reaches_the_query_rather_than_the_keymap() {
+        let mut app = make_app();
+        seed_two_sessions(&mut app);
+        app.dispatch(Action::OpenCommandBar);
+        for c in "bra".chars() {
+            let (decision, _) = app.handle_overlay_input(&InputKey::Char {
+                c,
+                ctrl: false,
+                alt: false,
+                shift: false,
+            });
+            assert_eq!(decision, OverlayDecision::Consumed);
+        }
+        let bar = app.command_bar.as_ref().unwrap();
+        assert_eq!(bar.query(), "bra");
+        assert_eq!(bar.rows().len(), 1);
+    }
+
+    /// The bar is not previewed into (`docs/PREVIEW.md`): opening discards a
+    /// preview and the highlight behind it raises no new one.
+    #[test]
+    fn opening_the_bar_discards_a_preview() {
+        let mut app = make_app();
+        let (alpha, _bravo) = seed_two_sessions(&mut app);
+        app.state.sidebar_highlight = Some(SidebarItem::Session(alpha));
+        app.state.preview = Some(alpha);
+
+        app.dispatch(Action::OpenCommandBar);
+        assert_eq!(app.state.preview, None);
+        assert_eq!(app.pending_preview, None);
+    }
+
     #[test]
     fn kill_highlighted_opens_confirm() {
         use chrono::Utc;
@@ -2697,6 +2971,7 @@ mod tests {
 
                 current_cwd: None,
                 blocked_work: None,
+                last_focused_at: None,
             }],
         });
         app.dispatch(Action::KillHighlighted);
@@ -2731,6 +3006,7 @@ mod tests {
                 activity_since: Utc::now(),
                 current_cwd: None,
                 blocked_work: None,
+                last_focused_at: None,
             }],
         });
     }

crates/maestro-tui/src/catalog.rs

@@ -222,6 +222,7 @@ mod tests {
             activity_since: chrono::Utc::now(),
             current_cwd: None,
             blocked_work: None,
+            last_focused_at: None,
         }
     }
 

crates/maestro-tui/src/command_bar.rs

@@ -0,0 +1,758 @@
+//! The `ctrl-k` command bar (`docs/COMMAND-BAR.md`): a query line over a
+//! result list, opened from Normal or Insert mode, closed with Escape.
+//!
+//! Sessions are the only kind here (#153); the sigils (#154), the session
+//! action page (#155) and the leader's literal Ctrl-K (#156) land later. The
+//! grouping below is already kind-generic so those slot in without a rewrite.
+//!
+//! Ranking is [`crate::matcher`]'s job and nothing here reorders it — the
+//! groups are a rendering of the ranked list, in the order their best-scoring
+//! member appears. The web bar (`web/src/commandBar.ts`) implements the same
+//! contract; the two must agree.
+
+use maestro_protocol::display::{abbreviate_dir, command_tool, session_tree_path};
+use maestro_protocol::{Session, SessionStatus};
+use ratatui::layout::Rect;
+use ratatui::style::{Modifier, Style};
+use ratatui::text::{Line, Span};
+use ratatui::widgets::{Block, Borders, Clear, Paragraph};
+use ratatui::Frame;
+use uuid::Uuid;
+
+use crate::input::InputKey;
+use crate::matcher::{
+    match_and_rank, CandidateKind, MatchCandidate, MatchFieldName, MatchRange, SessionCandidate,
+};
+use crate::overlays::centered;
+use crate::palette;
+use crate::text_input::TextInput;
+
+/// What Enter on a row does. Only sessions exist today; `>` commands and `~`
+/// directories (#154) become further variants.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum BarTarget {
+    Session(Uuid),
+}
+
+/// One row of the result list, already resolved to what it renders and what it
+/// opens. Headers are labels, not rows, so they are never in this list.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct BarRow {
+    pub kind: CandidateKind,
+    pub target: BarTarget,
+    /// Primary text — the name as the sidebar shows it.
+    pub name: String,
+    /// Secondary text: the field the match was found in when that was not the
+    /// name, so a session found through its directory says so.
+    pub meta: Option<String>,
+    /// The field that won, and the ranges inside it. `None` for an empty
+    /// query, which matches everything and highlights nothing.
+    pub field: Option<MatchFieldName>,
+    pub ranges: Vec<MatchRange>,
+    pub dead: bool,
+}
+
+impl BarRow {
+    /// Whether the highlight belongs on [`Self::meta`] rather than the name.
+    fn meta_is_matched(&self) -> bool {
+        !matches!(self.field, None | Some(MatchFieldName::Name))
+    }
+}
+
+/// One kind's slice of the ranked list, as a header plus the rows under it.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct BarGroup {
+    pub kind: CandidateKind,
+    pub title: &'static str,
+    /// Index of this group's first row in [`CommandBar::rows`].
+    pub start: usize,
+    pub len: usize,
+}
+
+fn kind_title(kind: CandidateKind) -> &'static str {
+    match kind {
+        CandidateKind::Session => "Sessions",
+        CandidateKind::Command => "Commands",
+        CandidateKind::Directory => "Directories",
+    }
+}
+
+/// What a keystroke asked the bar to do.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum BarOutcome {
+    /// The bar stays up.
+    Stay,
+    /// Escape: close and give the keyboard back.
+    Close,
+    /// Enter on a row: close and open what it points at.
+    Open(BarTarget),
+}
+
+/// The empty-query order (`docs/COMMAND-BAR.md`, "Empty query"): most recently
+/// focused first; a session that has never been focused sorts after every
+/// session that has, most recently created first among those; and a dead
+/// session sorts after every live one regardless of recency, because a session
+/// you cannot attach to is not where you just were.
+///
+/// This is also the input order for a non-empty query, which is what the
+/// matcher's last tie-break preserves. Mirrors the web's
+/// `orderSessionsForBar`.
+pub fn order_sessions_for_bar(sessions: &[Session]) -> Vec<&Session> {
+    let mut ordered: Vec<&Session> = sessions.iter().collect();
+    ordered.sort_by(|a, b| {
+        let dead = |s: &Session| u8::from(s.status == SessionStatus::Dead);
+        dead(a)
+            .cmp(&dead(b))
+            .then_with(|| {
+                a.last_focused_at
+                    .is_none()
+                    .cmp(&b.last_focused_at.is_none())
+            })
+            .then_with(|| match (a.last_focused_at, b.last_focused_at) {
+                (Some(x), Some(y)) => y.cmp(&x),
+                _ => std::cmp::Ordering::Equal,
+            })
+            .then_with(|| b.created_at.cmp(&a.created_at))
+    });
+    ordered
+}
+
+/// One session's candidate: the fields `docs/COMMAND-BAR.md`'s candidate table
+/// names, with the directory abbreviated the way the sidebar shows it.
+pub fn session_candidate(session: &Session, home_dir: &str) -> SessionCandidate {
+    SessionCandidate {
+        name: crate::sidebar::name_for(session),
+        directory: session_tree_path(session).map(|path| abbreviate_dir(&path, home_dir)),
+        command: (!session.command.is_empty()).then(|| session.command.clone()),
+        tool: command_tool(&session.command).map(str::to_string),
+    }
+}
+
+/// The bar's state while it is up: the query buffer, the candidates it was
+/// opened over, the rows the current query produces, and the highlight.
+#[derive(Debug)]
+pub struct CommandBar {
+    input: TextInput,
+    /// Matcher input, in the empty-query order. Never reordered — the matcher's
+    /// last tie-break is what keeps that order meaningful.
+    candidates: Vec<MatchCandidate>,
+    /// What each candidate opens, parallel to `candidates`.
+    targets: Vec<BarTarget>,
+    /// Whether each candidate's session is dead, parallel to `candidates`.
+    dead: Vec<bool>,
+    rows: Vec<BarRow>,
+    highlight: usize,
+}
+
+impl CommandBar {
+    /// Open the bar over the sessions the catalog has right now.
+    pub fn new(sessions: &[Session], home_dir: &str) -> Self {
+        let ordered = order_sessions_for_bar(sessions);
+        let candidates = ordered
+            .iter()
+            .map(|s| MatchCandidate::Session(session_candidate(s, home_dir)))
+            .collect();
+        let targets = ordered.iter().map(|s| BarTarget::Session(s.id)).collect();
+        let dead = ordered
+            .iter()
+            .map(|s| s.status == SessionStatus::Dead)
+            .collect();
+        let mut bar = Self {
+            input: TextInput::default(),
+            candidates,
+            targets,
+            dead,
+            rows: Vec::new(),
+            highlight: 0,
+        };
+        bar.recompute();
+        bar
+    }
+
+    pub fn query(&self) -> &str {
+        self.input.value()
+    }
+
+    pub fn rows(&self) -> &[BarRow] {
+        &self.rows
+    }
+
+    pub fn highlight(&self) -> usize {
+        self.highlight
+    }
+
+    /// The row Enter would open.
+    pub fn selected(&self) -> Option<&BarRow> {
+        self.rows.get(self.highlight)
+    }
+
+    /// Group the ranked rows by kind for rendering. Grouping never reorders:
+    /// a group holds its matches in rank order, and groups appear in the order
+    /// their best-scoring member does — so the first row under the first
+    /// header is the globally best result.
+    pub fn groups(&self) -> Vec<BarGroup> {
+        let mut groups: Vec<BarGroup> = Vec::new();
+        for (index, row) in self.rows.iter().enumerate() {
+            match groups.iter_mut().find(|g| g.kind == row.kind) {
+                Some(group) => group.len += 1,
+                None => groups.push(BarGroup {
+                    kind: row.kind,
+                    title: kind_title(row.kind),
+                    start: index,
+                    len: 1,
+                }),
+            }
+        }
+        groups
+    }
+
+    /// Move the highlight. It does not wrap: it stops at the first and last
+    /// row.
+    pub fn move_highlight(&mut self, delta: isize) {
+        if self.rows.is_empty() {
+            self.highlight = 0;
+            return;
+        }
+        let last = self.rows.len() as isize - 1;
+        let next = (self.highlight as isize + delta).clamp(0, last);
+        self.highlight = next as usize;
+    }
+
+    /// Feed the bar a key. Everything the key table (`docs/COMMAND-BAR.md`,
+    /// "Keys") does not claim is ordinary editing.
+    pub fn handle_key(&mut self, key: &InputKey) -> BarOutcome {
+        match key {
+            InputKey::Esc => BarOutcome::Close,
+            InputKey::Enter => match self.selected() {
+                Some(row) => BarOutcome::Open(row.target),
+                // Nothing to open: the bar stays up rather than closing on a
+                // key that did nothing.
+                None => BarOutcome::Stay,
+            },
+            InputKey::Up
+            | InputKey::Char {
+                c: 'p', ctrl: true, ..
+            } => {
+                self.move_highlight(-1);
+                BarOutcome::Stay
+            }
+            InputKey::Down
+            | InputKey::Char {
+                c: 'n', ctrl: true, ..
+            } => {
+                self.move_highlight(1);
+                BarOutcome::Stay
+            }
+            // Tab drills into the highlighted session's action page (#155).
+            // Until then it is inert rather than a literal tab in the query.
+            InputKey::Tab | InputKey::BackTab => BarOutcome::Stay,
+            other => {
+                let before = self.input.value().to_string();
+                self.input.handle_key(other);
+                if self.input.value() != before {
+                    self.recompute();
+                }
+                BarOutcome::Stay
+            }
+        }
+    }
+
+    /// Re-rank for the current query. The highlight starts on the globally
+    /// best row every time the list changes: an old index would point at a
+    /// different result.
+    fn recompute(&mut self) {
+        let rows: Vec<BarRow> = {
+            let results = match_and_rank(self.input.value(), &self.candidates);
+            results
+                .iter()
+                .map(|result| {
+                    let index = self
+                        .candidates
+                        .iter()
+                        .position(|c| std::ptr::eq(c, result.candidate))
+                        .expect("every result borrows one of this bar's candidates");
+                    let MatchCandidate::Session(session) = result.candidate else {
+                        unreachable!("sessions are the only kind the bar builds (#153)")
+                    };
+                    BarRow {
+                        kind: CandidateKind::Session,
+                        target: self.targets[index],
+                        name: session.name.clone(),
+                        meta: meta_text(session, result.field),
+                        field: result.field,
+                        ranges: result.ranges.clone(),
+                        dead: self.dead[index],
+                    }
+                })
+                .collect()
+        };
+        self.rows = rows;
+        self.highlight = 0;
+    }
+
+    /// Draw the bar and return where the terminal cursor belongs.
+    pub fn render(&self, f: &mut Frame, parent: Rect) -> Option<(u16, u16)> {
+        let pal = palette::active();
+        let height = parent.height.saturating_sub(4).clamp(5, 20);
+        let area = centered(parent, 72, height);
+        f.render_widget(Clear, area);
+        let block = Block::default()
+            .title(" go to ")
+            .borders(Borders::ALL)
+            .style(pal.card.base())
+            .border_style(pal.border_style(true));
+        let inner = block.inner(area);
+        f.render_widget(block, area);
+        if inner.height < 3 || inner.width == 0 {
+            return None;
+        }
+        let row = |offset: u16| Rect {
+            x: inner.x,
+            y: inner.y + offset,
+            width: inner.width,
+            height: 1,
+        };
+
+        // Query line, then the results, then the key hint on the last row.
+        let query = row(0);
+        let col = self
+            .input
+            .render(query, f.buffer_mut(), pal.card.text_style());
+        f.render_widget(
+            Paragraph::new(Line::from(Span::styled(
+                "[enter] open   [esc] close",
+                pal.card.dim_style(),
+            ))),
+            row(inner.height - 1),
+        );
+
+        let list_height = inner.height.saturating_sub(2) as usize;
+        if list_height > 0 {
+            for (offset, line) in self.visible_lines(list_height).into_iter().enumerate() {
+                f.render_widget(Paragraph::new(line), row(1 + offset as u16));
+            }
+        }
+        Some((col, query.y))
+    }
+
+    /// The result lines that fit in `height`, scrolled so the highlighted row
+    /// is on screen.
+    fn visible_lines(&self, height: usize) -> Vec<Line<'static>> {
+        let pal = palette::active();
+        if self.rows.is_empty() {
+            return vec![Line::from(Span::styled(
+                "No matches",
+                pal.card.muted_style(),
+            ))];
+        }
+        // Headers and rows, in one list, remembering which line the highlight
+        // sits on so the scroll can keep it visible.
+        let mut lines: Vec<Line<'static>> = Vec::new();
+        let mut highlight_line = 0usize;
+        for group in self.groups() {
+            lines.push(Line::from(Span::styled(
+                group.title.to_string(),
+                pal.group_row_style(),
+            )));
+            for index in group.start..group.start + group.len {
+                if index == self.highlight {
+                    highlight_line = lines.len();
+                }
+                lines.push(self.row_line(index));
+            }
+        }
+        let scroll = highlight_line.saturating_sub(height.saturating_sub(1));
+        lines.into_iter().skip(scroll).take(height).collect()
+    }
+
+    fn row_line(&self, index: usize) -> Line<'static> {
+        let pal = palette::active();
+        let row = &self.rows[index];
+        let selected = index == self.highlight;
+        let surface = pal.surface(selected);
+        let base = if row.dead {
+            surface.dim_style()
+        } else {
+            surface.text_style()
+        };
+        let hit = base.add_modifier(Modifier::BOLD | Modifier::UNDERLINED);
+
+        let mut spans = vec![Span::styled(if selected { "› " } else { "  " }, base)];
+        let name_ranges: &[MatchRange] = if row.meta_is_matched() {
+            &[]
+        } else {
+            &row.ranges
+        };
+        spans.extend(highlighted_spans(&row.name, name_ranges, base, hit));
+        if let Some(meta) = &row.meta {
+            let meta_style = surface.muted_style();
+            let meta_hit = meta_style.add_modifier(Modifier::BOLD | Modifier::UNDERLINED);
+            spans.push(Span::styled("  ", base));
+            let meta_ranges: &[MatchRange] = if row.meta_is_matched() {
+                &row.ranges
+            } else {
+                &[]
+            };
+            spans.extend(highlighted_spans(meta, meta_ranges, meta_style, meta_hit));
+        }
+        Line::from(spans)
+    }
+}
+
+/// The secondary line under a row's name: the field the match was found in
+/// when that was not the name, so a session found through its directory says
+/// so. Mirrors the web's `metaText`.
+fn meta_text(session: &SessionCandidate, field: Option<MatchFieldName>) -> Option<String> {
+    match field {
+        Some(MatchFieldName::Directory) => session.directory.clone(),
+        Some(MatchFieldName::Command) => session.command.clone(),
+        Some(MatchFieldName::Tool) => session.tool.clone(),
+        _ => session.directory.clone(),
+    }
+}
+
+/// Split `text` into styled spans, with the matcher's `[start, end)` character
+/// ranges carrying `hit` and everything else `base`.
+fn highlighted_spans(
+    text: &str,
+    ranges: &[MatchRange],
+    base: Style,
+    hit: Style,
+) -> Vec<Span<'static>> {
+    let chars: Vec<char> = text.chars().collect();
+    let slice = |from: usize, to: usize| -> String {
+        chars[from.min(chars.len())..to.min(chars.len())]
+            .iter()
+            .collect()
+    };
+    let mut spans = Vec::new();
+    let mut cursor = 0usize;
+    for &(start, end) in ranges {
+        if start > cursor {
+            spans.push(Span::styled(slice(cursor, start), base));
+        }
+        spans.push(Span::styled(slice(start, end), hit));
+        cursor = end;
+    }
+    if cursor < chars.len() {
+        spans.push(Span::styled(slice(cursor, chars.len()), base));
+    }
+    spans
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use chrono::{DateTime, TimeZone, Utc};
+    use ratatui::backend::TestBackend;
+    use ratatui::Terminal;
+    use std::collections::HashMap;
+    use std::path::PathBuf;
+
+    fn at(secs: i64) -> DateTime<Utc> {
+        Utc.timestamp_opt(1_700_000_000 + secs, 0).unwrap()
+    }
+
+    fn session(n: u128, command: &str) -> Session {
+        Session {
+            id: Uuid::from_u128(n),
+            cwd: PathBuf::from("/home/me/dev/api"),
+            command: command.to_string(),
+            env: HashMap::new(),
+            metadata: HashMap::new(),
+            worktree: None,
+            status: SessionStatus::Running,
+            created_at: at(0),
+            foreground: None,
+            activity: Default::default(),
+            activity_detail: None,
+            last_activity_at: at(0),
+            activity_since: at(0),
+            current_cwd: None,
+            blocked_work: None,
+            last_focused_at: None,
+        }
+    }
+
+    fn named(n: u128, name: &str) -> Session {
+        let mut s = session(n, "bash");
+        s.metadata
+            .insert("name".into(), serde_json::Value::String(name.to_string()));
+        s
+    }
+
+    fn ids(rows: &[BarRow]) -> Vec<Uuid> {
+        rows.iter()
+            .map(|r| match r.target {
+                BarTarget::Session(id) => id,
+            })
+            .collect()
+    }
+
+    fn typed(bar: &mut CommandBar, text: &str) {
+        for c in text.chars() {
+            bar.handle_key(&InputKey::Char {
+                c,
+                ctrl: false,
+                alt: false,
+                shift: false,
+            });
+        }
+    }
+
+    #[test]
+    fn empty_query_lists_sessions_most_recently_focused_first() {
+        let mut a = named(1, "alpha");
+        a.last_focused_at = Some(at(10));
+        let mut b = named(2, "bravo");
+        b.last_focused_at = Some(at(30));
+        let mut c = named(3, "charlie");
+        c.last_focused_at = Some(at(20));
+
+        let bar = CommandBar::new(&[a, b, c], "/home/me");
+        assert_eq!(
+            ids(bar.rows()),
+            vec![Uuid::from_u128(2), Uuid::from_u128(3), Uuid::from_u128(1)]
+        );
+        // Every row matches with no ranges, so nothing is highlighted inside.
+        assert!(bar.rows().iter().all(|r| r.ranges.is_empty()));
+    }
+
+    #[test]
+    fn never_focused_sessions_sort_after_focused_ones_newest_first() {
+        let mut focused = named(1, "focused");
+        focused.last_focused_at = Some(at(5));
+        let mut older = named(2, "older");
+        older.created_at = at(10);
+        let mut newer = named(3, "newer");
+        newer.created_at = at(20);
+
+        let bar = CommandBar::new(&[older, newer, focused], "/home/me");
+        assert_eq!(
+            ids(bar.rows()),
+            vec![Uuid::from_u128(1), Uuid::from_u128(3), Uuid::from_u128(2)]
+        );
+    }
+
+    /// A session you cannot attach to is not where you just were.
+    #[test]
+    fn dead_sessions_sort_after_live_ones_however_recent() {
+        let mut dead = named(1, "dead");
+        dead.status = SessionStatus::Dead;
+        dead.last_focused_at = Some(at(99));
+        let live = named(2, "live");
+
+        let bar = CommandBar::new(&[dead, live], "/home/me");
+        assert_eq!(
+            ids(bar.rows()),
+            vec![Uuid::from_u128(2), Uuid::from_u128(1)]
+        );
+        assert!(bar.rows()[1].dead);
+    }
+
+    #[test]
+    fn typing_ranks_through_the_matcher_and_returns_ranges() {
+        let mut bar = CommandBar::new(&[named(1, "web-search"), named(2, "websearch")], "/home/me");
+        typed(&mut bar, "ws");
+        // F9: the `s` after `-` earns the boundary bonus.
+        assert_eq!(
+            ids(bar.rows()),
+            vec![Uuid::from_u128(1), Uuid::from_u128(2)]
+        );
+        assert_eq!(bar.rows()[0].ranges, vec![(0, 1), (4, 5)]);
+        assert_eq!(bar.rows()[0].field, Some(MatchFieldName::Name));
+    }
+
+    #[test]
+    fn a_query_matching_nothing_leaves_no_rows() {
+        let mut bar = CommandBar::new(&[named(1, "alpha")], "/home/me");
+        typed(&mut bar, "zzz");
+        assert!(bar.rows().is_empty());
+        assert!(bar.selected().is_none());
+    }
+
+    /// A session found through its directory highlights inside the directory,
+    /// which is also what the row's meta text shows.
+    #[test]
+    fn a_directory_match_highlights_in_the_meta_text() {
+        let mut worker = named(1, "worker");
+        worker.cwd = PathBuf::from("/home/me/dev/api");
+        let mut bar = CommandBar::new(&[worker], "/home/me");
+        typed(&mut bar, "api");
+        assert_eq!(bar.rows()[0].field, Some(MatchFieldName::Directory));
+        assert_eq!(bar.rows()[0].meta.as_deref(), Some("~/dev/api"));
+        assert_eq!(bar.rows()[0].ranges, vec![(6, 9)]);
+    }
+
+    /// The candidate's `tool` is the mark the card's icon stands for, so
+    /// `claude` reaches a session whose name says nothing about it.
+    #[test]
+    fn the_tool_field_is_a_candidate_field() {
+        let mut nameless = named(1, "nameless");
+        nameless.command = "claude --resume".into();
+        let mut bar = CommandBar::new(&[nameless, named(2, "clay")], "/home/me");
+        typed(&mut bar, "claude");
+        assert_eq!(ids(bar.rows()), vec![Uuid::from_u128(1)]);
+        assert_eq!(bar.rows()[0].field, Some(MatchFieldName::Tool));
+    }
+
+    #[test]
+    fn results_group_under_kind_headers_with_the_best_row_first() {
+        let bar = CommandBar::new(&[named(1, "alpha"), named(2, "bravo")], "/home/me");
+        let groups = bar.groups();
+        assert_eq!(groups.len(), 1);
+        assert_eq!(groups[0].title, "Sessions");
+        assert_eq!(groups[0].kind, CandidateKind::Session);
+        assert_eq!((groups[0].start, groups[0].len), (0, 2));
+        // The highlight starts on the globally best row.
+        assert_eq!(bar.highlight(), 0);
+    }
+
+    #[test]
+    fn arrows_and_ctrl_pn_move_the_highlight_without_wrapping() {
+        let mut bar = CommandBar::new(
+            &[named(1, "alpha"), named(2, "bravo"), named(3, "charlie")],
+            "/home/me",
+        );
+        assert_eq!(bar.handle_key(&InputKey::Down), BarOutcome::Stay);
+        assert_eq!(bar.highlight(), 1);
+        bar.handle_key(&InputKey::Char {
+            c: 'n',
+            ctrl: true,
+            alt: false,
+            shift: false,
+        });
+        assert_eq!(bar.highlight(), 2);
+        // Stops at the last row rather than wrapping to the first.
+        bar.handle_key(&InputKey::Down);
+        assert_eq!(bar.highlight(), 2);
+        bar.handle_key(&InputKey::Char {
+            c: 'p',
+            ctrl: true,
+            alt: false,
+            shift: false,
+        });
+        assert_eq!(bar.highlight(), 1);
+        bar.handle_key(&InputKey::Up);
+        bar.handle_key(&InputKey::Up);
+        assert_eq!(bar.highlight(), 0);
+    }
+
+    #[test]
+    fn enter_opens_the_highlighted_session_and_escape_closes() {
+        let mut bar = CommandBar::new(&[named(1, "alpha"), named(2, "bravo")], "/home/me");
+        bar.handle_key(&InputKey::Down);
+        assert_eq!(
+            bar.handle_key(&InputKey::Enter),
+            BarOutcome::Open(BarTarget::Session(Uuid::from_u128(2)))
+        );
+        assert_eq!(bar.handle_key(&InputKey::Esc), BarOutcome::Close);
+    }
+
+    #[test]
+    fn enter_with_no_results_leaves_the_bar_up() {
+        let mut bar = CommandBar::new(&[named(1, "alpha")], "/home/me");
+        typed(&mut bar, "zzz");
+        assert_eq!(bar.handle_key(&InputKey::Enter), BarOutcome::Stay);
+    }
+
+    #[test]
+    fn editing_the_query_re_ranks_and_resets_the_highlight() {
+        let mut bar = CommandBar::new(&[named(1, "alpha"), named(2, "alpine")], "/home/me");
+        bar.handle_key(&InputKey::Down);
+        assert_eq!(bar.highlight(), 1);
+        typed(&mut bar, "alp");
+        assert_eq!(bar.query(), "alp");
+        assert_eq!(bar.highlight(), 0);
+        bar.handle_key(&InputKey::Backspace);
+        assert_eq!(bar.query(), "al");
+        assert_eq!(bar.rows().len(), 2);
+    }
+
+    /// Backspacing back to an empty query is not a special key: the list
+    /// becomes the recency order again.
+    #[test]
+    fn backspacing_to_an_empty_query_restores_the_recency_order() {
+        let mut recent = named(1, "alpha");
+        recent.last_focused_at = Some(at(50));
+        let older = named(2, "alpine");
+        let mut bar = CommandBar::new(&[older, recent], "/home/me");
+        typed(&mut bar, "alpi");
+        assert_eq!(ids(bar.rows()), vec![Uuid::from_u128(2)]);
+        for _ in 0..4 {
+            bar.handle_key(&InputKey::Backspace);
+        }
+        assert_eq!(bar.query(), "");
+        assert_eq!(
+            ids(bar.rows()),
+            vec![Uuid::from_u128(1), Uuid::from_u128(2)]
+        );
+    }
+
+    fn render_to_string(bar: &CommandBar, w: u16, h: u16) -> String {
+        let backend = TestBackend::new(w, h);
+        let mut terminal = Terminal::new(backend).unwrap();
+        terminal
+            .draw(|f| {
+                bar.render(f, f.area());
+            })
+            .unwrap();
+        let buf = terminal.backend().buffer().clone();
+        let mut out = String::new();
+        for y in 0..buf.area.height {
+            for x in 0..buf.area.width {
+                out.push_str(buf[(x, y)].symbol());
+            }
+            out.push('\n');
+        }
+        out
+    }
+
+    #[test]
+    fn renders_the_query_the_headers_and_the_rows() {
+        let mut bar = CommandBar::new(&[named(1, "alpha"), named(2, "alpine")], "/home/me");
+        typed(&mut bar, "alp");
+        let rendered = render_to_string(&bar, 90, 20);
+        assert!(rendered.contains("go to"), "{rendered}");
+        assert!(rendered.contains("alp"), "{rendered}");
+        assert!(rendered.contains("Sessions"), "{rendered}");
+        assert!(rendered.contains("alpha"), "{rendered}");
+        assert!(rendered.contains("alpine"), "{rendered}");
+        assert!(rendered.contains("[esc] close"), "{rendered}");
+    }
+
+    #[test]
+    fn renders_a_no_results_state() {
+        let mut bar = CommandBar::new(&[named(1, "alpha")], "/home/me");
+        typed(&mut bar, "zzz");
+        let rendered = render_to_string(&bar, 90, 20);
+        assert!(rendered.contains("No matches"), "{rendered}");
+    }
+
+    /// The matched characters are drawn bold, so the row shows why it matched.
+    #[test]
+    fn matched_ranges_are_styled_apart_from_the_rest_of_the_row() {
+        let mut bar = CommandBar::new(&[named(1, "web-search")], "/home/me");
+        typed(&mut bar, "ws");
+        let backend = TestBackend::new(90, 20);
+        let mut terminal = Terminal::new(backend).unwrap();
+        terminal
+            .draw(|f| {
+                bar.render(f, f.area());
+            })
+            .unwrap();
+        let buf = terminal.backend().buffer().clone();
+        let mut bold: Vec<String> = Vec::new();
+        for y in 0..buf.area.height {
+            for x in 0..buf.area.width {
+                let cell = &buf[(x, y)];
+                if cell.style().add_modifier.contains(Modifier::BOLD)
+                    && cell.style().add_modifier.contains(Modifier::UNDERLINED)
+                {
+                    bold.push(cell.symbol().to_string());
+                }
+            }
+        }
+        assert_eq!(bold, vec!["w", "s"], "bold cells: {bold:?}");
+    }
+}

crates/maestro-tui/src/config.rs

@@ -65,6 +65,9 @@ const DEFAULT_NORMAL: &[(&str, &str)] = &[
     ("pageup", "ScrollPanePageUp"),
     ("pagedown", "ScrollPanePageDown"),
     // Chrome
+    // The command bar (#153). An ordinary entry, so it is rebindable and the
+    // help overlay picks it up from the live keymap.
+    ("ctrl-k", "OpenCommandBar"),
     ("ctrl-w b", "ToggleSidebar"),
     ("?", "ShowHelp"),
     ("ctrl-w q", "Quit"),
@@ -75,13 +78,17 @@ const DEFAULT_NORMAL: &[(&str, &str)] = &[
     ("mouse:dblclick(sidebar-row)", "AttachHighlighted"),
 ];
 
-/// Default Insert-mode bindings — deliberately empty. Every key typed in
+/// Default Insert-mode bindings — almost empty on purpose. Every key typed in
 /// Insert mode belongs to the session, `esc` included: full-screen apps read
 /// it constantly, so binding it here would make it unreachable. The only way
 /// back to the sidebar is the leader (`LeaveInsert`), which
 /// [`TuiConfig::load`] inserts dynamically so rebinding the leader rebinds
 /// the Insert escape with it.
-const DEFAULT_INSERT: &[(&str, &str)] = &[];
+///
+/// The one exception is the command bar (#153): `ctrl-k` opens it from inside
+/// a pane too, so `docs/COMMAND-BAR.md`'s "from anywhere" holds. Readline's
+/// kill-to-end-of-line is given back through the leader (#156).
+const DEFAULT_INSERT: &[(&str, &str)] = &[("ctrl-k", "OpenCommandBar")];
 
 impl TuiConfig {
     /// Build a runtime config from a [`TuiSection`] (typically the `tui`

crates/maestro-tui/src/lib.rs

@@ -6,6 +6,7 @@ pub mod action;
 pub mod app;
 pub mod catalog;
 pub mod cli;
+pub mod command_bar;
 pub mod config;
 pub mod daemon_link;
 pub mod draft;
@@ -13,6 +14,7 @@ pub mod emulators;
 pub mod fast_forward;
 pub mod input;
 pub mod keymap;
+pub mod matcher;
 pub mod overlays;
 pub mod palette;
 pub mod pane;

crates/maestro-tui/src/matcher.rs

@@ -0,0 +1,750 @@
+//! Pure match-and-rank function for the `ctrl-k` command bar.
+//!
+//! Implements exactly the algorithm in `docs/COMMAND-BAR.md` ("What a
+//! candidate is", "Match and rank", "Fixtures"). Must produce the same order
+//! and scores as `web/src/matcher.ts` for the same input.
+
+use std::collections::HashMap;
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum CandidateKind {
+    Session,
+    Command,
+    Directory,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
+pub enum MatchFieldName {
+    Name,
+    Directory,
+    Command,
+    Tool,
+    Label,
+    Path,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct SessionCandidate {
+    pub name: String,
+    pub directory: Option<String>,
+    pub command: Option<String>,
+    pub tool: Option<String>,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct CommandCandidate {
+    pub label: String,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct DirectoryCandidate {
+    pub path: String,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum MatchCandidate {
+    Session(SessionCandidate),
+    Command(CommandCandidate),
+    Directory(DirectoryCandidate),
+}
+
+pub type MatchRange = (usize, usize);
+
+#[derive(Debug, PartialEq, Eq)]
+pub struct MatchResult<'c> {
+    pub candidate: &'c MatchCandidate,
+    pub score: i32,
+    pub field: Option<MatchFieldName>,
+    pub ranges: Vec<MatchRange>,
+}
+
+struct Field<'c> {
+    name: MatchFieldName,
+    text: &'c str,
+    weight: i32,
+}
+
+impl MatchCandidate {
+    fn kind(&self) -> CandidateKind {
+        match self {
+            MatchCandidate::Session(_) => CandidateKind::Session,
+            MatchCandidate::Command(_) => CandidateKind::Command,
+            MatchCandidate::Directory(_) => CandidateKind::Directory,
+        }
+    }
+
+    fn fields(&self) -> Vec<Field<'_>> {
+        match self {
+            MatchCandidate::Session(session) => {
+                let mut fields = vec![Field {
+                    name: MatchFieldName::Name,
+                    text: &session.name,
+                    weight: 0,
+                }];
+                if let Some(directory) = &session.directory {
+                    fields.push(Field {
+                        name: MatchFieldName::Directory,
+                        text: directory,
+                        weight: -24,
+                    });
+                }
+                if let Some(command) = &session.command {
+                    fields.push(Field {
+                        name: MatchFieldName::Command,
+                        text: command,
+                        weight: -32,
+                    });
+                }
+                if let Some(tool) = &session.tool {
+                    fields.push(Field {
+                        name: MatchFieldName::Tool,
+                        text: tool,
+                        weight: -40,
+                    });
+                }
+                fields
+            }
+            MatchCandidate::Command(command) => vec![Field {
+                name: MatchFieldName::Label,
+                text: &command.label,
+                weight: 0,
+            }],
+            MatchCandidate::Directory(directory) => vec![Field {
+                name: MatchFieldName::Path,
+                text: &directory.path,
+                weight: 0,
+            }],
+        }
+    }
+}
+
+fn kind_order(kind: CandidateKind) -> u8 {
+    match kind {
+        CandidateKind::Session => 0,
+        CandidateKind::Command => 1,
+        CandidateKind::Directory => 2,
+    }
+}
+
+fn lower_char(c: char) -> char {
+    c.to_lowercase().next().unwrap_or(c)
+}
+
+fn lower_chars(chars: &[char]) -> Vec<char> {
+    chars.iter().copied().map(lower_char).collect()
+}
+
+fn normalize_query(query: &str) -> Vec<char> {
+    query
+        .chars()
+        .filter(|c| !c.is_whitespace())
+        .map(lower_char)
+        .collect()
+}
+
+const SEPARATORS: [char; 6] = ['/', '\\', '-', '_', '.', ':'];
+
+fn boundary_bonus(text: &[char], position: usize) -> i32 {
+    if position == 0 {
+        return 18;
+    }
+
+    let previous = text[position - 1];
+    if previous == ' ' || SEPARATORS.contains(&previous) {
+        return 16;
+    }
+
+    let current = text[position];
+    if current.is_uppercase() && previous.is_lowercase() {
+        return 12;
+    }
+
+    let is_digit = current.is_ascii_digit();
+    let previous_is_digit = previous.is_ascii_digit();
+    if is_digit && !previous_is_digit {
+        return 12;
+    }
+
+    0
+}
+
+fn contribution(text: &[char], position: usize, previous_position: isize) -> i32 {
+    let gap = position as isize - previous_position - 1;
+    16 + boundary_bonus(text, position) + if gap == 0 { 8 } else { -gap.min(12) as i32 }
+}
+
+#[derive(Clone)]
+struct Embedding {
+    score: i32,
+    positions: Vec<usize>,
+}
+
+fn is_better_embedding(candidate: &Embedding, incumbent: Option<&Embedding>) -> bool {
+    let Some(incumbent) = incumbent else {
+        return true;
+    };
+    if candidate.score != incumbent.score {
+        return candidate.score > incumbent.score;
+    }
+    for (c, i) in candidate.positions.iter().zip(incumbent.positions.iter()) {
+        if c != i {
+            return c < i;
+        }
+    }
+    false
+}
+
+/// The dynamic program over `(query index, text position)` described in
+/// "Which embedding": greedy leftmost-first matching is insufficient (e.g.
+/// `mtu` against `maestro-tui`), so every reachable position at each query
+/// index carries its best score and position vector forward.
+fn best_embedding(query: &[char], text: &[char]) -> Option<Embedding> {
+    let lower_text = lower_chars(text);
+    let mut previous_states: HashMap<usize, Embedding> = HashMap::new();
+
+    for (query_index, &qc) in query.iter().enumerate() {
+        let mut states: HashMap<usize, Embedding> = HashMap::new();
+
+        for (position, &text_char) in lower_text.iter().enumerate() {
+            if text_char != qc {
+                continue;
+            }
+
+            if query_index == 0 {
+                states.insert(
+                    position,
+                    Embedding {
+                        score: contribution(text, position, -1),
+                        positions: vec![position],
+                    },
+                );
+                continue;
+            }
+
+            for (&previous_position, previous) in previous_states.iter() {
+                if previous_position >= position {
+                    continue;
+                }
+                let mut positions = previous.positions.clone();
+                positions.push(position);
+                let candidate = Embedding {
+                    score: previous.score
+                        + contribution(text, position, previous_position as isize),
+                    positions,
+                };
+                if is_better_embedding(&candidate, states.get(&position)) {
+                    states.insert(position, candidate);
+                }
+            }
+        }
+
+        if states.is_empty() {
+            return None;
+        }
+        previous_states = states;
+    }
+
+    let mut best: Option<Embedding> = None;
+    for embedding in previous_states.into_values() {
+        if is_better_embedding(&embedding, best.as_ref()) {
+            best = Some(embedding);
+        }
+    }
+    best
+}
+
+fn to_ranges(positions: &[usize]) -> Vec<MatchRange> {
+    let mut ranges: Vec<MatchRange> = Vec::new();
+    for &position in positions {
+        if let Some(last) = ranges.last_mut() {
+            if last.1 == position {
+                last.1 = position + 1;
+                continue;
+            }
+        }
+        ranges.push((position, position + 1));
+    }
+    ranges
+}
+
+fn compact(text: &str) -> String {
+    text.chars()
+        .filter(|c| !c.is_whitespace())
+        .map(lower_char)
+        .collect()
+}
+
+struct Ranked<'c> {
+    candidate: &'c MatchCandidate,
+    score: i32,
+    field: Option<MatchFieldName>,
+    ranges: Vec<MatchRange>,
+    matched_text: String,
+    input_index: usize,
+}
+
+/// `(query, candidates) -> ranked subset with matched ranges`. Knows nothing
+/// about sessions, panes or the network — see docs/COMMAND-BAR.md.
+pub fn match_and_rank<'c>(query: &str, candidates: &'c [MatchCandidate]) -> Vec<MatchResult<'c>> {
+    let normalized_query = normalize_query(query);
+
+    if normalized_query.is_empty() {
+        return candidates
+            .iter()
+            .map(|candidate| MatchResult {
+                candidate,
+                score: 0,
+                field: None,
+                ranges: Vec::new(),
+            })
+            .collect();
+    }
+
+    let mut results: Vec<Ranked<'c>> = Vec::new();
+
+    for (input_index, candidate) in candidates.iter().enumerate() {
+        let mut best: Option<(MatchFieldName, &str, i32, Vec<usize>)> = None;
+
+        for field in candidate.fields() {
+            let text_chars: Vec<char> = field.text.chars().collect();
+            let Some(embedding) = best_embedding(&normalized_query, &text_chars) else {
+                continue;
+            };
+
+            let compact_text = compact(field.text);
+            let normalized_query_str: String = normalized_query.iter().collect();
+            let adjustment = if compact_text == normalized_query_str {
+                64
+            } else if compact_text.starts_with(&normalized_query_str) {
+                32
+            } else {
+                0
+            };
+            let score = embedding.score + adjustment + field.weight;
+
+            let is_better = match &best {
+                None => true,
+                Some((_, _, best_score, _)) => score > *best_score,
+            };
+            if is_better {
+                best = Some((field.name, field.text, score, embedding.positions));
+            }
+        }
+
+        if let Some((field_name, field_text, score, positions)) = best {
+            results.push(Ranked {
+                candidate,
+                score,
+                field: Some(field_name),
+                ranges: to_ranges(&positions),
+                matched_text: field_text.to_string(),
+                input_index,
+            });
+        }
+    }
+
+    results.sort_by(|a, b| {
+        b.score
+            .cmp(&a.score)
+            .then_with(|| kind_order(a.candidate.kind()).cmp(&kind_order(b.candidate.kind())))
+            .then_with(|| {
+                a.matched_text
+                    .chars()
+                    .count()
+                    .cmp(&b.matched_text.chars().count())
+            })
+            .then_with(|| a.matched_text.cmp(&b.matched_text))
+            .then_with(|| a.input_index.cmp(&b.input_index))
+    });
+
+    results
+        .into_iter()
+        .map(|ranked| MatchResult {
+            candidate: ranked.candidate,
+            score: ranked.score,
+            field: ranked.field,
+            ranges: ranked.ranges,
+        })
+        .collect()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn session(
+        name: &str,
+        directory: Option<&str>,
+        command: Option<&str>,
+        tool: Option<&str>,
+    ) -> MatchCandidate {
+        MatchCandidate::Session(SessionCandidate {
+            name: name.to_string(),
+            directory: directory.map(str::to_string),
+            command: command.map(str::to_string),
+            tool: tool.map(str::to_string),
+        })
+    }
+
+    fn command(label: &str) -> MatchCandidate {
+        MatchCandidate::Command(CommandCandidate {
+            label: label.to_string(),
+        })
+    }
+
+    fn directory(path: &str) -> MatchCandidate {
+        MatchCandidate::Directory(DirectoryCandidate {
+            path: path.to_string(),
+        })
+    }
+
+    fn label(candidate: &MatchCandidate) -> String {
+        match candidate {
+            MatchCandidate::Session(s) => format!("session:{}", s.name),
+            MatchCandidate::Command(c) => format!("command:{}", c.label),
+            MatchCandidate::Directory(d) => format!("directory:{}", d.path),
+        }
+    }
+
+    fn positions(result: &MatchResult) -> Vec<usize> {
+        result
+            .ranges
+            .iter()
+            .flat_map(|&(start, end)| start..end)
+            .collect()
+    }
+
+    #[allow(clippy::type_complexity)]
+    fn expect_results(
+        query: &str,
+        candidates: &[MatchCandidate],
+        expected: &[(&str, i32, Option<MatchFieldName>, &[usize])],
+    ) {
+        let results = match_and_rank(query, candidates);
+
+        let actual: Vec<(String, i32)> = results
+            .iter()
+            .map(|r| (label(r.candidate), r.score))
+            .collect();
+        let expected_labels: Vec<(String, i32)> = expected
+            .iter()
+            .map(|(l, s, _, _)| (l.to_string(), *s))
+            .collect();
+        assert_eq!(actual, expected_labels, "order/scores for query {query:?}");
+
+        let actual_fields: Vec<Option<MatchFieldName>> = results.iter().map(|r| r.field).collect();
+        let expected_fields: Vec<Option<MatchFieldName>> =
+            expected.iter().map(|(_, _, f, _)| *f).collect();
+        assert_eq!(actual_fields, expected_fields, "fields for query {query:?}");
+
+        let actual_positions: Vec<Vec<usize>> = results.iter().map(positions).collect();
+        let expected_positions: Vec<Vec<usize>> =
+            expected.iter().map(|(_, _, _, p)| p.to_vec()).collect();
+        assert_eq!(
+            actual_positions, expected_positions,
+            "positions for query {query:?}"
+        );
+    }
+
+    #[test]
+    fn f1_empty_query_keeps_input_order() {
+        expect_results(
+            "",
+            &[
+                session("kill", Some("~/dev/api"), Some("bash"), None),
+                session(
+                    "killer-app",
+                    Some("~/dev/killer-app"),
+                    Some("claude --resume"),
+                    Some("claude"),
+                ),
+                command("Kill selected session"),
+            ],
+            &[
+                ("session:kill", 0, None, &[]),
+                ("session:killer-app", 0, None, &[]),
+                ("command:Kill selected session", 0, None, &[]),
+            ],
+        );
+    }
+
+    #[test]
+    fn f2_exact_session_name_beats_prefix_kind_breaks_tie() {
+        expect_results(
+            "kill",
+            &[
+                session("kill", Some("~/dev/api"), Some("bash"), None),
+                session(
+                    "killer-app",
+                    Some("~/dev/killer-app"),
+                    Some("claude --resume"),
+                    Some("claude"),
+                ),
+                command("Kill selected session"),
+            ],
+            &[
+                (
+                    "session:kill",
+                    178,
+                    Some(MatchFieldName::Name),
+                    &[0, 1, 2, 3],
+                ),
+                (
+                    "session:killer-app",
+                    146,
+                    Some(MatchFieldName::Name),
+                    &[0, 1, 2, 3],
+                ),
+                (
+                    "command:Kill selected session",
+                    146,
+                    Some(MatchFieldName::Label),
+                    &[0, 1, 2, 3],
+                ),
+            ],
+        );
+    }
+
+    #[test]
+    fn f3_path_segment_boundaries_beat_mid_segment() {
+        expect_results(
+            "foo",
+            &[
+                directory("~/dev/foobar"),
+                directory("~/src/myfoo"),
+                directory("~/foo"),
+            ],
+            &[
+                (
+                    "directory:~/foo",
+                    78,
+                    Some(MatchFieldName::Path),
+                    &[2, 3, 4],
+                ),
+                (
+                    "directory:~/dev/foobar",
+                    74,
+                    Some(MatchFieldName::Path),
+                    &[6, 7, 8],
+                ),
+                (
+                    "directory:~/src/myfoo",
+                    56,
+                    Some(MatchFieldName::Path),
+                    &[8, 9, 10],
+                ),
+            ],
+        );
+    }
+
+    #[test]
+    fn f4_no_match_returns_empty() {
+        expect_results(
+            "zzz",
+            &[
+                session("kill", Some("~/dev/api"), Some("bash"), None),
+                command("Kill selected session"),
+            ],
+            &[],
+        );
+    }
+
+    #[test]
+    fn f5_highest_scoring_embedding_beats_greedy() {
+        expect_results(
+            "mtu",
+            &[
+                session("maestro-tui", None, None, None),
+                session("maestro-daemon", None, None, None),
+                session("mtui-scratch", None, None, None),
+            ],
+            &[
+                (
+                    "session:mtui-scratch",
+                    122,
+                    Some(MatchFieldName::Name),
+                    &[0, 1, 2],
+                ),
+                (
+                    "session:maestro-tui",
+                    91,
+                    Some(MatchFieldName::Name),
+                    &[0, 8, 9],
+                ),
+            ],
+        );
+    }
+
+    #[test]
+    fn f6_name_beats_weighted_directory() {
+        expect_results(
+            "api",
+            &[
+                session("api", Some("~/dev/web"), Some("bash"), None),
+                session("worker", Some("~/dev/api"), Some("bash"), None),
+            ],
+            &[
+                ("session:api", 154, Some(MatchFieldName::Name), &[0, 1, 2]),
+                (
+                    "session:worker",
+                    50,
+                    Some(MatchFieldName::Directory),
+                    &[6, 7, 8],
+                ),
+            ],
+        );
+    }
+
+    #[test]
+    fn f7_case_insensitive_length_breaks_tie() {
+        expect_results(
+            "api",
+            &[
+                session("API-Gateway", None, None, None),
+                session("apiary", None, None, None),
+            ],
+            &[
+                (
+                    "session:apiary",
+                    122,
+                    Some(MatchFieldName::Name),
+                    &[0, 1, 2],
+                ),
+                (
+                    "session:API-Gateway",
+                    122,
+                    Some(MatchFieldName::Name),
+                    &[0, 1, 2],
+                ),
+            ],
+        );
+    }
+
+    #[test]
+    fn f8_exact_tool_beats_command_field() {
+        expect_results(
+            "claude",
+            &[
+                session(
+                    "nameless",
+                    Some("~/dev/x"),
+                    Some("claude --resume"),
+                    Some("claude"),
+                ),
+                session("clay", Some("~/dev/y"), Some("bash"), None),
+            ],
+            &[(
+                "session:nameless",
+                186,
+                Some(MatchFieldName::Tool),
+                &[0, 1, 2, 3, 4, 5],
+            )],
+        );
+    }
+
+    #[test]
+    fn f9_separator_earns_word_boundary_bonus() {
+        expect_results(
+            "ws",
+            &[
+                session("websearch", None, None, None),
+                session("web-search", None, None, None),
+            ],
+            &[
+                (
+                    "session:web-search",
+                    71,
+                    Some(MatchFieldName::Name),
+                    &[0, 4],
+                ),
+                ("session:websearch", 56, Some(MatchFieldName::Name), &[0, 3]),
+            ],
+        );
+    }
+
+    #[test]
+    fn f10_command_labels_rank_by_boundary_and_gap() {
+        expect_results(
+            "se",
+            &[
+                command("Kill selected session"),
+                command("Create a session"),
+                command("Show help"),
+            ],
+            &[
+                (
+                    "command:Show help",
+                    53,
+                    Some(MatchFieldName::Label),
+                    &[0, 6],
+                ),
+                (
+                    "command:Kill selected session",
+                    51,
+                    Some(MatchFieldName::Label),
+                    &[5, 6],
+                ),
+                (
+                    "command:Create a session",
+                    47,
+                    Some(MatchFieldName::Label),
+                    &[9, 10],
+                ),
+            ],
+        );
+    }
+
+    #[test]
+    fn f11_directory_matches_separate_on_initial_gap() {
+        expect_results(
+            "dev",
+            &[
+                session("api", Some("~/dev/api"), Some("bash"), None),
+                session("notes", Some("~/documents/dev-notes"), Some("nvim"), None),
+                session("scratch", Some("~/srv/devops"), Some("bash"), None),
+            ],
+            &[
+                (
+                    "session:api",
+                    54,
+                    Some(MatchFieldName::Directory),
+                    &[2, 3, 4],
+                ),
+                (
+                    "session:scratch",
+                    50,
+                    Some(MatchFieldName::Directory),
+                    &[6, 7, 8],
+                ),
+                (
+                    "session:notes",
+                    44,
+                    Some(MatchFieldName::Directory),
+                    &[12, 13, 14],
+                ),
+            ],
+        );
+    }
+
+    #[test]
+    fn f12_exact_beats_prefix() {
+        expect_results(
+            "quit",
+            &[command("Quit Maestro"), command("Quit")],
+            &[
+                (
+                    "command:Quit",
+                    178,
+                    Some(MatchFieldName::Label),
+                    &[0, 1, 2, 3],
+                ),
+                (
+                    "command:Quit Maestro",
+                    146,
+                    Some(MatchFieldName::Label),
+                    &[0, 1, 2, 3],
+                ),
+            ],
+        );
+    }
+}

crates/maestro-tui/src/palette.rs

@@ -813,6 +813,21 @@ impl Palette {
         }
     }
 
+    /// Background for the card whose session the pane is showing
+    /// (`docs/SIDEBAR.md`). It sits partway from the card surface to the
+    /// selection surface, so the sidebar reads as one ladder: unfilled, half
+    /// filled for the session in the pane, fully filled under the cursor.
+    ///
+    /// Blended rather than added as a third `Surface` — a new surface means
+    /// eight more colours hand-picked seventeen times — which is also why it
+    /// borrows the *selection* surface's foregrounds: those are the ones
+    /// already picked for a filled row. A preset whose colours the terminal
+    /// owns (`ansi`) has nothing to blend, so it keeps the card background and
+    /// says "in the pane" with the filled glyph alone.
+    pub fn pane_row_bg(&self) -> Color {
+        mix(self.card.bg, self.selection.bg, 0.55)
+    }
+
     /// Border style for a panel, by whether it holds focus.
     pub fn border_style(&self, focused: bool) -> Style {
         if focused {
@@ -873,6 +888,16 @@ pub fn active() -> Palette {
     *active_slot().read().expect("active palette lock poisoned")
 }
 
+/// Blend `amount` of `to` into `from`, in plain sRGB. Both must be RGB, or
+/// there is nothing to blend and `from` comes back unchanged.
+fn mix(from: Color, to: Color, amount: f64) -> Color {
+    let (Color::Rgb(fr, fg, fb), Color::Rgb(tr, tg, tb)) = (from, to) else {
+        return from;
+    };
+    let lerp = |a: u8, b: u8| (a as f64 + (b as f64 - a as f64) * amount).round() as u8;
+    Color::Rgb(lerp(fr, tr), lerp(fg, tg), lerp(fb, tb))
+}
+
 /// WCAG relative luminance of an RGB role. Non-RGB colours have no fixed
 /// luminance — they are whatever the terminal theme says — so they return
 /// `None` and cannot be contrast-checked.
@@ -937,6 +962,43 @@ mod tests {
         }
     }
 
+    /// The pane row is the middle rung: a visible fill against the card, still
+    /// a different surface from the cursor's, and carrying the selection
+    /// surface's foregrounds, which it borrows rather than shipping its own.
+    #[test]
+    fn the_pane_row_is_a_rung_between_the_card_and_the_selection() {
+        for (preset, p) in rgb_presets() {
+            let bg = p.pane_row_bg();
+            let from_card = contrast_ratio(p.card.bg, bg)
+                .unwrap_or_else(|| panic!("{preset}.pane_row_bg must be RGB"));
+            assert!(
+                from_card >= 1.15,
+                "{preset}: pane row {from_card:.2} from the card background is not a visible fill"
+            );
+            let from_selection =
+                contrast_ratio(p.selection.bg, bg).expect("selection.bg must be RGB");
+            assert!(
+                from_selection >= 1.15,
+                "{preset}: pane row {from_selection:.2} from the cursor's fill —                  the highlight would vanish on the session already in the pane"
+            );
+            for (role, color) in p.selection.roles() {
+                let ratio = contrast_ratio(bg, color).expect("selection role must be RGB");
+                let floor = if role == "dim" { 3.0 } else { 4.5 };
+                assert!(
+                    ratio >= floor,
+                    "{preset}.selection.{role} on the pane row is {ratio:.2}, below {floor}"
+                );
+            }
+        }
+    }
+
+    /// A preset the terminal themes has nothing to blend from.
+    #[test]
+    fn ansi_keeps_the_card_background_for_the_pane_row() {
+        let p = Palette::ANSI;
+        assert_eq!(p.pane_row_bg(), p.card.bg);
+    }
+
     #[test]
     fn every_preset_supplies_every_role() {
         for (name, p) in Palette::presets() {

crates/maestro-tui/src/render.rs

@@ -86,6 +86,9 @@ pub struct RenderInputs<'a> {
     pub help: &'a HelpOverlay,
     /// Edit buffer behind the rename prompt (#125).
     pub rename_input: &'a crate::text_input::TextInput,
+    /// The command bar behind [`OverlayKind::CommandBar`] (#153), when one is
+    /// up.
+    pub command_bar: Option<&'a crate::command_bar::CommandBar>,
     /// Liveness + release of the daemon, for the status bar's indicator and the
     /// restart overlay (`docs/RESTART.md`).
     pub link: &'a crate::daemon_link::LinkStatus,
@@ -198,6 +201,14 @@ pub fn draw(f: &mut Frame, inputs: RenderInputs<'_>) -> RegionMap {
             }
             map.modal = Some(area);
         }
+        Some(OverlayKind::CommandBar) => {
+            if let Some(bar) = inputs.command_bar {
+                if let Some((x, y)) = bar.render(f, area) {
+                    f.set_cursor_position((x, y));
+                }
+                map.modal = Some(area);
+            }
+        }
         Some(OverlayKind::Help) => {
             inputs.help.render(f, area);
             map.modal = Some(area);
@@ -415,6 +426,7 @@ mod tests {
             sessions: Vec::new(),
             highlight: None,
             attached: HashSet::new(),
+            pane_session: None,
         };
         let help = HelpOverlay { lines: Vec::new() };
         let state = AppState::new();
@@ -427,6 +439,7 @@ mod tests {
             state: &state,
             help: &help,
             rename_input: &crate::text_input::TextInput::default(),
+            command_bar: None,
             link,
         };
         let backend = ratatui::backend::TestBackend::new(120, 24);
@@ -511,6 +524,7 @@ mod tests {
             sessions: Vec::new(),
             highlight: None,
             attached: HashSet::new(),
+            pane_session: None,
         };
         let help = HelpOverlay { lines: Vec::new() };
         let inputs = RenderInputs {
@@ -522,6 +536,7 @@ mod tests {
             state: &state,
             help: &help,
             rename_input: &crate::text_input::TextInput::default(),
+            command_bar: None,
             link: &online_link(),
         };
 
@@ -561,6 +576,7 @@ mod tests {
             sessions: Vec::new(),
             highlight: None,
             attached: HashSet::new(),
+            pane_session: None,
         };
         let help = HelpOverlay { lines: Vec::new() };
         let draw_map = |focus| {
@@ -575,6 +591,7 @@ mod tests {
                 state: &state,
                 help: &help,
                 rename_input: &crate::text_input::TextInput::default(),
+                command_bar: None,
                 link: &online_link(),
             };
             let backend = ratatui::backend::TestBackend::new(80, 24);
@@ -601,6 +618,7 @@ mod tests {
             sessions: Vec::new(),
             highlight: None,
             attached: HashSet::new(),
+            pane_session: None,
         };
         let help = HelpOverlay { lines: Vec::new() };
         let render = |focus| {
@@ -615,6 +633,7 @@ mod tests {
                 state: &state,
                 help: &help,
                 rename_input: &crate::text_input::TextInput::default(),
+                command_bar: None,
                 link: &online_link(),
             };
             let backend = ratatui::backend::TestBackend::new(80, 24);

crates/maestro-tui/src/sidebar.rs

@@ -37,14 +37,39 @@ const META_INDENT: &str = "    ";
 /// both card rows, replacing the old inline dot glyph on the meta line.
 const RAIL: &str = "▌";
 
-/// Cards use the selection surface only while the sidebar owns focus. An
+/// Which fill a session card wears (docs/SIDEBAR.md). The cursor's fill wins
+/// on its own row: a highlight that lands on the session already in the pane
+/// still has to be visible.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+enum CardFill {
+    /// An ordinary card, on the card surface.
+    None,
+    /// The session the pane is showing.
+    Pane,
+    /// Under the cursor, with the sidebar holding the keyboard.
+    Cursor,
+}
+
+impl CardFill {
+    /// Both filled tiers carry the selection surface's foregrounds — those are
+    /// the colours picked for a filled row, and a colour chosen for the card
+    /// background is not legible on one.
+    fn filled(self) -> bool {
+        self != CardFill::None
+    }
+}
+
+/// Cards take the cursor's fill only while the sidebar owns focus. An
 /// unfocused highlight remains an edge-marked cursor without claiming the
 /// keyboard via a filled selection background.
-fn card_base(highlighted: bool, focused: bool) -> Style {
+fn card_base(fill: CardFill, focused: bool) -> Style {
     let palette = palette::active();
-    let mut style = palette.surface(highlighted && focused).text_style();
-    if focused && !highlighted {
-        style = style.bg(palette.sidebar_focus_bg);
+    let mut style = palette.surface(fill.filled()).text_style();
+    match fill {
+        CardFill::Cursor => {}
+        CardFill::Pane => style = style.bg(palette.pane_row_bg()),
+        CardFill::None if focused => style = style.bg(palette.sidebar_focus_bg),
+        CardFill::None => {}
     }
     style
 }
@@ -55,6 +80,9 @@ pub struct Sidebar {
     pub sessions: Vec<Session>,
     pub highlight: Option<SidebarItem>,
     pub attached: HashSet<Uuid>,
+    /// The session the active tab's pane is showing. It wears a fill of its
+    /// own, so "in the pane" is not carried by the ● glyph alone.
+    pub pane_session: Option<Uuid>,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -113,8 +141,7 @@ impl Sidebar {
             lines.push(Line::from(self.group_row(&group, width, focused, home)));
             if !group.collapsed {
                 for s in &group.sessions {
-                    let highlighted = self.highlight == Some(SidebarItem::Session(s.id));
-                    let base = card_base(highlighted, focused);
+                    let base = card_base(self.card_fill(s, focused), focused);
                     lines.push(Line::from(self.name_row(s, width, focused)));
                     let meta = self.meta_row(s, width, focused);
                     lines.push(Line::from(pad_to_width(meta, width, base)));
@@ -226,6 +253,18 @@ impl Sidebar {
         pad_to_width(spans, width, base)
     }
 
+    /// Which fill this session's card wears. The cursor wins on its own row,
+    /// so a highlight parked on the session already in the pane stays visible.
+    fn card_fill(&self, s: &Session, focused: bool) -> CardFill {
+        if focused && self.highlight == Some(SidebarItem::Session(s.id)) {
+            CardFill::Cursor
+        } else if self.pane_session == Some(s.id) {
+            CardFill::Pane
+        } else {
+            CardFill::None
+        }
+    }
+
     fn name_row(&self, s: &Session, width: usize, focused: bool) -> Vec<Span<'static>> {
         let glyph = match (s.status, self.attached.contains(&s.id)) {
             (SessionStatus::Dead, _) => "✗",
@@ -233,12 +272,13 @@ impl Sidebar {
             (SessionStatus::Running, false) => "○",
         };
         let highlighted = self.highlight == Some(SidebarItem::Session(s.id));
-        let base = card_base(highlighted, focused);
+        let fill = self.card_fill(s, focused);
+        let base = card_base(fill, focused);
         let prefix = 1 + INDENT.chars().count() + 2;
         let name_budget = width.saturating_sub(prefix);
 
         let edge = highlighted && !focused;
-        let rail_style = base.fg(activity_color(s.activity, highlighted, focused));
+        let rail_style = base.fg(activity_color(s.activity, fill));
         let mut spans: Vec<Span<'static>> = vec![
             Span::styled(RAIL, rail_style),
             Span::styled(
@@ -257,7 +297,7 @@ impl Sidebar {
         let name_style = if maestro_protocol::display::is_provisional_name(s) {
             base.patch(
                 palette::active()
-                    .surface(highlighted && focused)
+                    .surface(fill.filled())
                     .muted_style()
                     .bg(base.bg.unwrap_or(palette::active().chrome_bg)),
             )
@@ -283,11 +323,11 @@ impl Sidebar {
         let blocked = s.blocked_work.filter(|b| !b.is_clear());
         let dead = s.status == SessionStatus::Dead;
         let highlighted = self.highlight == Some(SidebarItem::Session(s.id));
-        let base = card_base(highlighted, focused);
-        let rail_style =
-            base.patch(Style::default().fg(activity_color(s.activity, highlighted, focused)));
+        let fill = self.card_fill(s, focused);
+        let base = card_base(fill, focused);
+        let rail_style = base.patch(Style::default().fg(activity_color(s.activity, fill)));
         let muted = palette::active()
-            .surface(highlighted && focused)
+            .surface(fill.filled())
             .muted_style()
             .bg(base.bg.unwrap_or(palette::active().chrome_bg));
         let edge = highlighted && !focused;
@@ -308,7 +348,7 @@ impl Sidebar {
         let mut tail: Vec<Span<'static>> = Vec::new();
         if let Some(b) = blocked {
             let palette = palette::active();
-            let surface = palette.surface(highlighted && focused);
+            let surface = palette.surface(fill.filled());
             for (kind, text) in b.stats() {
                 let style = match kind {
                     StatKind::Added => muted.fg(surface.active),
@@ -352,10 +392,8 @@ impl Sidebar {
 /// state word is never spelled out — this colour carries it. The highlighted
 /// card takes its state colours from the selection surface: a colour picked
 /// for the dark card background is not legible on the selection background.
-fn activity_color(state: ActivityState, highlighted: bool, focused: bool) -> Color {
-    palette::active()
-        .surface(highlighted && focused)
-        .activity(state)
+fn activity_color(state: ActivityState, fill: CardFill) -> Color {
+    palette::active().surface(fill.filled()).activity(state)
 }
 
 /// docs/SIDEBAR.md duration format — floored whole seconds / minutes / hours,
@@ -461,6 +499,7 @@ mod tests {
             activity_since: Utc::now(),
             current_cwd: None,
             blocked_work: None,
+            last_focused_at: None,
         }
     }
 
@@ -520,6 +559,7 @@ mod tests {
             sessions: vec![session_named(1, "claude"), session_named(2, "bash")],
             highlight: None,
             attached: Default::default(),
+            pane_session: None,
         };
         let rendered = render_to_string(&draw(&sb, 28, 12));
         assert!(
@@ -544,6 +584,7 @@ mod tests {
             sessions: vec![s],
             highlight: None,
             attached: Default::default(),
+            pane_session: None,
         })
         .groups(&HashSet::new());
         assert_eq!(groups[0].key, PathBuf::from("/home/u/repos/maestro"));
@@ -555,6 +596,7 @@ mod tests {
             sessions: Vec::new(),
             highlight: None,
             attached: Default::default(),
+            pane_session: None,
         };
         assert!(sidebar.groups(&HashSet::new()).is_empty());
         assert!(sidebar.rendered_items().is_empty());
@@ -566,6 +608,7 @@ mod tests {
             sessions: vec![session_named(1, "claude"), session_named(2, "bash")],
             highlight: None,
             attached: Default::default(),
+            pane_session: None,
         };
         let key = PathBuf::from("/tmp");
         let mut collapsed = HashSet::new();
@@ -590,6 +633,7 @@ mod tests {
             sessions: vec![session],
             highlight: None,
             attached: Default::default(),
+            pane_session: None,
         };
         let key = PathBuf::from("/very/long/project/path/extraordinarily-long-project-name");
         let collapsed = HashSet::from([key]);
@@ -620,6 +664,7 @@ mod tests {
             sessions: vec![session_named(1, "claude")],
             highlight: None,
             attached: Default::default(),
+            pane_session: None,
         };
         let all = rows(&draw(&sidebar, 40, 8));
         assert!(all[1].contains("/tmp"));
@@ -635,6 +680,7 @@ mod tests {
             sessions: vec![session_named(1, "claude")],
             highlight: None,
             attached: [sid].into_iter().collect(),
+            pane_session: None,
         };
         let all = rows(&draw(&sb, 28, 6));
         let line = row_containing(&all, "claude");
@@ -645,6 +691,87 @@ mod tests {
         );
     }
 
+    /// Whether any cell in the buffer is painted on `bg`.
+    fn any_cell_on(buf: &Buffer, bg: Color) -> bool {
+        (0..buf.area.height)
+            .any(|y| (0..buf.area.width).any(|x| buf[(x, y)].style().bg == Some(bg)))
+    }
+
+    /// docs/SIDEBAR.md: the session the pane is showing wears a fill, so it is
+    /// not the ● glyph alone carrying "this is the one on screen".
+    #[test]
+    fn the_session_in_the_pane_wears_the_pane_fill() {
+        let sid = Uuid::from_u128(1);
+        let p = palette::active();
+        let sb = Sidebar {
+            sessions: vec![session_named(1, "claude")],
+            highlight: None,
+            attached: [sid].into_iter().collect(),
+            pane_session: Some(sid),
+        };
+        assert!(any_cell_on(&draw(&sb, 28, 6), p.pane_row_bg()));
+
+        let none = Sidebar {
+            pane_session: None,
+            ..sb
+        };
+        assert!(!any_cell_on(&draw(&none, 28, 6), p.pane_row_bg()));
+    }
+
+    /// The cursor's fill wins on its own row: a highlight that lands on the
+    /// session already in the pane has to stay visible.
+    #[test]
+    fn the_cursor_outranks_the_pane_fill_on_its_own_row() {
+        let sid = Uuid::from_u128(1);
+        let p = palette::active();
+        let sb = Sidebar {
+            sessions: vec![session_named(1, "claude")],
+            highlight: Some(SidebarItem::Session(sid)),
+            attached: [sid].into_iter().collect(),
+            pane_session: Some(sid),
+        };
+        let buf = draw_with_focus(&sb, 28, 6, true);
+        assert!(any_cell_on(&buf, p.selection.bg), "cursor fill is missing");
+        assert!(
+            !any_cell_on(&buf, p.pane_row_bg()),
+            "the pane fill is showing through the cursor's own row"
+        );
+    }
+
+    /// A card the pane is showing is a filled row, so it takes the selection
+    /// surface's foregrounds — a colour picked for the card background is not
+    /// legible on a fill.
+    #[test]
+    fn the_pane_row_carries_selection_foregrounds() {
+        let sid = Uuid::from_u128(1);
+        let p = palette::active();
+        let mut sess = session_named(1, "claude");
+        sess.activity = ActivityState::AwaitingInput;
+        let sb = Sidebar {
+            sessions: vec![sess],
+            highlight: None,
+            attached: [sid].into_iter().collect(),
+            pane_session: Some(sid),
+        };
+        let buf = draw(&sb, 28, 6);
+        let on_pane_row = |fg: Color| {
+            (0..buf.area.height).any(|y| {
+                (0..buf.area.width).any(|x| {
+                    let st = buf[(x, y)].style();
+                    st.bg == Some(p.pane_row_bg()) && st.fg == Some(fg)
+                })
+            })
+        };
+        assert!(
+            on_pane_row(p.selection.activity(ActivityState::AwaitingInput)),
+            "the rail must carry the state in the filled surface's colours"
+        );
+        assert!(
+            !on_pane_row(p.card.activity(ActivityState::AwaitingInput)),
+            "a card surface colour is painted onto the pane fill"
+        );
+    }
+
     #[test]
     fn dead_session_uses_cross_glyph() {
         let mut sess = session_named(1, "claude");
@@ -653,6 +780,7 @@ mod tests {
             sessions: vec![sess],
             highlight: None,
             attached: Default::default(),
+            pane_session: None,
         };
         let buf = draw(&sb, 28, 6);
         let all = rows(&buf);
@@ -681,6 +809,7 @@ mod tests {
             sessions: vec![blocked, clear, unprobed],
             highlight: None,
             attached: Default::default(),
+            pane_session: None,
         };
         let all = rows(&draw(&sb, 44, 10));
 
@@ -727,6 +856,7 @@ mod tests {
             sessions: vec![generated, settled],
             highlight: None,
             attached: Default::default(),
+            pane_session: None,
         };
         let buf = draw(&sb, 44, 8);
         let palette = palette::active();
@@ -759,6 +889,7 @@ mod tests {
             sessions: vec![s],
             highlight: None,
             attached: Default::default(),
+            pane_session: None,
         };
         let buf = draw(&sb, 44, 8);
         let palette = palette::active();
@@ -785,6 +916,7 @@ mod tests {
             sessions: vec![s],
             highlight: None,
             attached: Default::default(),
+            pane_session: None,
         };
         let all = rows(&draw(&sb, 28, 8));
         assert_eq!(content(&all[0]), "sessions");
@@ -816,6 +948,7 @@ mod tests {
             sessions: vec![s],
             highlight: None,
             attached: Default::default(),
+            pane_session: None,
         };
         let all = rows(&draw(&sb, 28, 8));
         let idx = all.iter().position(|l| l.contains("claude")).unwrap();
@@ -855,6 +988,7 @@ mod tests {
                 sessions: vec![s],
                 highlight: None,
                 attached: Default::default(),
+                pane_session: None,
             };
             let buf = draw(&sb, 28, 8);
             let found = (0..buf.area.height)
@@ -883,6 +1017,7 @@ mod tests {
                 sessions: vec![s],
                 highlight: Some(SidebarItem::Session(Uuid::from_u128(1))),
                 attached: Default::default(),
+                pane_session: None,
             };
             let buf = draw(&sb, 28, 8);
             let on_selection = |fg: Color| {
@@ -922,6 +1057,7 @@ mod tests {
             sessions: vec![s],
             highlight: None,
             attached: Default::default(),
+            pane_session: None,
         };
         let all = rows(&draw(&sb, 28, 8));
         let idx = all.iter().position(|l| l.contains("claude")).unwrap();
@@ -941,6 +1077,7 @@ mod tests {
             sessions: vec![s],
             highlight: None,
             attached: Default::default(),
+            pane_session: None,
         };
         let all = rows(&draw(&sb, 60, 6));
         let meta = content(&all[3]);
@@ -969,6 +1106,7 @@ mod tests {
             sessions: vec![s],
             highlight: None,
             attached: Default::default(),
+            pane_session: None,
         };
         let all = rows(&draw(&sb, 28, 8));
         let idx = all.iter().position(|l| l.contains("claude")).unwrap();
@@ -998,6 +1136,7 @@ mod tests {
             sessions: vec![s],
             highlight: None,
             attached: Default::default(),
+            pane_session: None,
         };
         let all = rows(&draw(&sb, 40, 8));
         let idx = all.iter().position(|l| l.contains("claude")).unwrap();
@@ -1025,6 +1164,7 @@ mod tests {
             sessions: vec![s],
             highlight: None,
             attached: Default::default(),
+            pane_session: None,
         };
         let all = rows(&draw(&sb, 40, 8));
         let idx = all.iter().position(|l| l.contains("claude")).unwrap();
@@ -1053,6 +1193,7 @@ mod tests {
             sessions: vec![s],
             highlight: None,
             attached: Default::default(),
+            pane_session: None,
         };
         let all = rows(&draw(&sb, 42, 8));
         let idx = all.iter().position(|l| l.contains("claude")).unwrap();
@@ -1086,6 +1227,7 @@ mod tests {
             sessions: vec![legacy],
             highlight: None,
             attached: Default::default(),
+            pane_session: None,
         };
         let rendered = render_to_string(&draw(&sb, 40, 8));
         assert!(
@@ -1123,11 +1265,13 @@ mod tests {
             activity_since: Utc::now(),
             current_cwd: None,
             blocked_work: None,
+            last_focused_at: None,
         };
         let sb = Sidebar {
             sessions: vec![s],
             highlight: None,
             attached: Default::default(),
+            pane_session: None,
         };
         let rendered = render_to_string(&draw(&sb, 28, 6));
         assert!(
@@ -1143,6 +1287,7 @@ mod tests {
             sessions: vec![s],
             highlight: None,
             attached: Default::default(),
+            pane_session: None,
         };
         let all = rows(&draw(&sb, 40, 6));
         assert!(
@@ -1164,6 +1309,7 @@ mod tests {
             sessions: vec![s],
             highlight: None,
             attached: Default::default(),
+            pane_session: None,
         };
         let all = rows(&draw(&sb, 9, 6));
         assert!(
@@ -1190,6 +1336,7 @@ mod tests {
             sessions: vec![s],
             highlight: None,
             attached: Default::default(),
+            pane_session: None,
         };
         let all = rows(&draw(&sb, 29, 6));
         assert!(all[3].contains("~1"), "{:?}", all[3]);
@@ -1214,6 +1361,7 @@ mod tests {
             sessions: vec![s],
             highlight: None,
             attached: Default::default(),
+            pane_session: None,
         };
         let all = rows(&draw(&sb, 40, 6));
         assert!(all[3].contains("~1"), "{:?}", all[3]);
@@ -1235,6 +1383,7 @@ mod tests {
             sessions: vec![highlighted],
             highlight: Some(SidebarItem::Session(Uuid::from_u128(1))),
             attached: Default::default(),
+            pane_session: None,
         };
         let buf = draw(&sb, 28, 8);
         for y in 0..buf.area.height {
@@ -1260,6 +1409,7 @@ mod tests {
             sessions: vec![one, two],
             highlight: Some(SidebarItem::Session(Uuid::from_u128(1))),
             attached: Default::default(),
+            pane_session: None,
         };
         let buf = draw(&sb, 28, 8);
         let all = rows(&buf);
@@ -1295,6 +1445,7 @@ mod tests {
             sessions: vec![session_named(1, "claude")],
             highlight: Some(SidebarItem::Session(Uuid::from_u128(1))),
             attached: Default::default(),
+            pane_session: None,
         };
         let buf = draw_with_focus(&sb, 28, 8, false);
         let y = (0..buf.area.height)
@@ -1314,6 +1465,7 @@ mod tests {
                 sessions: vec![session_named(1, "claude")],
                 highlight: None,
                 attached: Default::default(),
+                pane_session: None,
             },
             28,
             8,
@@ -1334,6 +1486,7 @@ mod tests {
             sessions: vec![s],
             highlight: None,
             attached: Default::default(),
+            pane_session: None,
         };
         let buf = draw(&sb, 28, 8);
         let y = buf.content.iter().position(|c| c.symbol() == "c").unwrap() as u16 / buf.area.width;
@@ -1352,6 +1505,7 @@ mod tests {
             sessions: vec![session_named(1, "claude")],
             highlight: Some(SidebarItem::Session(Uuid::from_u128(1))),
             attached: Default::default(),
+            pane_session: None,
         };
         let all = rows(&draw(&sb, 28, 8));
         let line = content(row_containing(&all, "claude"));
@@ -1369,6 +1523,7 @@ mod tests {
             sessions: vec![one, two],
             highlight: Some(SidebarItem::Session(Uuid::from_u128(1))),
             attached: Default::default(),
+            pane_session: None,
         };
         let all = rows(&draw(&sb, 28, 8));
         let line = row_containing(&all, "bash");
@@ -1388,6 +1543,7 @@ mod tests {
             sessions: vec![s],
             highlight: Some(SidebarItem::Session(Uuid::from_u128(1))),
             attached: Default::default(),
+            pane_session: None,
         };
         let all = rows(&draw(&sb, 28, 8));
         let line = row_containing(&all, "an-unreasonably");

crates/maestro-tui/src/state.rs

@@ -52,6 +52,10 @@ pub enum OverlayKind {
     /// so this stays comparable.
     Rename(Uuid),
     Help,
+    /// The `ctrl-k` command bar (#153). Its query buffer and result list live
+    /// on `App` as [`crate::command_bar::CommandBar`], for the same reason the
+    /// rename buffer does — so this stays comparable.
+    CommandBar,
     Toast(String),
 }
 

docs/COMMAND-BAR.md

@@ -0,0 +1,479 @@
+# COMMAND-BAR.md — the command bar contract
+
+One rule for the `ctrl-k` command bar in both clients, so the web bar and the
+TUI bar open the same way, rank the same results in the same order, and act on
+the same keys. Read this before changing either. Both clients implement exactly
+what is written here; if the behaviour needs to change, change it here first.
+
+The bar is one surface with three jobs: **go to a session**, **run a command**,
+**spawn into a directory**. It is not a new place to configure anything and it
+does not own any action — it chooses one and hands off to the flow that already
+implements it.
+
+## Opening
+
+`ctrl-k` opens the bar from anywhere:
+
+| Client | From | Notes |
+| --- | --- | --- |
+| TUI | Normal mode | Sidebar has the keyboard. |
+| TUI | Insert mode | The pane has the keyboard; the bar still opens. |
+| Web | Sidebar focused | Ordinary global binding. |
+| Web | Terminal focused | Intercepted before xterm sees it. |
+
+It is a **keymap entry like any other**, not a hard-wired key. In the TUI it is
+bound in both `DEFAULT_NORMAL` and `DEFAULT_INSERT` and is rebindable through
+`[tui.keymap.*]`; because the help overlay builds its lines from the live
+keymap, it appears there without a second list to maintain. In the web it is an
+entry in the command registry, so the `?` overlay lists it for the same reason.
+
+An attached xterm swallows every keystroke it is given, so the web binding is
+handled in the **capture phase**, ahead of the terminal — the same way the
+restart overlay swallows the app's shortcuts (`docs/RESTART.md`).
+
+### Escape hatch — sending a literal Ctrl-K
+
+Binding `ctrl-k` takes readline's kill-to-end-of-line away from every pane. The
+leader gives it back: **leader then `ctrl-k`** — `ctrl-a ctrl-k` by default —
+sends the literal `0x0B` byte to the focused pane and does not open the bar.
+
+The TUI already has a leader (`ctrl-a`, `[tui].leader`), and this chord goes
+through the existing chord resolution, so rebinding the leader rebinds the
+escape hatch with it — exactly as the leader's Insert-mode escape already
+works. **The web gains a leader for this**, defaulting to `ctrl-a` and
+mirroring the TUI's. `ctrl-a` is select-all in a browser; the web
+`preventDefault`s it, since selecting all of a terminal pane does nothing
+useful.
+
+Only Ctrl-K gets an escape hatch. No other control character is intercepted, so
+none of them needs one.
+
+### Focus round-trip
+
+Closing the bar returns the keyboard to whatever held it when the bar opened,
+the terminal included. A round trip through the bar never silently moves focus,
+and never counts as a focus change for the daemon: opening the bar does not
+report the pane unfocused, and closing it does not report a new focus. The bar
+is a view over the app, not a place in it.
+
+Opening the bar while a session is previewed (`docs/PREVIEW.md`) discards the
+preview first, like any other real change; the bar is not previewed into.
+
+## Structure
+
+The bar is a query line over a result list. By default the list is **flat and
+mixed** — sessions and commands ranked together — and rendered under **kind
+headers**: a header row naming the kind, then that kind's results.
+
+Grouping is a rendering of the ranking, never a reordering of it:
+
+- Results are ranked as one list by the algorithm below.
+- A kind's group holds its matches in that rank order.
+- **Groups are ordered by their best-scoring member.** The first row under the
+  first header is therefore the globally best result, and the highlight starts
+  on it.
+
+Two sigils, typed as the **first character** of the query, narrow the list to
+one kind:
+
+| Sigil | Kind | Candidates | Enter |
+| --- | --- | --- | --- |
+| `>` | commands | Every entry in the client's command registry — the web registry from the `?` overlay, the TUI's live `(chord, Action)` keymap for the current mode. | Runs the command. |
+| `~` | directories | Recent dirs (`GET /api/recent-dirs`) and the project list the spawn form already uses, with `GET /api/dirs` filling in as a path is typed. | Spawns a session there with every default resolved. |
+
+While a sigil is in force there is one kind, so the kind header is dropped. A
+command row shows its **key chord** beside its label, so the bar teaches the
+keymap instead of replacing it. A `~` spawn takes the same fast-forward path as
+`N` / `FastForwardSpawn`: an unresolvable default opens the pre-filled spawn
+form rather than failing silently.
+
+**Backspacing past a sigil returns to the mixed list.** The sigil is one
+character of the query like any other — deleting it is not a special key, it is
+the query becoming empty again.
+
+The sigil is only a sigil in first position. `>` or `~` typed anywhere else is
+a literal query character (a directory query is where a `~` is most likely to
+be typed twice, and the second one must reach the matcher).
+
+## Empty query
+
+With no sigil and an empty query the bar lists **sessions only, most recently
+focused first**, so `ctrl-k enter` is "back to where I just was". Commands and
+directories need a sigil or a query to appear; an empty bar is a session
+switcher.
+
+**Recency comes from the daemon**, not from client state — the same order in
+every client, on every device, including one that just loaded the page. The
+daemon stamps a last-focused time per session and ships it on the session like
+any other field (#145). Both of the ways focus moves stamp the same field: a
+client opening `/api/attach/:id`, and a client reporting focus explicitly at
+`POST /api/sessions/:id/focus` when it refocuses a pane that is already open.
+
+**A session that has never been focused sorts after every session that has**,
+and among those, most recently created first. Dead sessions sort after live
+ones regardless of recency: a session you cannot attach to is not where you
+just were.
+
+Under `>` an empty query lists every command in registry order. Under `~` it
+lists recent dirs, most recent first, then the project list.
+
+## Keys
+
+| Key | Action |
+| --- | --- |
+| `enter` | Open the highlighted result — attach the session, run the command, spawn into the directory. |
+| `tab` | Drill into the highlighted **session**'s action page. No effect on any other kind. |
+| `esc` | At the top level, close the bar. On an action page, return to the result list. |
+| `backspace` | Ordinary editing; at an empty query on an action page, return to the result list. |
+| `up` / `down` | Move the highlight. |
+| `ctrl-p` / `ctrl-n` | Move the highlight. |
+
+The highlight does not wrap: it stops at the first and last row. Kind headers
+are never landed on — they are labels, not rows.
+
+Enter on a session goes through the **same open path** the sidebar's click and
+the hash router already share, so a bar attach can never leave the layout in a
+state a click could not produce.
+
+### Drill-in — the session action page
+
+`tab` on a highlighted session opens that session's action page inside the same
+overlay: **kill**, **rename**, **spawn similar**. The page is still fuzzy
+searchable — the query line keeps working, now over those actions.
+
+- The overlay names the session being acted on, so the target is never
+  ambiguous.
+- Escape, or backspace at an empty query, returns to the result list **with the
+  previous query intact**. Drilling in and backing out is free.
+- Each action raises the flow it already has: kill goes through the existing
+  confirm-and-blockers dialog (`docs/WORKTREES.md`), rename through the
+  existing prompt pre-filled with the session's own name
+  (`docs/SIDEBAR.md`), spawn similar through the spawn form seeded from the
+  session's directory and command. The bar picks the action; it never
+  reimplements one.
+
+No actions beyond those three, and no action across more than one session.
+
+## Touch entry
+
+On the web, **tapping or focusing the sidebar's search field opens the bar**
+with an empty query. There is no `ctrl-k` on a phone and the product is
+mobile-first, so the field the operator already reaches for is the entry point.
+
+This **replaces** the sidebar's inline substring filter — one search affordance
+in the header, not two beside each other. The tree's "No matches" empty state
+belonged to that filter and goes with it; the bar's own no-results state takes
+over (see the fixture `F4`).
+
+At phone width the bar follows the bottom-sheet treatment the spawn modal
+already uses below 600px. Visuals otherwise come from `DESIGN.md`'s existing
+overlay tokens — the bar is the same family of surface as the spawn modal and
+the help overlay, not a new one.
+
+## What a candidate is
+
+The matcher is a pure function: `(query, candidates) → ranked subset with
+matched ranges`. It knows nothing about sessions, panes or the network. A
+candidate is a **kind** plus a set of **named text fields**, each with a fixed
+weight.
+
+| Kind | Field | Weight | Text |
+| --- | --- | --- | --- |
+| session | `name` | `0` | The name as the sidebar shows it: `metadata.name` if set, else the command line (`docs/SIDEBAR.md`'s fallback). |
+| session | `directory` | `-24` | The directory the sidebar groups it under, abbreviated: `~/dev/api`, not `/home/me/dev/api`. |
+| session | `command` | `-32` | The full command line, arguments included. |
+| session | `tool` | `-40` | The tool id the card's icon stands for (`claude`, `codex`, `opencode`, …), absent when the program is not one we have a mark for. |
+| command | `label` | `0` | The plain-language label — the web registry's label, the TUI's `Action::help_label`. |
+| directory | `path` | `0` | The path as displayed, abbreviated the same way. |
+
+A command's **key chord is displayed, not matched**. It is there to teach the
+keymap; matching it would make `>` results depend on a user's rebinds, and the
+two clients do not share a keymap.
+
+A candidate **matches** if at least one of its fields matches. Its score is the
+**best** `field score + field weight` across its fields, and the matched ranges
+it returns are those of that winning field — so a session found through its
+directory highlights inside the directory, not inside its name.
+
+## Match and rank
+
+Two independent implementations (#146 in TypeScript, #147 in Rust) must produce
+the same order for the same input. Everything below is exact.
+
+### Normalization
+
+- **Query**: lowercase, then remove every whitespace character. The result is
+  the *normalized query*. If it is empty, see "Empty query" below.
+- **Field text**: matched against its lowercased form. Bonuses are computed
+  against the **original** text, because case is a signal (`camelCase`) that
+  lowercasing destroys.
+- **Compact form** of a string: lowercase with whitespace removed. Used only
+  for the exact and prefix tests.
+
+Lowercasing is per-character simple lowercase (`char::to_lowercase` /
+`String.prototype.toLowerCase`). Positions are **character** positions —
+Unicode scalar values in Rust, UTF-16 code units in TypeScript, which agree for
+every character these fields realistically hold; ranges are returned in the
+host language's own unit, since they exist to slice that language's string.
+
+### What a match is
+
+Case-insensitive **subsequence**: every character of the normalized query
+appears in the lowercased field text, in order, not necessarily adjacent. A
+field with no such embedding does not match.
+
+### Word boundaries
+
+A matched character at position `p` earns exactly one character bonus, taking
+the first rule that applies:
+
+| Rule | Bonus |
+| --- | --- |
+| `p == 0` — first character of the field | `+18` |
+| The character before it is a **separator**: `/` `\` `-` `_` `.` `:` or a space | `+16` |
+| It is uppercase and the character before it is lowercase (a camelCase hump) | `+12` |
+| It is a digit and the character before it is not | `+12` |
+| Otherwise | `0` |
+
+That is one rule for both shapes the doc has to cover. In a **path**, `/` is a
+separator, so the first character of every segment is a word start: `foo` in
+`~/dev/foobar` starts a segment and outscores `foo` in `~/src/myfoo`, which
+starts nothing. In a **session name**, `-`, `_`, `.` and spaces do the same
+work, so `ws` reaches `web-search` more cheaply than `websearch`.
+
+### Score
+
+Let the query characters be matched at positions `p₀ < p₁ < … < pₘ₋₁`, and let
+`p₋₁ = -1`. For each matched character `i`, with `gap = pᵢ - pᵢ₋₁ - 1`:
+
+```
+contribution(i) = 16                      // every matched character
+                + bonus(pᵢ)               // the table above
+                + (gap == 0 ? +8          // adjacent to the previous match
+                            : -min(gap, 12))
+```
+
+`gap` for `i = 0` is the number of characters skipped before the first match, so
+a match that starts late is penalised exactly like an internal gap, and the cap
+is the same one.
+
+The **field score** is the sum of the contributions, plus at most one whole-field
+adjustment:
+
+- compact field text **equals** the normalized query → `+64`
+- else compact field text **starts with** the normalized query → `+32`
+
+Length is deliberately not in the score — it is a tie-break, so a long field
+never loses to a short one that matched worse.
+
+### Which embedding
+
+A query can sit in a field many ways. The one that counts is the
+**highest-scoring** embedding; among embeddings that score the same, the
+**leftmost** — compare position vectors element by element, smaller wins.
+
+Greedy leftmost-first matching is not sufficient and must not be used: in
+`maestro-tui`, `mtu` greedily takes `m₀ a₁ …` and never reaches `tui`. Both
+implementations use the obvious dynamic program over
+`(query index, text position)`, carrying the best score and its position
+vector, since the gap term depends only on the previous matched position.
+
+The whole-field adjustment is constant for a `(query, field)` pair, so adding it
+after the dynamic program cannot change which embedding wins.
+
+### Ordering
+
+Sort by score, highest first. Equal scores break in this order:
+
+1. **Kind** — `session`, then `command`, then `directory`.
+2. **Length of the matched field text**, shorter first.
+3. **The matched field text**, ascending, compared by code point, case
+   sensitive.
+4. **Input order.** The sort is stable, so candidates the caller ordered
+   deliberately — sessions most recently focused first, commands in registry
+   order — keep that order when nothing else separates them.
+
+Kind leads because that is the ruling the ambiguous cases need: a session named
+`kill` and the `kill` command that score alike put the session first, because
+the operator who typed a session's name meant the session.
+
+### Empty query
+
+A normalized query that is empty **matches every candidate**, each with score
+`0` and no ranges, in input order. The bar's own rules decide what is in the
+candidate list at that point (sessions only at the top level); the matcher does
+not filter by kind.
+
+## Fixtures
+
+These are the contract. Both matchers are tested against exactly these cases;
+the prose above is the explanation of why they come out this way.
+
+Candidates are written as `kind(fields)`; unlisted fields are absent.
+`session(name, dir, command, tool)`. Scores are shown for diagnosis — **the
+order is what is being asserted**, and an implementation that ranks correctly
+with different absolute numbers has still failed, because the numbers are how
+the next fixture stays predictable.
+
+### F1 — empty query keeps input order
+
+```
+query:      ""
+candidates: session("kill", "~/dev/api", "bash")
+            session("killer-app", "~/dev/killer-app", "claude --resume", "claude")
+            command("Kill selected session")
+expected:   session("kill")           score 0
+            session("killer-app")     score 0
+            command("Kill selected session")  score 0
+```
+
+Every candidate matches, in the order given. No ranges.
+
+### F2 — a session named `kill` against the `kill` command
+
+```
+query:      "kill"
+candidates: (as F1)
+expected:   session("kill")                   178   name
+            session("killer-app")             146   name
+            command("Kill selected session")  146   label
+```
+
+`kill` wins on the exact bonus. The other two **tie at 146** — both are a
+contiguous prefix match — and the kind tie-break puts the session first.
+
+### F3 — a fragment matching mid-segment inside a path
+
+```
+query:      "foo"
+candidates: directory("~/dev/foobar")
+            directory("~/src/myfoo")
+            directory("~/foo")
+expected:   directory("~/foo")         78   ranges [2,3,4]
+            directory("~/dev/foobar")  74   ranges [6,7,8]
+            directory("~/src/myfoo")   56   ranges [8,9,10]
+```
+
+The first two start a path segment; the third is mid-segment and loses by the
+whole boundary bonus. `~/foo` beats `~/dev/foobar` only because less was
+skipped before the match.
+
+### F4 — a query matching nothing
+
+```
+query:      "zzz"
+candidates: session("kill", "~/dev/api", "bash")
+            command("Kill selected session")
+expected:   (empty)
+```
+
+The matcher returns an empty list, never a list of zero-scored candidates. The
+bar renders its no-results state.
+
+### F5 — a non-contiguous subsequence
+
+```
+query:      "mtu"
+candidates: session("maestro-tui")
+            session("maestro-daemon")
+            session("mtui-scratch")
+expected:   session("mtui-scratch")  122   ranges [0,1,2]
+            session("maestro-tui")    91   ranges [0,8,9]
+```
+
+`maestro-daemon` has no `u` after its `t` and does not match. `maestro-tui`
+does, across a gap — which greedy matching would miss entirely.
+
+### F6 — a name beats a directory
+
+```
+query:      "api"
+candidates: session("api", "~/dev/web", "bash")
+            session("worker", "~/dev/api", "bash")
+expected:   session("api")     154   name
+            session("worker")   50   directory
+```
+
+The second session is found through its directory, and highlights there.
+
+### F7 — case-insensitive, tie broken by length
+
+```
+query:      "api"
+candidates: session("API-Gateway")
+            session("apiary")
+expected:   session("apiary")       122   name
+            session("API-Gateway")  122   name
+```
+
+Both are prefix matches and score identically. Same kind, so length decides:
+6 characters before 11. Input order does not save `API-Gateway`.
+
+### F8 — the tool field
+
+```
+query:      "claude"
+candidates: session("nameless", "~/dev/x", "claude --resume", "claude")
+            session("clay", "~/dev/y", "bash")
+expected:   session("nameless")  186   tool
+```
+
+`clay` has no `claude` subsequence anywhere and drops out. `nameless` matches
+its `tool` exactly (`+64`, weight `-40`, giving 186) which beats the prefix
+match on its `command` field (`+32`, weight `-32`, giving 162).
+
+### F9 — a word boundary inside a session name
+
+```
+query:      "ws"
+candidates: session("websearch")
+            session("web-search")
+expected:   session("web-search")  71   ranges [0,4]
+            session("websearch")   56   ranges [0,3]
+```
+
+The `s` after `-` earns the boundary bonus; the `s` inside `websearch` earns
+nothing.
+
+### F10 — command labels
+
+```
+query:      "se"
+candidates: command("Kill selected session")
+            command("Create a session")
+            command("Show help")
+expected:   command("Show help")             53   ranges [0,6]
+            command("Kill selected session") 51   ranges [5,6]
+            command("Create a session")      47   ranges [9,10]
+```
+
+`Show help` starts at position 0; the other two start at a word boundary but
+later, and pay for the skipped characters.
+
+### F11 — a query against session directories
+
+```
+query:      "dev"
+candidates: session("api", "~/dev/api", "bash")
+            session("notes", "~/documents/dev-notes", "nvim")
+            session("scratch", "~/srv/devops", "bash")
+expected:   session("api")      54   directory, ranges [2,3,4]
+            session("scratch")  50   directory, ranges [6,7,8]
+            session("notes")    44   directory, ranges [12,13,14]
+```
+
+All three start a path segment. They separate purely on how much was skipped
+first, and `notes` hits the `-12` gap cap.
+
+### F12 — exact beats prefix
+
+```
+query:      "quit"
+candidates: command("Quit Maestro")
+            command("Quit")
+expected:   command("Quit")           178   label
+            command("Quit Maestro")   146   label
+```
+
+The 32-point difference between the exact and prefix adjustments is the whole
+gap; nothing else about the two matches differs.

docs/PREVIEW.md

@@ -32,6 +32,33 @@ The throwaway tab never counts as an open session: the tab bar does not appear
 because of it, the mobile shell does not switch away from the session list for
 it, and the sidebar does not mark the session as open.
 
+## How a preview reads
+
+A preview is provisional, so it never wears the accent — the accent is what
+says "this is the one you picked". It has a hue of its own, and every surface
+involved in the preview carries that same hue, so the pane and the row it came
+from read as one thing rather than two unrelated highlights.
+
+Web client (`--preview` and friends in `web/src/styles.css`):
+
+| Surface | While previewing |
+|---|---|
+| The previewed pane's titlebar | Tinted in the preview hue, at full strength, in place of the focused pane's accent tint. |
+| The canvas | A `preview` chip, top right, and a dashed inset ring. |
+| A throwaway tab | Dashed border, italic label. |
+| The sidebar row being previewed | Filled with the preview hue, over whatever open/focused state the row already had. |
+| A hovered sidebar row, and the keyboard cursor on a session | A lighter wash of the same hue, because both are what previews a row. |
+
+Rows say it with fill, not with an edge — see the tier ladder in
+`docs/SIDEBAR.md`, which previewing sits at the bottom of. The dashed edges
+belong to the pane: the canvas ring and the throwaway tab.
+
+The hue is a palette token, not a fixed colour: a palette whose accent already
+sits on it moves it (`--preview-h`), so "previewing" and "picked" never collide.
+
+The TUI marks a preview in text only — the title bar reads `<name>  ·  preview`
+— and has no preview colour role yet.
+
 ## What ends a preview
 
 - The highlight moves to another session — that session is previewed instead.
@@ -50,15 +77,19 @@ Nothing moves a second time on commit.
 
 ## Timing
 
-A preview follows the highlight closely enough to be usable as a way to look
-around, and lags a pointer enough not to flash rows crossed on the way
-somewhere else.
+**A preview is never delayed.** Landing on a row — by pointer or by `j`/`k` —
+shows it on the next frame, and so does leaving every row. There is no
+settling period in front of the first preview, because that period would sit
+in front of the one preview the operator actually meant.
 
-| Trigger | Delay |
-|---|---|
-| Keyboard step (`j`/`k`, arrows) | 60 ms |
-| Pointer hover (web, mouse only — never touch) | 150 ms |
-| Clearing (highlight left every session) | same delay as the trigger that set it |
+What is bounded is how *often* the pane may swap: at most once per 120 ms.
+A burst inside one window — `j` held down, or the pointer sweeping the length
+of the sidebar — shows the row it started on, then the row it ended on, and
+none of the rows in between. So a walk costs a couple of pane mounts rather
+than one per row, without the operator ever waiting on one.
+
+The highlight itself is not bounded by any of this: the row lights up on the
+same frame as the input, whatever the pane behind it is doing.
 
 Touch has no hover, and a tap already opens a session, so touch never previews.
 

docs/SIDEBAR.md

@@ -177,6 +177,38 @@ surface; a colour chosen for the card background is never painted onto the
 selection background. Contrast is a property of the palette (values are RGB)
 and is asserted in the palette's tests, not left to the terminal theme.
 
+## Which row is filled
+
+Both clients say every one of these with a **background fill**, never an edge.
+A row is usually several of them at once, so they form a ladder: the tier
+furthest down wins the paint.
+
+| Tier | Web | TUI |
+|---|---|---|
+| Alive | 6% accent wash | — (the rail carries it) |
+| Under the pointer or the keyboard walk | preview hue, light | selection surface, while the sidebar holds the keyboard |
+| Open in some pane, not the focused one | 6% accent wash (`.is-open`) | — (the `●` glyph carries it) |
+| Showing in the pane | `--accent-fill` | `pane_row_bg()` — partway from the card surface to the selection surface |
+| Previewing (`docs/PREVIEW.md`) | `--preview-tint` | — (no preview colour role yet) |
+
+The web ladder is written as one ordered run of equal-specificity rules in
+`styles.css`, every qualifier inside `:where()`, so the order they appear in
+*is* the precedence. Add a tier where it belongs in that run, never by piling
+on another class to out-weigh the rule above it.
+
+The TUI's two filled tiers both carry the **selection** surface's foregrounds,
+since those are the colours picked for a filled row. `pane_row_bg()` is
+blended from the two surfaces rather than shipped as a third one — a third
+surface would mean eight more colours hand-picked seventeen times — and the
+palette tests assert it stays a visible step from both. The cursor's fill wins
+on its own row, so a highlight parked on the session already in the pane is
+still visible.
+
+The one edge left in either list is the TUI's `▏` marker, which stands in for
+the cursor's fill while the pane holds the keyboard, and the web's ring on a
+highlighted **folder** row — a folder previews nothing, so it has no fill to
+step up to.
+
 The duration text inherits its state's colour; the exited and command
 fragments use the surface's `muted` role, as do the diff stat's `~`, `?` and
 `↑` fragments. Only `+` and `-` step outside the surface's muted role, and they

web/src/attach.ts

@@ -5,6 +5,7 @@ import "@xterm/xterm/css/xterm.css";
 
 import { attachWsUrl } from "./routes.js";
 import { FOCUS_SIDEBAR_EVENT } from "./catalog.js";
+import { CommandSet, defineCommands } from "./commands.js";
 import { escapeHtml } from "./html.js";
 import { INITIAL_RECONNECT_MS, MAX_RECONNECT_MS } from "./reconnect.js";
 import { applyModsToChar, cursorSeq, tildeSeq } from "./keys.js";
@@ -13,6 +14,15 @@ import { splitCommand, toolIconSvg } from "./toolIcon.js";
 import type { ClientControl, Uuid } from "./types.js";
 import { WebglPolicy } from "./webglRenderer.js";
 
+// The pane's half of the command registry (#148): plain Escape hands the
+// keyboard back to the session list, the pair to the list's Tab.
+const paneKeys = new CommandSet(
+  defineCommands({
+    "pane.focusList": () => document.dispatchEvent(new CustomEvent(FOCUS_SIDEBAR_EVENT)),
+  }),
+  { preventDefault: false },
+);
+
 /** One budget for the whole page — see webglRenderer.ts for why contexts are
  *  rationed rather than handed to every connection. */
 const webglPolicy = new WebglPolicy();
@@ -40,6 +50,10 @@ export interface AttachConnection {
   onUnmount(): void;
   /** Put the keyboard back into this terminal — what leaving the sidebar does. */
   focusTerminal(): void;
+  /** Type raw bytes straight into the PTY, bypassing the terminal's own key
+   *  handling — the leader's literal Ctrl-K escape hatch
+   *  (docs/COMMAND-BAR.md). */
+  sendInput(data: string): void;
   /** Fully disconnect: close the WS, dispose the terminal, remove the element. */
   dispose(): void;
 }
@@ -56,8 +70,6 @@ export interface AttachOptions {
   shouldReconnect?: (sessionId: Uuid, code: number) => boolean;
 }
 
-
-
 /** What the header shows about the session (name / command). Optional — falls
  * back to a short session id when the session isn't known yet. */
 export interface AttachInfo {
@@ -210,12 +222,12 @@ export function createAttachConnection(
   }
 
   // Plain Escape hands the keyboard back to the session list instead of the
-  // shell/app. `false` tells xterm to skip its own handling of this event.
+  // shell/app. `false` tells xterm to skip its own handling of this event —
+  // which is also why the set doesn't `preventDefault`: swallowing here is
+  // xterm's return value, not the browser's.
   term.attachCustomKeyEventHandler((e) => {
-    if (e.type !== "keydown" || e.key !== "Escape") return true;
-    if (e.ctrlKey || e.altKey || e.metaKey || e.shiftKey) return true;
-    document.dispatchEvent(new CustomEvent(FOCUS_SIDEBAR_EVENT));
-    return false;
+    if (e.type !== "keydown") return true;
+    return !paneKeys.handle(e);
   });
 
   // Touch scrolling: xterm's built-in touch handling is jittery (drags crawl a
@@ -498,6 +510,9 @@ export function createAttachConnection(
     focusTerminal() {
       term.focus();
     },
+    // The closure above: the same bytes-out path keystrokes and the mobile key
+    // bar already take.
+    sendInput,
     dispose() {
       if (disposed) return;
       disposed = true;

web/src/catalog.ts

@@ -2,7 +2,8 @@ import { escapeHtml } from "./html.js";
 import { ApiRequestError, getDaemonInfo, killSession, renameSession } from "./api.js";
 import { openForceKillDialog } from "./killDialog.js";
 import { openContextMenu } from "./contextMenu.js";
-import { isTypingTarget, toggleHelp } from "./help.js";
+import { toggleHelp } from "./help.js";
+import { CommandSet, defineCommands } from "./commands.js";
 import { CatalogStore } from "./events.js";
 import type { InTheWay, Session } from "./types.js";
 import {
@@ -164,6 +165,10 @@ function renderNode(node: TreeNode, depth: number): HTMLElement {
     return wrap;
   }
 
+  // The row outlives the snapshot it was built from: a refresh that changes
+  // nothing structural patches it in place rather than replacing it, so the
+  // handlers below have to read the current session, not the one captured here.
+  let cur = node.session;
   const s = node.session;
   const now = Date.now();
   const row = document.createElement("a");
@@ -197,33 +202,74 @@ function renderNode(node: TreeNode, depth: number): HTMLElement {
   similarBtn.addEventListener("click", (ev) => {
     ev.preventDefault();
     ev.stopPropagation();
-    document.dispatchEvent(new CustomEvent(SPAWN_SIMILAR_EVENT, { detail: s }));
+    document.dispatchEvent(new CustomEvent(SPAWN_SIMILAR_EVENT, { detail: cur }));
   });
   const killBtn = row.querySelector(".leaf-kill") as HTMLButtonElement;
   killBtn.addEventListener("click", (ev) => {
     ev.preventDefault();
     ev.stopPropagation();
-    void requestKill(s, name);
+    void requestKill(cur, sessionName(cur));
   });
   row.addEventListener("click", () => {
-    document.dispatchEvent(new CustomEvent(SESSION_SELECT_EVENT, { detail: s.id }));
+    document.dispatchEvent(new CustomEvent(SESSION_SELECT_EVENT, { detail: cur.id }));
   });
   row.addEventListener("contextmenu", (ev) => {
     ev.preventDefault();
     ev.stopPropagation();
     openContextMenu(ev.clientX, ev.clientY, [
-      { label: "Rename…", onSelect: () => beginRename(row, s) },
+      { label: "Rename…", onSelect: () => beginRename(row, cur) },
       {
         label: "Spawn similar",
         onSelect: () =>
-          document.dispatchEvent(new CustomEvent(SPAWN_SIMILAR_EVENT, { detail: s })),
+          document.dispatchEvent(new CustomEvent(SPAWN_SIMILAR_EVENT, { detail: cur })),
+      },
+      {
+        label: "Kill session",
+        danger: true,
+        onSelect: () => void requestKill(cur, sessionName(cur)),
       },
-      { label: "Kill session", danger: true, onSelect: () => void requestKill(s, name) },
     ]);
   });
+  leafPatches.set(row, (next) => {
+    cur = next;
+    const nextSlug = activityColorSlug(next.activity ?? "Idle");
+    const nextWord = STATE_WORDS[nextSlug] ?? STATE_WORDS.idle;
+    row.setAttribute(
+      "aria-label",
+      `${sessionName(next)}, ${next.status === "Running" ? "running" : "exited"}, ${nextWord}`,
+    );
+    const rail = row.querySelector(".activity-rail");
+    if (rail) rail.outerHTML = activityRailMarkup(nextSlug, nextWord);
+    const meta = row.querySelector(".card-line2");
+    if (meta) meta.outerHTML = metaLine(next, Date.now());
+  });
   return row;
 }
 
+/** Refresh a standing card from a newer snapshot of its session, keeping the
+ *  element (and so the pointer's `:hover`) exactly where it is. Registered by
+ *  `renderNode`; only the bits `treeSignature` leaves out are rewritten. */
+const leafPatches = new WeakMap<HTMLElement, (s: Session) => void>();
+
+/**
+ * Everything about the tree that a patch cannot fix up.
+ *
+ * The daemon re-sends a session on every activity, foreground or cwd shift —
+ * a couple of times a minute per live session — and rebuilding the sidebar for
+ * each one drops `:hover` from the row under the pointer. Refreshes whose
+ * signature is unchanged are patched into the standing rows instead; anything
+ * that moves, renames, appears or dies changes the signature and rebuilds.
+ */
+function treeSignature(node: TreeNode): string {
+  if (node.kind === "folder") {
+    const head = `F:${node.name}:${node.path}:${collapsed.has(node.path)}`;
+    if (node.name && collapsed.has(node.path)) return head;
+    return `${head}(${node.children.map(treeSignature).join(",")})`;
+  }
+  const s = node.session;
+  return `L:${s.id}:${sessionName(s)}:${s.status}:${isProvisionalName(s)}`;
+}
+
 /**
  * Kill on the first click (#81): the daemon is the one that decides whether a
  * session may go, and it refuses over a worktree holding unsaved work. Only
@@ -342,6 +388,9 @@ export interface SidebarHandle {
   setActive(id: string | null): void;
   /** Apply the full open/focused highlight state. */
   setHighlights(h: SidebarHighlights): void;
+  /** Mark the row the content pane is previewing (docs/PREVIEW.md), or clear it
+   *  with `null`. A preview is a view, not state, so this only paints. */
+  setPreview(sessionId: string | null): void;
   /** Hand the keyboard to the session list, highlighting a row to walk from. */
   focusList(): void;
   /** Whether the session list currently holds DOM focus. */
@@ -368,7 +417,7 @@ export interface SidebarOptions {
    *  shell shows it in the content pane without opening it (docs/PREVIEW.md).
    *  `source` is there so a mouse sweep can be debounced differently from a
    *  keyboard step. */
-  onPreview?: (sessionId: string | null, source: "key" | "hover") => void;
+  onPreview?: (sessionId: string | null) => void;
 }
 
 export function renderSidebar(store: CatalogStore, opts: SidebarOptions = {}): SidebarHandle {
@@ -501,6 +550,10 @@ export function renderSidebar(store: CatalogStore, opts: SidebarOptions = {}): S
   });
 
   let highlights: SidebarHighlights = { open: new Set(), focused: null };
+  // The previewed row is painted alongside the open/focused tiers so a
+  // re-render can't drop it, but it is never part of `highlights`: a preview
+  // is a view, and nothing about it is durable (docs/PREVIEW.md).
+  let previewing: string | null = null;
   const applyHighlights = () => {
     for (const n of treeHost.querySelectorAll<HTMLElement>(".tree-leaf")) {
       const id = n.dataset.sessionId;
@@ -509,6 +562,7 @@ export function renderSidebar(store: CatalogStore, opts: SidebarOptions = {}): S
       const open = highlights.open.has(id);
       n.classList.toggle("is-active", focused);
       n.classList.toggle("is-open", open && !focused);
+      n.classList.toggle("is-previewing", previewing === id);
     }
   };
 
@@ -547,7 +601,7 @@ export function renderSidebar(store: CatalogStore, opts: SidebarOptions = {}): S
     navKey = next.dataset.navKey ?? null;
     applyNav();
     next.scrollIntoView({ block: "nearest" });
-    opts.onPreview?.(sessionOf(navKey), "key");
+    opts.onPreview?.(sessionOf(navKey));
   };
 
   /** Enter: open the highlighted session, or expand the highlighted folder. */
@@ -578,7 +632,7 @@ export function renderSidebar(store: CatalogStore, opts: SidebarOptions = {}): S
   const setHovered = (id: string | null) => {
     if (hovered === id) return;
     hovered = id;
-    opts.onPreview?.(id, "hover");
+    opts.onPreview?.(id);
   };
   treeHost.addEventListener("pointerover", (e) => {
     if (e.pointerType === "touch") return;
@@ -595,7 +649,7 @@ export function renderSidebar(store: CatalogStore, opts: SidebarOptions = {}): S
   treeHost.tabIndex = -1;
   // The keyboard walk's preview belongs to the list having the keyboard: once
   // it doesn't, the content pane goes back to what the operator actually opened.
-  treeHost.addEventListener("blur", () => opts.onPreview?.(null, "key"));
+  treeHost.addEventListener("blur", () => opts.onPreview?.(null));
 
   /** The session behind the highlighted row, if the highlight is on a card. */
   const highlightedSession = (): { row: HTMLElement; session: Session } | undefined => {
@@ -616,24 +670,33 @@ export function renderSidebar(store: CatalogStore, opts: SidebarOptions = {}): S
     applyNav();
   };
 
-  treeHost.addEventListener("keydown", (e) => {
-    if (e.ctrlKey || e.altKey || e.metaKey) return;
-    // The inline rename field lives inside a row and owns its own keys.
-    if (isTypingTarget(e.target)) return;
-    if (e.key === "j" || e.key === "ArrowDown") moveNav(1);
-    else if (e.key === "k" || e.key === "ArrowUp") moveNav(-1);
-    else if (e.key === "Enter") activateNav();
-    else if (e.key === "Tab") document.dispatchEvent(new CustomEvent(FOCUS_PANE_EVENT));
-    else if (e.key === "c") toggleHighlightedFolder();
-    else if (e.key === "x") {
-      const hit = highlightedSession();
-      if (hit) void requestKill(hit.session, sessionName(hit.session));
-    } else if (e.key === "r") {
-      const hit = highlightedSession();
-      if (hit) beginRename(hit.row, hit.session);
-    } else return;
-    e.preventDefault();
-  });
+  // The session list's half of the command registry (#148). One set per
+  // sidebar, so a second sidebar (tests, hot reload) drives its own rows; the
+  // labels and chords still come from the one registry.
+  const listKeys = new CommandSet(
+    defineCommands({
+      "list.next": () => moveNav(1),
+      "list.prev": () => moveNav(-1),
+      "list.activate": () => activateNav(),
+      "list.toggleFolder": () => toggleHighlightedFolder(),
+      "list.rename": () => {
+        const hit = highlightedSession();
+        if (hit) beginRename(hit.row, hit.session);
+      },
+      "list.kill": () => {
+        const hit = highlightedSession();
+        if (hit) void requestKill(hit.session, sessionName(hit.session));
+      },
+      "list.focusPane": () => document.dispatchEvent(new CustomEvent(FOCUS_PANE_EVENT)),
+    }),
+  );
+
+  // The inline rename field lives inside a row and owns its own keys; the set's
+  // plain-key rule keeps this walk out of it.
+  treeHost.addEventListener("keydown", (e) => listKeys.handle(e));
+
+  /** Signature of what is currently on screen — see `treeSignature`. */
+  let renderedSignature: string | null = null;
 
   const refresh = () => {
     // Rebuilding the tree now would blow away the field being typed into.
@@ -641,6 +704,15 @@ export function renderSidebar(store: CatalogStore, opts: SidebarOptions = {}): S
     const state = store.snapshot();
     const sessions = [...state.sessions.values()];
     const tree = buildTree(sessions, homeDir, filter);
+    const signature = sessions.length === 0 ? `EMPTY:${filter.trim()}` : treeSignature(tree);
+    if (signature === renderedSignature) {
+      for (const row of treeHost.querySelectorAll<HTMLElement>(".tree-leaf")) {
+        const s = row.dataset.sessionId ? state.sessions.get(row.dataset.sessionId) : undefined;
+        if (s) leafPatches.get(row)?.(s);
+      }
+      return;
+    }
+    renderedSignature = signature;
     treeHost.replaceChildren();
     if (sessions.length === 0) {
       treeHost.appendChild(
@@ -664,7 +736,13 @@ export function renderSidebar(store: CatalogStore, opts: SidebarOptions = {}): S
       /* absolute paths are a fine fallback */
     });
 
-  const rerenderHandler = () => refresh();
+  // Dispatched when something outside the store changed what the tree should
+  // look like — a folder collapsed, a rename ended — none of which the store
+  // snapshot can show, so the signature check has to be bypassed.
+  const rerenderHandler = () => {
+    renderedSignature = null;
+    refresh();
+  };
   document.addEventListener("catalog-rerender", rerenderHandler);
 
   // "Spawn similar" (#28) is dispatched here and handled in main.ts, where the
@@ -692,6 +770,10 @@ export function renderSidebar(store: CatalogStore, opts: SidebarOptions = {}): S
       highlights = h;
       applyHighlights();
     },
+    setPreview(sessionId: string | null) {
+      previewing = sessionId;
+      applyHighlights();
+    },
     focusList() {
       // Start from the session on screen — that is where the user's attention
       // already is — falling back to the standing highlight, then the top row.

web/src/catalogPatch.test.ts

@@ -0,0 +1,105 @@
+// @vitest-environment happy-dom
+import { beforeAll, describe, expect, it } from "vitest";
+
+import { renderSidebar } from "./catalog.js";
+import type { CatalogListener, CatalogStore } from "./events.js";
+import type { Session } from "./types.js";
+
+beforeAll(() => {
+  Object.defineProperty(window, "localStorage", {
+    value: { getItem: () => null, setItem: () => {} },
+  });
+  window.fetch = () => Promise.reject(new Error("offline"));
+});
+
+const ID = "11111111-2222-3333-4444-555555555555";
+
+function session(overrides: Partial<Session> = {}): Session {
+  return {
+    id: ID,
+    cwd: "/home/naps/tea/maestro",
+    command: "claude",
+    env: {},
+    metadata: {},
+    status: "Running",
+    created_at: "2026-08-24T10:00:00Z",
+    ...overrides,
+  };
+}
+
+/** A store whose updates actually reach subscribers, unlike the one-shot
+ *  harness in catalog.test.ts. */
+function liveStore(initial: Session[]) {
+  const state = { sessions: new Map(initial.map((s) => [s.id, s])) };
+  const listeners = new Set<CatalogListener>();
+  const store = {
+    snapshot: () => state,
+    subscribe: (fn: CatalogListener) => {
+      listeners.add(fn);
+      fn(state);
+      return () => listeners.delete(fn);
+    },
+  } as unknown as CatalogStore;
+  const push = (sessions: Session[]) => {
+    state.sessions = new Map(sessions.map((s) => [s.id, s]));
+    for (const fn of listeners) fn(state);
+  };
+  return { store, push };
+}
+
+const rowOf = (el: HTMLElement) => el.querySelector<HTMLElement>(".tree-leaf")!;
+
+describe("sidebar refresh keeps rows in place (docs/SIDEBAR.md)", () => {
+  it("patches an activity change into the standing row instead of rebuilding it", () => {
+    const { store, push } = liveStore([session({ activity: "Idle" })]);
+    const { el } = renderSidebar(store, {});
+    const before = rowOf(el);
+
+    push([session({ activity: "AwaitingInput" })]);
+
+    // Same element: a rebuild under the pointer would drop `:hover` and restart
+    // the row's transitions, which is the flicker this avoids.
+    expect(rowOf(el)).toBe(before);
+    // …and the card still tells the truth about the session.
+    expect(before.querySelector(".activity-rail")?.getAttribute("data-activity")).toBe(
+      "awaiting-input",
+    );
+    expect(before.querySelector(".card-line2")?.getAttribute("data-activity")).toBe(
+      "awaiting-input",
+    );
+    expect(before.getAttribute("aria-label")).toContain("Awaiting input");
+  });
+
+  it("rebuilds when the row set changes", () => {
+    const { store, push } = liveStore([session()]);
+    const { el } = renderSidebar(store, {});
+    const before = rowOf(el);
+
+    push([session(), session({ id: "99999999-2222-3333-4444-555555555555", command: "bash" })]);
+
+    expect(el.querySelectorAll(".tree-leaf")).toHaveLength(2);
+    expect(rowOf(el)).not.toBe(before);
+  });
+
+  it("rebuilds when a session dies", () => {
+    const { store, push } = liveStore([session()]);
+    const { el } = renderSidebar(store, {});
+    const before = rowOf(el);
+
+    push([session({ status: "Dead" })]);
+
+    expect(rowOf(el)).not.toBe(before);
+    expect(rowOf(el).dataset.status).toBe("dead");
+  });
+
+  it("rebuilds when a session is renamed", () => {
+    const { store, push } = liveStore([session()]);
+    const { el } = renderSidebar(store, {});
+    const before = rowOf(el);
+
+    push([session({ metadata: { name: "harmony" } })]);
+
+    expect(rowOf(el)).not.toBe(before);
+    expect(rowOf(el).querySelector(".leaf-name")?.textContent).toBe("harmony");
+  });
+});

web/src/commandBar.test.ts

@@ -0,0 +1,544 @@
+// @vitest-environment happy-dom
+import { afterEach, describe, expect, it, vi } from "vitest";
+
+import { SESSION_SELECT_EVENT } from "./catalog.js";
+import {
+  barGroups,
+  barRows,
+  closeCommandBar,
+  commandBarCandidates,
+  dedupeCommands,
+  directoryBarCandidates,
+  directoryCandidate,
+  isCommandBarOpen,
+  openCommandBar,
+  orderSessionsForBar,
+  parseBarQuery,
+  sessionBarCandidates,
+  sessionCandidate,
+  SPAWN_DIRECTORY_EVENT,
+} from "./commandBar.js";
+import { COMMAND_SPECS, type Command } from "./commands.js";
+import type { Session } from "./types.js";
+
+function session(id: string, over: Partial<Session> = {}): Session {
+  return {
+    id,
+    cwd: "/home/me/dev/api",
+    command: "bash",
+    env: {},
+    metadata: { name: id },
+    status: "Running",
+    created_at: "2026-01-01T00:00:00Z",
+    ...over,
+  };
+}
+
+afterEach(() => {
+  closeCommandBar();
+  document.body.replaceChildren();
+});
+
+function press(key: string, init: KeyboardEventInit = {}): void {
+  const input = document.querySelector(".cmdbar-input") as HTMLInputElement;
+  input.dispatchEvent(new KeyboardEvent("keydown", { key, bubbles: true, ...init }));
+}
+
+function type(value: string): void {
+  const input = document.querySelector(".cmdbar-input") as HTMLInputElement;
+  input.value = value;
+  input.dispatchEvent(new Event("input", { bubbles: true }));
+}
+
+function rowNames(): string[] {
+  return [...document.querySelectorAll(".cmdbar-row-name")].map((r) => r.textContent ?? "");
+}
+
+function activeName(): string | undefined {
+  return document.querySelector(".cmdbar-row.is-active .cmdbar-row-name")?.textContent ?? undefined;
+}
+
+describe("empty-query ordering", () => {
+  it("sorts most recently focused first", () => {
+    const older = session("older", { last_focused_at: "2026-01-01T10:00:00Z" });
+    const newer = session("newer", { last_focused_at: "2026-01-01T11:00:00Z" });
+    expect(orderSessionsForBar([older, newer]).map((s) => s.id)).toEqual(["newer", "older"]);
+  });
+
+  it("sorts a never-focused session after every focused one, newest created first", () => {
+    const focused = session("focused", {
+      last_focused_at: "2020-01-01T00:00:00Z",
+      created_at: "2020-01-01T00:00:00Z",
+    });
+    const oldFresh = session("old-fresh", { created_at: "2026-01-01T00:00:00Z" });
+    const newFresh = session("new-fresh", { created_at: "2026-06-01T00:00:00Z" });
+    expect(orderSessionsForBar([oldFresh, newFresh, focused]).map((s) => s.id)).toEqual([
+      "focused",
+      "new-fresh",
+      "old-fresh",
+    ]);
+  });
+
+  it("sorts dead sessions after live ones regardless of recency", () => {
+    const deadRecent = session("dead", {
+      status: "Dead",
+      last_focused_at: "2026-06-01T00:00:00Z",
+    });
+    const liveStale = session("live", { last_focused_at: "2020-01-01T00:00:00Z" });
+    const liveNever = session("never");
+    expect(orderSessionsForBar([deadRecent, liveNever, liveStale]).map((s) => s.id)).toEqual([
+      "live",
+      "never",
+      "dead",
+    ]);
+  });
+
+  it("treats a null last_focused_at as never focused", () => {
+    const nulled = session("nulled", { last_focused_at: null });
+    const stamped = session("stamped", { last_focused_at: "2020-01-01T00:00:00Z" });
+    expect(orderSessionsForBar([nulled, stamped]).map((s) => s.id)).toEqual(["stamped", "nulled"]);
+  });
+});
+
+describe("session candidates", () => {
+  it("carries the candidate table's fields, with the directory abbreviated", () => {
+    const s = session("api", {
+      metadata: { name: "api" },
+      command: "claude --resume",
+      current_cwd: "/home/me/dev/api",
+    });
+    expect(sessionCandidate(s, "/home/me")).toEqual({
+      kind: "session",
+      session: s,
+      fields: {
+        name: "api",
+        directory: "~/dev/api",
+        command: "claude --resume",
+        tool: "claude",
+      },
+    });
+  });
+
+  it("leaves the tool out when the program has no mark, and groups a worktree by its repo", () => {
+    const s = session("edit", {
+      metadata: {},
+      command: "hx src/",
+      worktree: { path: "/home/me/dev/api/wt/x", base_repo: "/home/me/dev/api" },
+    });
+    const candidate = sessionCandidate(s, "/home/me");
+    expect(candidate.fields.tool).toBeUndefined();
+    expect(candidate.fields.directory).toBe("~/dev/api");
+    // No `metadata.name`: the sidebar's fallback is the command line.
+    expect(candidate.fields.name).toBe("hx src/");
+  });
+
+  it("builds candidates in the empty-query order", () => {
+    const a = session("a", { last_focused_at: "2026-01-01T10:00:00Z" });
+    const b = session("b", { last_focused_at: "2026-01-01T11:00:00Z" });
+    expect(sessionBarCandidates([a, b]).map((c) => c.session.id)).toEqual(["b", "a"]);
+  });
+});
+
+describe("rows and grouping", () => {
+  it("an empty query keeps every session in input order", () => {
+    const candidates = sessionBarCandidates([session("a"), session("b")]);
+    expect(barRows("", candidates).map((r) => r.candidate.session.id)).toEqual(["a", "b"]);
+  });
+
+  it("groups by kind without reordering the ranking", () => {
+    const candidates = sessionBarCandidates([
+      session("worker", { metadata: { name: "worker" }, current_cwd: "/home/me/dev/api" }),
+      session("api", { metadata: { name: "api" }, current_cwd: "/home/me/dev/web" }),
+    ]);
+    const rows = barRows("api", candidates);
+    const groups = barGroups(rows);
+    expect(groups).toHaveLength(1);
+    expect(groups[0].title).toBe("Sessions");
+    expect(groups[0].results.map((r) => r.candidate.session.id)).toEqual(
+      rows.map((r) => r.candidate.session.id),
+    );
+    // F6: the name beats the directory, and the directory match highlights
+    // inside the directory.
+    expect(groups[0].results[0].candidate.session.id).toBe("api");
+    expect(groups[0].results[1].field).toBe("directory");
+  });
+});
+
+describe("the overlay", () => {
+  const sessions = [
+    session("api", {
+      metadata: { name: "api" },
+      current_cwd: "/home/me/dev/api",
+      last_focused_at: "2026-01-01T11:00:00Z",
+    }),
+    session("worker", {
+      metadata: { name: "worker" },
+      current_cwd: "/home/me/dev/worker",
+      last_focused_at: "2026-01-01T10:00:00Z",
+    }),
+    session("notes", { metadata: { name: "notes" }, current_cwd: "/home/me/notes" }),
+  ];
+
+  // Sessions only: the mixed list's command half is the sigil describe's
+  // business, and the registry is whatever another test file happened to bind.
+  function open(over: Parameters<typeof openCommandBar>[0] | null = null) {
+    return openCommandBar(
+      over ?? { sessions, homeDir: "/home/me", commands: [], onOpenSession: () => {} },
+    );
+  }
+
+  it("is a registry command, so the help overlay lists it", () => {
+    const spec = COMMAND_SPECS.find((s) => s.id === "bar.open");
+    expect(spec?.keys).toEqual(["ctrl-k"]);
+    expect(spec?.scope).toBe("global");
+  });
+
+  it("lists sessions by recency under a kind header on an empty query", () => {
+    open();
+    expect([...document.querySelectorAll(".cmdbar-group-title")].map((h) => h.textContent)).toEqual([
+      "Sessions",
+    ]);
+    expect(rowNames()).toEqual(["api", "worker", "notes"]);
+    expect(activeName()).toBe("api");
+  });
+
+  it("opening twice leaves one overlay", () => {
+    open();
+    open();
+    expect(document.querySelectorAll(".cmdbar-overlay")).toHaveLength(1);
+    expect(isCommandBarOpen()).toBe(true);
+  });
+
+  it("ranks a typed query through the matcher and highlights the matched range", () => {
+    open();
+    type("wor");
+    expect(rowNames()).toEqual(["worker"]);
+    const marks = [...document.querySelectorAll(".cmdbar-row-name mark")].map((m) => m.textContent);
+    expect(marks).toEqual(["wor"]);
+  });
+
+  it("highlights inside the directory when that is the field that matched", () => {
+    open();
+    type("notes");
+    const row = document.querySelector(".cmdbar-row") as HTMLElement;
+    expect(row.dataset.sessionId).toBe("notes");
+    type("dev/wor");
+    expect(rowNames()).toEqual(["worker"]);
+    expect(
+      [...document.querySelectorAll(".cmdbar-row-meta mark")].map((m) => m.textContent).join(""),
+    ).toBe("dev/wor");
+  });
+
+  it("renders a no-results state rather than an empty list", () => {
+    open();
+    type("zzz");
+    expect(rowNames()).toEqual([]);
+    expect(document.querySelector(".cmdbar-empty")?.textContent).toBe("No matches");
+  });
+
+  it("moves the highlight with the arrows and ctrl-p/ctrl-n, without wrapping", () => {
+    open();
+    press("ArrowUp");
+    expect(activeName()).toBe("api");
+    press("ArrowDown");
+    expect(activeName()).toBe("worker");
+    press("n", { ctrlKey: true });
+    expect(activeName()).toBe("notes");
+    press("ArrowDown");
+    expect(activeName()).toBe("notes");
+    press("p", { ctrlKey: true });
+    expect(activeName()).toBe("worker");
+  });
+
+  it("puts the highlight back on the best row whenever the query changes", () => {
+    open();
+    press("ArrowDown");
+    expect(activeName()).toBe("worker");
+    type("o");
+    expect(activeName()).toBe(document.querySelector(".cmdbar-row-name")?.textContent);
+  });
+
+  it("opens the highlighted session through the shared open path on Enter", () => {
+    const seen: string[] = [];
+    const listener = (e: Event) => seen.push((e as CustomEvent<string>).detail);
+    document.addEventListener(SESSION_SELECT_EVENT, listener);
+    openCommandBar({ sessions, homeDir: "/home/me", commands: [] });
+    press("ArrowDown");
+    press("Enter");
+    document.removeEventListener(SESSION_SELECT_EVENT, listener);
+    expect(seen).toEqual(["worker"]);
+    expect(isCommandBarOpen()).toBe(false);
+  });
+
+  it("Enter on an empty result list does nothing", () => {
+    const onOpenSession = vi.fn();
+    open({ sessions, homeDir: "/home/me", commands: [], onOpenSession });
+    type("zzz");
+    press("Enter");
+    expect(onOpenSession).not.toHaveBeenCalled();
+    expect(isCommandBarOpen()).toBe(true);
+  });
+
+  it("closes on Escape and on a press outside the panel", () => {
+    open();
+    press("Escape");
+    expect(isCommandBarOpen()).toBe(false);
+
+    open();
+    (document.querySelector(".cmdbar-overlay") as HTMLElement).dispatchEvent(
+      new MouseEvent("mousedown", { bubbles: true }),
+    );
+    expect(isCommandBarOpen()).toBe(false);
+  });
+
+  it("stays open for a press inside the panel", () => {
+    open();
+    (document.querySelector(".cmdbar-panel") as HTMLElement).dispatchEvent(
+      new MouseEvent("mousedown", { bubbles: true }),
+    );
+    expect(isCommandBarOpen()).toBe(true);
+  });
+
+  it("returns the keyboard to whatever held it when it opened", () => {
+    const before = document.createElement("button");
+    document.body.appendChild(before);
+    before.focus();
+    open();
+    expect(document.activeElement).toBe(document.querySelector(".cmdbar-input"));
+    press("Escape");
+    expect(document.activeElement).toBe(before);
+  });
+
+  it("clicking a row opens that session", () => {
+    const onOpenSession = vi.fn();
+    open({ sessions, homeDir: "/home/me", commands: [], onOpenSession });
+    (document.querySelectorAll(".cmdbar-row")[1] as HTMLElement).click();
+    expect(onOpenSession).toHaveBeenCalledWith("worker");
+    expect(isCommandBarOpen()).toBe(false);
+  });
+});
+
+// ---- the sigils (#150) ----
+
+function command(id: string, label: string, keys: string[], run = () => {}): Command {
+  return { id, label, group: "Test", keys, scope: "global", run };
+}
+
+const flush = () => new Promise((resolve) => setTimeout(resolve, 0));
+
+function rowKeys(): string[][] {
+  return [...document.querySelectorAll(".cmdbar-row-keys")].map((el) =>
+    [...el.querySelectorAll("kbd")].map((k) => k.textContent ?? ""),
+  );
+}
+
+describe("parsing the query line", () => {
+  it("reads a sigil only in first position", () => {
+    expect(parseBarQuery(">kill")).toEqual({ sigil: ">", query: "kill" });
+    expect(parseBarQuery("~/dev")).toEqual({ sigil: "~", query: "/dev" });
+    expect(parseBarQuery("")).toEqual({ sigil: null, query: "" });
+    expect(parseBarQuery("api")).toEqual({ sigil: null, query: "api" });
+  });
+
+  it("leaves a sigil character elsewhere in the query literal", () => {
+    expect(parseBarQuery("api>x")).toEqual({ sigil: null, query: "api>x" });
+    // The case that matters: the second `~` of a directory query reaches the
+    // matcher.
+    expect(parseBarQuery("~~/dev")).toEqual({ sigil: "~", query: "~/dev" });
+  });
+
+  it("returns to the mixed list when the sigil is backspaced away", () => {
+    expect(parseBarQuery(">").sigil).toBe(">");
+    expect(parseBarQuery("").sigil).toBeNull();
+  });
+});
+
+describe("command candidates", () => {
+  it("dedupes by action, not by chord", () => {
+    const run = () => {};
+    const kill = command("a.kill", "Kill the session", ["x"], run);
+    const alias = command("b.kill", "Kill the session", ["ctrl-x"], run);
+    const other = command("c.rename", "Rename the session", ["r"]);
+    expect(dedupeCommands([kill, alias, other]).map((c) => c.id)).toEqual(["a.kill", "c.rename"]);
+  });
+
+  it("matches on the label only, and keeps the chord for display", () => {
+    const candidates = commandBarCandidates([command("a", "Open the spawn form", ["ctrl-k"])]);
+    expect(candidates[0].fields).toEqual({ label: "Open the spawn form" });
+    expect(candidates[0].command.keys).toEqual(["ctrl-k"]);
+  });
+});
+
+describe("directory candidates", () => {
+  it("abbreviates the path it shows and keeps the one it spawns in", () => {
+    const c = directoryCandidate("/home/me/dev/api", "/home/me");
+    expect(c).toEqual({ kind: "directory", path: "/home/me/dev/api", fields: { path: "~/dev/api" } });
+  });
+
+  it("expands a typed `~` and dedupes by the directory spawned in", () => {
+    const paths = ["~/dev/api", "/home/me/dev/api", "/tmp/scratch"];
+    expect(directoryBarCandidates(paths, "/home/me").map((c) => c.path)).toEqual([
+      "/home/me/dev/api",
+      "/tmp/scratch",
+    ]);
+  });
+});
+
+describe("the sigils in the overlay", () => {
+  const sessions = [session("api", { metadata: { name: "api" }, current_cwd: "/home/me/dev/api" })];
+  const ran: string[] = [];
+  const commands = [
+    command("spawn.open", "Open the spawn form", ["n"], () => ran.push("spawn.open")),
+    command("list.kill", "Kill the highlighted session", ["x"], () => ran.push("list.kill")),
+  ];
+
+  afterEach(() => {
+    ran.length = 0;
+  });
+
+  function open(over: Partial<Parameters<typeof openCommandBar>[0]> = {}) {
+    return openCommandBar({
+      sessions,
+      homeDir: "/home/me",
+      commands,
+      onOpenSession: () => {},
+      loadDirectories: async () => [],
+      listDirEntries: async () => [],
+      onSpawnDirectory: () => {},
+      ...over,
+    });
+  }
+
+  it("lists every command in registry order under `>`, with its chord and no header", () => {
+    open();
+    type(">");
+    expect(rowNames()).toEqual(["Open the spawn form", "Kill the highlighted session"]);
+    expect(rowKeys()).toEqual([["n"], ["x"]]);
+    expect(document.querySelectorAll(".cmdbar-group-title")).toHaveLength(0);
+  });
+
+  it("matches a command on its label and never on its chord", () => {
+    open();
+    type(">kill");
+    expect(rowNames()).toEqual(["Kill the highlighted session"]);
+    // `n` and `x` are chords, not label text: querying one finds nothing that
+    // the label does not also justify.
+    type(">ctrlx");
+    expect(rowNames()).toEqual([]);
+  });
+
+  it("runs the highlighted command on Enter", () => {
+    open();
+    type(">kill");
+    press("Enter");
+    expect(ran).toEqual(["list.kill"]);
+    expect(isCommandBarOpen()).toBe(false);
+  });
+
+  it("keeps the list mixed with no sigil, and returns to it when the sigil goes", () => {
+    open();
+    type("s");
+    expect([...document.querySelectorAll(".cmdbar-group-title")].map((h) => h.textContent)).toEqual([
+      "Sessions",
+      "Commands",
+    ]);
+    type(">spawn");
+    expect(rowNames()).toEqual(["Open the spawn form"]);
+    // Backspacing the sigil away is ordinary editing.
+    type("spawn");
+    expect(rowNames()).toContain("Open the spawn form");
+    type("");
+    expect(rowNames()).toEqual(["api"]);
+  });
+
+  it("lists recent dirs then projects under `~`", async () => {
+    open({ loadDirectories: async () => ["/home/me/dev/api", "/srv/www"] });
+    type("~");
+    await flush();
+    expect(rowNames()).toEqual(["~/dev/api", "/srv/www"]);
+    expect(document.querySelectorAll(".cmdbar-group-title")).toHaveLength(0);
+  });
+
+  it("fills the list in from /api/dirs as a path is typed", async () => {
+    const asked: string[] = [];
+    open({
+      loadDirectories: async () => ["/home/me/notes"],
+      listDirEntries: async (dir) => {
+        asked.push(dir);
+        return ["maestro", "api"];
+      },
+    });
+    // The second `~` is a literal query character and reaches the matcher.
+    type("~~/dev/mae");
+    await flush();
+    expect(asked).toEqual(["~/dev/"]);
+    expect(rowNames()).toEqual(["~/dev/maestro"]);
+  });
+
+  it("spawns in the highlighted directory on Enter", async () => {
+    const spawned: string[] = [];
+    open({
+      loadDirectories: async () => ["~/dev/api"],
+      onSpawnDirectory: (path) => spawned.push(path),
+    });
+    type("~api");
+    await flush();
+    press("Enter");
+    expect(spawned).toEqual(["/home/me/dev/api"]);
+    expect(isCommandBarOpen()).toBe(false);
+  });
+
+  it("raises the spawn event when the caller supplies no handler", async () => {
+    const seen: string[] = [];
+    const listener = (e: Event) => seen.push((e as CustomEvent<string>).detail);
+    document.addEventListener(SPAWN_DIRECTORY_EVENT, listener);
+    openCommandBar({
+      sessions,
+      homeDir: "/home/me",
+      commands,
+      onOpenSession: () => {},
+      loadDirectories: async () => ["/home/me/dev/api"],
+      listDirEntries: async () => [],
+    });
+    type("~");
+    await flush();
+    press("Enter");
+    document.removeEventListener(SPAWN_DIRECTORY_EVENT, listener);
+    expect(seen).toEqual(["/home/me/dev/api"]);
+  });
+});
+
+describe("the focus round-trip over a pane (#152)", () => {
+  function terminalTextarea(): HTMLTextAreaElement {
+    const ta = document.createElement("textarea");
+    ta.className = "xterm-helper-textarea";
+    document.body.appendChild(ta);
+    return ta;
+  }
+
+  it("hands the keyboard back to the terminal that had it", () => {
+    const ta = terminalTextarea();
+    ta.focus();
+    openCommandBar({ sessions: [], commands: [] });
+    expect(document.activeElement).toBe(document.querySelector(".cmdbar-input"));
+    press("Escape");
+    expect(document.activeElement).toBe(ta);
+  });
+
+  it("reports no focus change to the daemon, opening or closing", () => {
+    const fetchMock = vi.fn(() => Promise.resolve(new Response(null, { status: 204 })));
+    vi.stubGlobal("fetch", fetchMock);
+    try {
+      const ta = terminalTextarea();
+      ta.focus();
+      openCommandBar({ sessions: [], commands: [] });
+      press("Escape");
+      const focusCalls = fetchMock.mock.calls.filter(([url]: unknown[]) =>
+        String(url).includes("/focus"),
+      );
+      expect(focusCalls).toEqual([]);
+    } finally {
+      vi.unstubAllGlobals();
+    }
+  });
+});

web/src/commandBar.ts

@@ -0,0 +1,667 @@
+// The `ctrl-k` command bar (docs/COMMAND-BAR.md): a query line over a result
+// list, opened from the sidebar, closed with Escape.
+//
+// Three kinds live here: sessions and commands, ranked together by default,
+// and directories, which need the `~` sigil. The action page and the
+// terminal-focus binding land in #151-#152.
+
+import { listDir, projects as fetchProjects, recentDirs } from "./api.js";
+import { SESSION_SELECT_EVENT } from "./catalog.js";
+import { keyCaps, publishedCommands, type Command } from "./commands.js";
+import {
+  matchAndRank,
+  type CandidateKind,
+  type CommandCandidate,
+  type DirectoryCandidate,
+  type MatchRange,
+  type MatchResult,
+  type SessionCandidate,
+} from "./matcher.js";
+import { splitPath } from "./paths.js";
+import { splitCommand } from "./toolIcon.js";
+import { abbreviateCwd, sessionName, sessionTreePath, type Session } from "./types.js";
+
+/** A matcher candidate that remembers what it came from, so a result can be
+ *  acted on without a second lookup. The extra property is invisible to the
+ *  matcher, which only ever reads `kind` and `fields`. */
+export type SessionBarCandidate = SessionCandidate & { session: Session };
+export type CommandBarCandidate = CommandCandidate & { command: Command };
+/** `fields.path` is the abbreviated path the operator reads and the matcher
+ *  ranks; `path` is the one a spawn is made in. */
+export type DirectoryBarCandidate = DirectoryCandidate & { path: string };
+
+export type BarCandidate = SessionBarCandidate | CommandBarCandidate | DirectoryBarCandidate;
+export type BarResult = MatchResult<BarCandidate>;
+
+/** Raised when Enter lands on a directory row. The bar picks the directory; the
+ *  shell owns the spawn, which is the same fast-forward path `N` takes. */
+export const SPAWN_DIRECTORY_EVENT = "cmdbar-spawn-directory";
+
+/** One kind's slice of the ranked list, in rank order. */
+export interface BarGroup<C extends BarCandidate = BarCandidate> {
+  kind: CandidateKind;
+  title: string;
+  results: MatchResult<C>[];
+}
+
+const KIND_TITLES: Record<CandidateKind, string> = {
+  session: "Sessions",
+  command: "Commands",
+  directory: "Directories",
+};
+
+// ---- the sigils ----
+
+export type BarSigil = ">" | "~";
+
+export interface BarQuery {
+  /** The sigil in force, or null for the mixed list. */
+  sigil: BarSigil | null;
+  /** What the matcher sees: everything after a sigil, or the whole query. */
+  query: string;
+}
+
+/** Split a raw query line into its sigil and the query proper.
+ *
+ *  A sigil is only a sigil in first position: `>` or `~` anywhere else is a
+ *  literal query character, which is what a directory query with a second `~`
+ *  in it depends on. Backspacing past a sigil needs no special case either —
+ *  the first character goes and the query is a mixed one again. */
+export function parseBarQuery(raw: string): BarQuery {
+  const first = raw[0];
+  if (first === ">" || first === "~") return { sigil: first, query: raw.slice(1) };
+  return { sigil: null, query: raw };
+}
+
+// ---- candidates ----
+
+function focusedAt(s: Session): number | null {
+  const stamp = s.last_focused_at;
+  if (typeof stamp !== "string" || stamp === "") return null;
+  const ms = Date.parse(stamp);
+  return Number.isNaN(ms) ? null : ms;
+}
+
+function createdAt(s: Session): number {
+  const ms = Date.parse(s.created_at ?? "");
+  return Number.isNaN(ms) ? 0 : ms;
+}
+
+/** The empty-query order (docs/COMMAND-BAR.md, "Empty query"): most recently
+ *  focused first; a session that has never been focused sorts after every
+ *  session that has, most recently created first among those; and a dead
+ *  session sorts after every live one regardless of recency, because a session
+ *  you cannot attach to is not where you just were.
+ *
+ *  This is also the input order for a non-empty query, which is what the
+ *  matcher's last tie-break preserves. */
+export function orderSessionsForBar(sessions: readonly Session[]): Session[] {
+  return [...sessions].sort((a, b) => {
+    const deadA = a.status === "Dead" ? 1 : 0;
+    const deadB = b.status === "Dead" ? 1 : 0;
+    if (deadA !== deadB) return deadA - deadB;
+
+    const focusA = focusedAt(a);
+    const focusB = focusedAt(b);
+    if ((focusA === null) !== (focusB === null)) return focusA === null ? 1 : -1;
+    if (focusA !== null && focusB !== null && focusA !== focusB) return focusB - focusA;
+
+    return createdAt(b) - createdAt(a);
+  });
+}
+
+/** Build one session's candidate: the fields docs/COMMAND-BAR.md's candidate
+ *  table names, with the directory abbreviated the way the sidebar shows it. */
+export function sessionCandidate(s: Session, homeDir?: string): SessionBarCandidate {
+  const treePath = sessionTreePath(s);
+  const directory = treePath ? abbreviateCwd(treePath, homeDir) : undefined;
+  const tool = splitCommand(s.command).tool ?? undefined;
+  return {
+    kind: "session",
+    session: s,
+    fields: {
+      name: sessionName(s),
+      ...(directory ? { directory } : {}),
+      ...(s.command ? { command: s.command } : {}),
+      ...(tool ? { tool } : {}),
+    },
+  };
+}
+
+/** Every session as a candidate, in the empty-query order. */
+export function sessionBarCandidates(
+  sessions: readonly Session[],
+  homeDir?: string,
+): SessionBarCandidate[] {
+  return orderSessionsForBar(sessions).map((s) => sessionCandidate(s, homeDir));
+}
+
+/** Drop the commands that would list twice. Several chords can be bound to one
+ *  action — the registry already carries its aliases on one entry, but nothing
+ *  stops two entries running the same handler, and listed naively that is two
+ *  identical rows. The dedupe is by **action**, never by chord: the chord is
+ *  displayed, so a command with two of them is still one row. */
+export function dedupeCommands(commands: readonly Command[]): Command[] {
+  const seenRun = new Set<Command["run"]>();
+  const seenLabel = new Set<string>();
+  const kept: Command[] = [];
+  for (const command of commands) {
+    if (seenRun.has(command.run) || seenLabel.has(command.label)) continue;
+    seenRun.add(command.run);
+    seenLabel.add(command.label);
+    kept.push(command);
+  }
+  return kept;
+}
+
+/** Every bound command as a candidate, in registry order. Only the label is a
+ *  field: the chord is displayed beside the row, never matched, because
+ *  matching it would make `>` results depend on a user's rebinds. */
+export function commandBarCandidates(commands: readonly Command[]): CommandBarCandidate[] {
+  return dedupeCommands(commands).map((command) => ({
+    kind: "command",
+    command,
+    fields: { label: command.label },
+  }));
+}
+
+/** `~/dev/api` back to `/home/me/dev/api` — the inverse of `abbreviateCwd`, for
+ *  a path the operator typed or `/api/dirs` completed. */
+export function expandHome(path: string, homeDir?: string): string {
+  if (!homeDir) return path;
+  if (path === "~") return homeDir;
+  return path.startsWith("~/") ? `${homeDir}${path.slice(1)}` : path;
+}
+
+export function directoryCandidate(path: string, homeDir?: string): DirectoryBarCandidate {
+  const absolute = expandHome(path, homeDir);
+  return { kind: "directory", path: absolute, fields: { path: abbreviateCwd(absolute, homeDir) } };
+}
+
+/** Candidates for `~`, deduped by the directory they spawn in and keeping the
+ *  first mention of each — recent dirs (newest first) ahead of the project
+ *  list, which is the empty-query order the contract asks for. */
+export function directoryBarCandidates(
+  paths: readonly string[],
+  homeDir?: string,
+): DirectoryBarCandidate[] {
+  const seen = new Set<string>();
+  const out: DirectoryBarCandidate[] = [];
+  for (const path of paths) {
+    if (path === "") continue;
+    const candidate = directoryCandidate(path, homeDir);
+    if (seen.has(candidate.path)) continue;
+    seen.add(candidate.path);
+    out.push(candidate);
+  }
+  return out;
+}
+
+/** The directory list the bar starts from: what the spawn form already knows —
+ *  `GET /api/recent-dirs` and the project list — either alone if the other
+ *  fails. */
+export async function loadBarDirectories(): Promise<string[]> {
+  const [recents, discovered] = await Promise.all([
+    recentDirs()
+      .then((r) => r.dirs.map((d) => d.cwd))
+      .catch(() => [] as string[]),
+    fetchProjects()
+      .then((list) => list.map((p) => p.path))
+      .catch(() => [] as string[]),
+  ]);
+  return [...recents, ...discovered];
+}
+
+// ---- grouping ----
+
+/** Bucket a ranked list by kind for rendering. Grouping is a rendering of the
+ *  ranking, never a reordering of it: a group holds its matches in rank order,
+ *  and groups appear in the order their best-scoring member does — so the first
+ *  row under the first header is the globally best result. */
+export function barGroups<C extends BarCandidate>(
+  results: readonly MatchResult<C>[],
+): BarGroup<C>[] {
+  const groups: BarGroup<C>[] = [];
+  for (const result of results) {
+    const kind = result.candidate.kind;
+    let group = groups.find((g) => g.kind === kind);
+    if (!group) {
+      group = { kind, title: KIND_TITLES[kind], results: [] };
+      groups.push(group);
+    }
+    group.results.push(result);
+  }
+  return groups;
+}
+
+/** The rows a query produces, flat and in rank order — what the highlight walks
+ *  and what Enter acts on. Headers are labels, not rows, so they are never in
+ *  this list. */
+export function barRows<C extends BarCandidate>(
+  query: string,
+  candidates: readonly C[],
+): MatchResult<C>[] {
+  return matchAndRank(query, candidates);
+}
+
+// ---- rendering ----
+
+/** Text with its matched ranges wrapped in `<mark>`. Ranges come from the
+ *  matcher as `[start, end)` character pairs over the field that won. */
+export function renderHighlighted(text: string, ranges: readonly MatchRange[]): DocumentFragment {
+  const frag = document.createDocumentFragment();
+  let cursor = 0;
+  for (const [start, end] of ranges) {
+    if (start > cursor) frag.append(text.slice(cursor, start));
+    const mark = document.createElement("mark");
+    mark.className = "cmdbar-hit";
+    mark.textContent = text.slice(start, end);
+    frag.append(mark);
+    cursor = end;
+  }
+  if (cursor < text.length) frag.append(text.slice(cursor));
+  return frag;
+}
+
+/** The name line of a row: the session's name, the command's label, or the
+ *  directory's path. */
+function rowName(candidate: BarCandidate): string {
+  switch (candidate.kind) {
+    case "session":
+      return candidate.fields.name;
+    case "command":
+      return candidate.fields.label;
+    case "directory":
+      return candidate.fields.path;
+  }
+}
+
+/** The secondary line under a session row: the field the match was found in
+ *  when that was not the name, so a session found through its directory says
+ *  so. Only sessions have one — a command shows keycaps instead, and a
+ *  directory's path is already the name. */
+function metaText(result: BarResult): string | undefined {
+  if (result.candidate.kind !== "session") return undefined;
+  const fields = result.candidate.fields;
+  switch (result.field) {
+    case "directory":
+      return fields.directory;
+    case "command":
+      return fields.command;
+    case "tool":
+      return fields.tool;
+    default:
+      return fields.directory;
+  }
+}
+
+function renderRow(result: BarResult, index: number): HTMLElement {
+  const candidate = result.candidate;
+  const row = document.createElement("div");
+  row.className = "cmdbar-row";
+  row.setAttribute("role", "option");
+  row.id = `cmdbar-row-${index}`;
+  row.dataset.index = String(index);
+  row.dataset.kind = candidate.kind;
+  if (candidate.kind === "session") {
+    row.dataset.sessionId = candidate.session.id;
+    if (candidate.session.status === "Dead") row.classList.add("is-dead");
+  } else if (candidate.kind === "command") {
+    row.dataset.commandId = candidate.command.id;
+  } else {
+    row.dataset.path = candidate.path;
+  }
+
+  const name = document.createElement("span");
+  name.className = "cmdbar-row-name";
+  const nameText = rowName(candidate);
+  const nameMatched =
+    result.field === "name" || result.field === "label" || result.field === "path";
+  name.append(nameMatched ? renderHighlighted(nameText, result.ranges) : nameText);
+  row.appendChild(name);
+
+  // The chord is teaching material, not a match target: it is rendered from
+  // the live registry entry and never fed to the matcher.
+  if (candidate.kind === "command") {
+    const keys = document.createElement("span");
+    keys.className = "cmdbar-row-keys";
+    for (const cap of keyCaps(candidate.command.keys[0])) {
+      const kbd = document.createElement("kbd");
+      kbd.textContent = cap;
+      keys.appendChild(kbd);
+    }
+    row.appendChild(keys);
+    return row;
+  }
+
+  const meta = metaText(result);
+  if (meta) {
+    const el = document.createElement("span");
+    el.className = "cmdbar-row-meta";
+    const highlighted = result.field !== undefined && result.field !== "name";
+    el.append(highlighted ? renderHighlighted(meta, result.ranges) : meta);
+    row.appendChild(el);
+  }
+  return row;
+}
+
+const PLACEHOLDERS: Record<"mixed" | BarSigil, string> = {
+  mixed: "Go to a session…",
+  ">": "Run a command…",
+  "~": "Spawn in a directory…",
+};
+
+// ---- the overlay ----
+
+export interface CommandBarOptions {
+  /** Sessions to build candidates from, as the store has them right now. */
+  sessions: readonly Session[];
+  /** The daemon's home dir, for the directory field's `~/…` abbreviation. */
+  homeDir?: string;
+  /** Open the highlighted session. Defaults to the shared open path — the
+   *  sidebar's click event — which is what the contract requires; tests pass
+   *  their own. */
+  onOpenSession?: (sessionId: string) => void;
+  /** The command registry to list under `>`. Defaults to every bound command,
+   *  in registry order. */
+  commands?: readonly Command[];
+  /** The directory list behind `~`, fetched once on first use. */
+  loadDirectories?: () => Promise<string[]>;
+  /** One directory's subdirectories, for filling the list in as a path is
+   *  typed. Defaults to `GET /api/dirs`. */
+  listDirEntries?: (dir: string) => Promise<string[]>;
+  /** Spawn a session in the highlighted directory. Defaults to raising
+   *  `SPAWN_DIRECTORY_EVENT`, which the shell turns into a fast-forward
+   *  spawn. */
+  onSpawnDirectory?: (path: string) => void;
+}
+
+interface OpenBar {
+  el: HTMLElement;
+  dispose: () => void;
+}
+
+let current: OpenBar | null = null;
+
+export function isCommandBarOpen(): boolean {
+  return current !== null;
+}
+
+export function closeCommandBar(): void {
+  current?.dispose();
+}
+
+/** Mount the bar. Opening while one is up replaces it, so a stray second call
+ *  can never stack two overlays. */
+export function openCommandBar(opts: CommandBarOptions): HTMLElement {
+  closeCommandBar();
+
+  // Closing returns the keyboard to whatever held it when the bar opened: a
+  // round trip through the bar never silently moves focus.
+  const previouslyFocused = document.activeElement as HTMLElement | null;
+  const openSession =
+    opts.onOpenSession ??
+    ((id: string) => document.dispatchEvent(new CustomEvent(SESSION_SELECT_EVENT, { detail: id })));
+  const spawnDirectory =
+    opts.onSpawnDirectory ??
+    ((path: string) =>
+      document.dispatchEvent(new CustomEvent(SPAWN_DIRECTORY_EVENT, { detail: path })));
+  const loadDirectories = opts.loadDirectories ?? loadBarDirectories;
+  const listEntries =
+    opts.listDirEntries ?? ((dir: string) => listDir(dir).then((listing) => listing.entries));
+
+  const sessionCandidates: SessionBarCandidate[] = sessionBarCandidates(
+    opts.sessions,
+    opts.homeDir,
+  );
+  const commandCandidates: CommandBarCandidate[] = commandBarCandidates(
+    opts.commands ?? publishedCommands(),
+  );
+
+  const el = document.createElement("div");
+  el.className = "cmdbar-overlay";
+  el.setAttribute("role", "dialog");
+  el.setAttribute("aria-modal", "true");
+  el.setAttribute("aria-label", "Command bar");
+
+  const panel = document.createElement("div");
+  panel.className = "cmdbar-panel";
+
+  const input = document.createElement("input");
+  input.type = "text";
+  input.className = "cmdbar-input";
+  input.setAttribute("role", "combobox");
+  input.setAttribute("aria-expanded", "true");
+  input.setAttribute("aria-controls", "cmdbar-results");
+  input.setAttribute("aria-label", "Search sessions, commands and directories");
+  input.setAttribute("autocomplete", "off");
+  input.spellcheck = false;
+  input.placeholder = PLACEHOLDERS.mixed;
+
+  const results = document.createElement("div");
+  results.className = "cmdbar-results";
+  results.id = "cmdbar-results";
+  results.setAttribute("role", "listbox");
+
+  panel.append(input, results);
+  el.appendChild(panel);
+  document.body.appendChild(el);
+
+  let rows: BarResult[] = [];
+  let highlighted = 0;
+
+  // `~`'s candidates: the recents-and-projects list, fetched once, plus
+  // whatever `/api/dirs` has filled in for the directory being typed.
+  let directories: DirectoryBarCandidate[] = [];
+  let directoriesRequested = false;
+  let probed: DirectoryBarCandidate[] = [];
+  let probedDir: string | null = null;
+  const listings = new Map<string, string[]>();
+
+  function alive(): boolean {
+    return current?.el === el;
+  }
+
+  /** Fetch the recents-and-projects list the first time `~` is used. */
+  function ensureDirectories(): void {
+    if (directoriesRequested) return;
+    directoriesRequested = true;
+    loadDirectories()
+      .then((paths) => {
+        directories = directoryBarCandidates(paths, opts.homeDir);
+        if (alive()) render();
+      })
+      .catch(() => {
+        /* no directories is a shorter list, not an error state */
+      });
+  }
+
+  /** Fill the list in from `GET /api/dirs` once the query looks like a path:
+   *  the directory it names is listed and its children join the candidates, so
+   *  `~` reaches a directory that was never spawned in. */
+  function probeDirectories(query: string): void {
+    const { dir } = splitPath(query);
+    if (dir === "") {
+      probed = [];
+      probedDir = null;
+      return;
+    }
+    if (dir === probedDir) return;
+    probedDir = dir;
+    const cached = listings.get(dir);
+    if (cached) {
+      probed = directoryBarCandidates(
+        cached.map((entry) => `${dir}${entry}`),
+        opts.homeDir,
+      );
+      return;
+    }
+    probed = [];
+    listEntries(dir)
+      .then((entries) => {
+        listings.set(dir, entries);
+        if (!alive() || probedDir !== dir) return;
+        probed = directoryBarCandidates(
+          entries.map((entry) => `${dir}${entry}`),
+          opts.homeDir,
+        );
+        render();
+      })
+      .catch(() => {
+        /* an unreadable directory contributes nothing */
+      });
+  }
+
+  /** What the matcher sees for the query line as it stands. With no sigil the
+   *  list is mixed — sessions and commands together — except on an empty query,
+   *  where the bar is a session switcher. */
+  function candidatesFor(parsed: BarQuery): BarCandidate[] {
+    switch (parsed.sigil) {
+      case ">":
+        return [...commandCandidates];
+      case "~": {
+        ensureDirectories();
+        probeDirectories(parsed.query);
+        const seen = new Set<string>();
+        return [...directories, ...probed].filter((c) =>
+          seen.has(c.path) ? false : (seen.add(c.path), true),
+        );
+      }
+      default:
+        return parsed.query === ""
+          ? [...sessionCandidates]
+          : [...sessionCandidates, ...commandCandidates];
+    }
+  }
+
+  function paintHighlight(): void {
+    for (const row of results.querySelectorAll<HTMLElement>(".cmdbar-row")) {
+      const active = Number(row.dataset.index) === highlighted;
+      row.classList.toggle("is-active", active);
+      row.setAttribute("aria-selected", active ? "true" : "false");
+      if (active) {
+        row.scrollIntoView({ block: "nearest" });
+        input.setAttribute("aria-activedescendant", row.id);
+      }
+    }
+    if (rows.length === 0) input.removeAttribute("aria-activedescendant");
+  }
+
+  function render(): void {
+    const parsed = parseBarQuery(input.value);
+    input.placeholder = PLACEHOLDERS[parsed.sigil ?? "mixed"];
+    rows = barRows(parsed.query, candidatesFor(parsed));
+    // The highlight starts on the globally best row every time the list
+    // changes: an old index would point at a different result.
+    highlighted = 0;
+    results.replaceChildren();
+
+    if (rows.length === 0) {
+      const empty = document.createElement("div");
+      empty.className = "cmdbar-empty";
+      empty.textContent = "No matches";
+      results.appendChild(empty);
+      paintHighlight();
+      return;
+    }
+
+    let index = 0;
+    for (const group of barGroups(rows)) {
+      // While a sigil is in force there is one kind, so the header is dropped.
+      if (parsed.sigil === null) {
+        const header = document.createElement("div");
+        header.className = "cmdbar-group-title";
+        header.setAttribute("role", "presentation");
+        header.textContent = group.title;
+        results.appendChild(header);
+      }
+      for (const result of group.results) {
+        const at = index;
+        const row = renderRow(result, at);
+        row.addEventListener("click", () => activate(at));
+        results.appendChild(row);
+        index += 1;
+      }
+    }
+    paintHighlight();
+  }
+
+  /** The highlight does not wrap: it stops at the first and last row. */
+  function move(delta: number): void {
+    if (rows.length === 0) return;
+    highlighted = Math.min(rows.length - 1, Math.max(0, highlighted + delta));
+    paintHighlight();
+  }
+
+  function activate(index: number): void {
+    const result = rows[index];
+    if (!result) return;
+    const candidate = result.candidate;
+    close();
+    switch (candidate.kind) {
+      case "session":
+        openSession(candidate.session.id);
+        return;
+      case "command":
+        candidate.command.run();
+        return;
+      case "directory":
+        spawnDirectory(candidate.path);
+        return;
+    }
+  }
+
+  function onKeydown(e: KeyboardEvent): void {
+    switch (e.key) {
+      case "Escape":
+        e.preventDefault();
+        close();
+        return;
+      case "Enter":
+        e.preventDefault();
+        activate(highlighted);
+        return;
+      case "ArrowDown":
+        e.preventDefault();
+        move(1);
+        return;
+      case "ArrowUp":
+        e.preventDefault();
+        move(-1);
+        return;
+      case "n":
+        if (e.ctrlKey) {
+          e.preventDefault();
+          move(1);
+        }
+        return;
+      case "p":
+        if (e.ctrlKey) {
+          e.preventDefault();
+          move(-1);
+        }
+        return;
+    }
+  }
+
+  function close(): void {
+    if (current?.el !== el) return;
+    current = null;
+    el.remove();
+    // Restoring focus is what makes the bar a view over the app rather than a
+    // place in it; a detached node cannot take it.
+    if (previouslyFocused?.isConnected) previouslyFocused.focus();
+  }
+
+  input.addEventListener("keydown", onKeydown);
+  input.addEventListener("input", render);
+  // A press on the scrim closes; one inside the panel is left alone.
+  el.addEventListener("mousedown", (ev) => {
+    if (!panel.contains(ev.target as Node)) close();
+  });
+
+  current = { el, dispose: close };
+  render();
+  input.focus();
+  return el;
+}

web/src/commands.test.ts

@@ -0,0 +1,309 @@
+// @vitest-environment happy-dom
+import { describe, expect, it, vi } from "vitest";
+
+import {
+  COMMAND_SPECS,
+  CommandSet,
+  DEFAULT_LEADER,
+  canonicalizeKey,
+  defineCommands,
+  isBarTypingTarget,
+  isTerminalTextarea,
+  isTypingTarget,
+  keyCaps,
+  publishedCommands,
+} from "./commands.js";
+
+function key(k: string, init: KeyboardEventInit = {}): KeyboardEvent {
+  return new KeyboardEvent("keydown", { key: k, cancelable: true, ...init });
+}
+
+function el(html: string): HTMLElement {
+  const d = document.createElement("div");
+  d.innerHTML = html;
+  return d.firstElementChild as HTMLElement;
+}
+
+/** Dispatch on a target, so `isTypingTarget` sees something other than null. */
+function pressOn(set: CommandSet, target: HTMLElement, k: string, init?: KeyboardEventInit): boolean {
+  const e = key(k, init);
+  Object.defineProperty(e, "target", { value: target });
+  return set.handle(e);
+}
+
+describe("command specs", () => {
+  it("has a unique id and at least one chord per command", () => {
+    const ids = COMMAND_SPECS.map((s) => s.id);
+    expect(new Set(ids).size).toBe(ids.length);
+    for (const spec of COMMAND_SPECS) {
+      expect(spec.keys.length).toBeGreaterThan(0);
+      expect(spec.label.length).toBeGreaterThan(0);
+    }
+  });
+
+  it("binds each chord once within a scope", () => {
+    const seen = new Set<string>();
+    for (const spec of COMMAND_SPECS) {
+      for (const k of spec.keys) {
+        const slot = `${spec.scope}:${k}`;
+        expect(seen.has(slot)).toBe(false);
+        seen.add(slot);
+      }
+    }
+  });
+
+  it("rejects a handler for an id that isn't in the registry", () => {
+    expect(() => defineCommands({ "nope.missing": () => {} })).toThrow(/unknown command id/);
+  });
+
+  it("carries every spec field onto the defined command", () => {
+    const [cmd] = defineCommands({ "spawn.open": () => {} });
+    expect(cmd).toMatchObject({ id: "spawn.open", keys: ["n"], scope: "global" });
+  });
+});
+
+describe("canonicalizeKey", () => {
+  it("spells keys the way the TUI's InputKey::canonical does", () => {
+    expect(canonicalizeKey(key("n"))).toBe("n");
+    expect(canonicalizeKey(key("N", { shiftKey: true }))).toBe("N");
+    expect(canonicalizeKey(key("?", { shiftKey: true }))).toBe("?");
+    expect(canonicalizeKey(key("a", { ctrlKey: true }))).toBe("ctrl-a");
+    expect(canonicalizeKey(key("Escape"))).toBe("esc");
+    expect(canonicalizeKey(key("Enter"))).toBe("enter");
+    expect(canonicalizeKey(key("Tab"))).toBe("tab");
+    expect(canonicalizeKey(key("Tab", { shiftKey: true }))).toBe("backtab");
+    expect(canonicalizeKey(key("ArrowDown"))).toBe("down");
+  });
+
+  it("folds a modified letter to lower case with an explicit shift-", () => {
+    expect(canonicalizeKey(key("H", { ctrlKey: true, shiftKey: true }))).toBe("ctrl-shift-h");
+    expect(canonicalizeKey(key("h", { ctrlKey: true, shiftKey: true }))).toBe("ctrl-shift-h");
+  });
+
+  it("has no canonical form for a modifier pressed alone", () => {
+    expect(canonicalizeKey(key("Control", { ctrlKey: true }))).toBeNull();
+    expect(canonicalizeKey(key("Shift", { shiftKey: true }))).toBeNull();
+  });
+});
+
+describe("keyCaps", () => {
+  it("renders one cap per modifier and key", () => {
+    expect(keyCaps("ctrl-shift-h")).toEqual(["Ctrl", "Shift", "H"]);
+    expect(keyCaps("enter")).toEqual(["Enter"]);
+    expect(keyCaps("j")).toEqual(["j"]);
+    expect(keyCaps("N")).toEqual(["N"]);
+    expect(keyCaps("?")).toEqual(["?"]);
+    expect(keyCaps("ctrl-a ctrl-k")).toEqual(["Ctrl", "A", "then", "Ctrl", "K"]);
+  });
+});
+
+describe("CommandSet", () => {
+  it("runs the command bound to a chord, and swallows the browser default", () => {
+    const run = vi.fn();
+    const set = new CommandSet(defineCommands({ "spawn.open": run }));
+    const e = key("n");
+    expect(set.handle(e)).toBe(true);
+    expect(run).toHaveBeenCalledTimes(1);
+    expect(e.defaultPrevented).toBe(true);
+  });
+
+  it("leaves an unbound key alone", () => {
+    const set = new CommandSet(defineCommands({ "spawn.open": vi.fn() }));
+    const e = key("q");
+    expect(set.handle(e)).toBe(false);
+    expect(e.defaultPrevented).toBe(false);
+  });
+
+  it("treats a modified key as a different binding", () => {
+    const run = vi.fn();
+    const set = new CommandSet(defineCommands({ "spawn.open": run }));
+    expect(set.handle(key("n", { ctrlKey: true }))).toBe(false);
+    expect(set.handle(key("n", { metaKey: true }))).toBe(false);
+    expect(run).not.toHaveBeenCalled();
+  });
+
+  it("runs every alias of a command", () => {
+    const run = vi.fn();
+    const set = new CommandSet(defineCommands({ "list.next": run }));
+    set.handle(key("j"));
+    set.handle(key("ArrowDown"));
+    expect(run).toHaveBeenCalledTimes(2);
+  });
+
+  it("keeps plain keys deaf inside a form field, and chorded ones live", () => {
+    const plain = vi.fn();
+    const chorded = vi.fn();
+    const set = new CommandSet(
+      defineCommands({ "spawn.open": plain, "focus.toggle": chorded }),
+    );
+    const input = el("<input>");
+    expect(pressOn(set, input, "n")).toBe(false);
+    expect(plain).not.toHaveBeenCalled();
+    expect(pressOn(set, input, "H", { ctrlKey: true, shiftKey: true })).toBe(true);
+    expect(chorded).toHaveBeenCalledTimes(1);
+  });
+
+  it("keeps pane commands live inside the terminal's textarea", () => {
+    const run = vi.fn();
+    const set = new CommandSet(defineCommands({ "pane.focusList": run }), {
+      preventDefault: false,
+    });
+    const textarea = el('<textarea class="xterm-helper-textarea"></textarea>');
+    const e = key("Escape");
+    Object.defineProperty(e, "target", { value: textarea });
+    expect(set.handle(e)).toBe(true);
+    expect(run).toHaveBeenCalledTimes(1);
+    // xterm is told to swallow by the return value, not by the browser default.
+    expect(e.defaultPrevented).toBe(false);
+  });
+});
+
+describe("the leader", () => {
+  it("defaults to the TUI's ctrl-a", () => {
+    expect(DEFAULT_LEADER).toBe("ctrl-a");
+  });
+
+  it("holds the leader as a partial chord instead of selecting the page", () => {
+    const set = new CommandSet(defineCommands({ "spawn.open": vi.fn() }), {
+      leader: DEFAULT_LEADER,
+    });
+    const e = key("a", { ctrlKey: true });
+    expect(set.handle(e)).toBe(true);
+    expect(e.defaultPrevented).toBe(true);
+  });
+
+  it("swallows the key after the leader rather than running its plain binding", () => {
+    const run = vi.fn();
+    const set = new CommandSet(defineCommands({ "spawn.open": run }), {
+      leader: DEFAULT_LEADER,
+    });
+    set.handle(key("a", { ctrlKey: true }));
+    expect(set.handle(key("n"))).toBe(true);
+    expect(run).not.toHaveBeenCalled();
+    // The next key is an ordinary one again.
+    set.handle(key("n"));
+    expect(run).toHaveBeenCalledTimes(1);
+  });
+
+  it("forgets a held leader once the chord timeout passes", () => {
+    const run = vi.fn();
+    let now = 0;
+    const set = new CommandSet(defineCommands({ "spawn.open": run }), {
+      leader: DEFAULT_LEADER,
+      chordTimeoutMs: 1000,
+      now: () => now,
+    });
+    set.handle(key("a", { ctrlKey: true }));
+    now = 1500;
+    set.handle(key("n"));
+    expect(run).toHaveBeenCalledTimes(1);
+  });
+
+  it("leaves select-all alone in a real form field", () => {
+    const set = new CommandSet(defineCommands({ "spawn.open": vi.fn() }), {
+      leader: DEFAULT_LEADER,
+    });
+    const input = el("<input>");
+    const e = key("a", { ctrlKey: true });
+    Object.defineProperty(e, "target", { value: input });
+    expect(set.handle(e)).toBe(false);
+    expect(e.defaultPrevented).toBe(false);
+  });
+});
+
+describe("publishing", () => {
+  it("lists a constructed set's commands, replacing an id rather than doubling it", () => {
+    new CommandSet(defineCommands({ "list.kill": () => {} }));
+    new CommandSet(defineCommands({ "list.kill": () => {} }));
+    const ids = publishedCommands().map((c) => c.id);
+    expect(ids.filter((id) => id === "list.kill")).toEqual(["list.kill"]);
+  });
+
+  it("keeps published commands in registry order", () => {
+    const order = COMMAND_SPECS.map((s) => s.id);
+    const ids = publishedCommands().map((c) => c.id);
+    expect(ids).toEqual(order.filter((id) => ids.includes(id)));
+  });
+});
+
+describe("isTypingTarget", () => {
+  it("is true for form fields and editable nodes, false otherwise", () => {
+    expect(isTypingTarget(el("<input>"))).toBe(true);
+    expect(isTypingTarget(el("<textarea></textarea>"))).toBe(true);
+    expect(isTypingTarget(el("<select></select>"))).toBe(true);
+    expect(isTypingTarget(el('<div contenteditable="true"></div>'))).toBe(true);
+    expect(isTypingTarget(el("<button></button>"))).toBe(false);
+    expect(isTypingTarget(null)).toBe(false);
+  });
+});
+
+describe("isTerminalTextarea", () => {
+  it("recognises xterm's offscreen textarea, and nothing else", () => {
+    expect(isTerminalTextarea(el('<textarea class="xterm-helper-textarea"></textarea>'))).toBe(true);
+    expect(isTerminalTextarea(el("<textarea></textarea>"))).toBe(false);
+    expect(isTerminalTextarea(el("<input>"))).toBe(false);
+    expect(isTerminalTextarea(null)).toBe(false);
+  });
+});
+
+describe("isBarTypingTarget", () => {
+  it("holds the bar's keys out of real form fields", () => {
+    expect(isBarTypingTarget(el("<input>"))).toBe(true);
+    expect(isBarTypingTarget(el("<textarea></textarea>"))).toBe(true);
+  });
+
+  it("does not count the terminal's textarea, so ctrl-k reaches the bar there", () => {
+    expect(isBarTypingTarget(el('<textarea class="xterm-helper-textarea"></textarea>'))).toBe(false);
+    expect(isBarTypingTarget(el("<button></button>"))).toBe(false);
+    expect(isBarTypingTarget(null)).toBe(false);
+  });
+});
+
+describe("ctrl-k over a focused pane (#152)", () => {
+  const terminal = () => el('<textarea class="xterm-helper-textarea"></textarea>');
+
+  /** The global listener's routing: the bar's set only sees a key that is not
+   *  aimed at a real form field. */
+  function route(set: CommandSet, target: HTMLElement, k: string, init?: KeyboardEventInit) {
+    if (isBarTypingTarget(target)) return false;
+    return pressOn(set, target, k, init);
+  }
+
+  it("opens the bar when the terminal has the keyboard", () => {
+    const open = vi.fn();
+    const set = new CommandSet(defineCommands({ "bar.open": open }));
+    expect(route(set, terminal(), "k", { ctrlKey: true })).toBe(true);
+    expect(open).toHaveBeenCalledTimes(1);
+  });
+
+  it("leaves the spawn form's inputs their own Ctrl-K", () => {
+    const open = vi.fn();
+    const set = new CommandSet(defineCommands({ "bar.open": open }));
+    expect(route(set, el("<input>"), "k", { ctrlKey: true })).toBe(false);
+    expect(open).not.toHaveBeenCalled();
+  });
+
+  it("sends the literal 0x0B after the leader, without opening the bar", () => {
+    const open = vi.fn();
+    const literal = vi.fn();
+    const bar = new CommandSet(defineCommands({ "bar.open": open }));
+    const set = new CommandSet(defineCommands({ "pane.literalCtrlK": literal }), {
+      leader: DEFAULT_LEADER,
+    });
+    const target = terminal();
+    expect(pressOn(set, target, "a", { ctrlKey: true })).toBe(true);
+    const e = key("k", { ctrlKey: true });
+    Object.defineProperty(e, "target", { value: target });
+    expect(set.handle(e)).toBe(true);
+    expect(literal).toHaveBeenCalledTimes(1);
+    // The leader's set consumed the key, so the bar's set never sees it.
+    expect(open).not.toHaveBeenCalled();
+    expect(bar.handle(e)).toBe(true); // sanity: it would have opened otherwise
+    expect(open).toHaveBeenCalledTimes(1);
+  });
+
+  it("binds the escape hatch behind the default leader", () => {
+    const spec = COMMAND_SPECS.find((s) => s.id === "pane.literalCtrlK");
+    expect(spec?.keys).toEqual([`${DEFAULT_LEADER} ctrl-k`]);
+  });
+});

web/src/commands.ts

@@ -0,0 +1,408 @@
+// The web client's command registry (#148). One entry per command — a stable
+// id, a plain-language label, the key chord it answers to, and a `run()` — so
+// there is exactly one list of what the client can do. The `?` overlay renders
+// from it (`help.ts`), and every keybinding is dispatched through it; a command
+// added here is bound and documented in the same edit.
+//
+// Keys are canonical strings, the same spelling the TUI's `InputKey::canonical`
+// produces (`ctrl-shift-h`, `enter`, `esc`, `n`, `N`) and chords are those
+// joined by a space (`ctrl-a ctrl-k`). Matching the TUI's spelling is what lets
+// docs/COMMAND-BAR.md describe one key model for both clients.
+
+/** Where a command's keys are listened for. `global` is the window, `list` the
+ *  sidebar's session tree, `pane` the attached terminal, `overlay` the help
+ *  dialog while it is up. */
+export type CommandScope = "global" | "list" | "pane" | "overlay";
+
+export interface CommandSpec {
+  /** Stable identifier. Never rendered; safe to bind config and tests to. */
+  id: string;
+  /** Plain-language label — what the `?` overlay and (later) the command bar
+   *  show. */
+  label: string;
+  /** Help-overlay section. Groups render in the order they first appear here. */
+  group: string;
+  /** Canonical chords that run it. The first is the one shown to the operator;
+   *  the rest are aliases (`j` and `down`). */
+  keys: string[];
+  scope: CommandScope;
+}
+
+export interface Command extends CommandSpec {
+  run: () => void;
+}
+
+/** Default leader, mirroring the TUI's `[tui].leader`. `ctrl-a` is select-all
+ *  in a browser, so a set that owns the leader `preventDefault`s it. */
+export const DEFAULT_LEADER = "ctrl-a";
+
+/** Every command the web client has. The single list this issue exists to
+ *  create: labels, chords and grouping live here and nowhere else. */
+export const COMMAND_SPECS: readonly CommandSpec[] = [
+  {
+    id: "spawn.open",
+    label: "Open the spawn form",
+    group: "Sessions",
+    keys: ["n"],
+    scope: "global",
+  },
+  {
+    id: "spawn.fastForward",
+    label: "Spawn a session with every default resolved",
+    group: "Sessions",
+    keys: ["N"],
+    scope: "global",
+  },
+  {
+    id: "bar.open",
+    label: "Open the command bar",
+    group: "Sessions",
+    keys: ["ctrl-k"],
+    scope: "global",
+  },
+  {
+    id: "pane.literalCtrlK",
+    label: "Send a literal Ctrl-K to the pane",
+    group: "Pane",
+    keys: [`${DEFAULT_LEADER} ctrl-k`],
+    scope: "global",
+  },
+  {
+    id: "focus.toggle",
+    label: "Move the keyboard between the session list and the pane",
+    group: "Session list",
+    keys: ["ctrl-shift-h"],
+    scope: "global",
+  },
+  {
+    id: "list.next",
+    label: "Highlight the next session",
+    group: "Session list",
+    keys: ["j", "down"],
+    scope: "list",
+  },
+  {
+    id: "list.prev",
+    label: "Highlight the previous session",
+    group: "Session list",
+    keys: ["k", "up"],
+    scope: "list",
+  },
+  {
+    id: "list.activate",
+    label: "Open the highlighted session, or expand a folder",
+    group: "Session list",
+    keys: ["enter"],
+    scope: "list",
+  },
+  {
+    id: "list.toggleFolder",
+    label: "Collapse or expand the highlighted folder",
+    group: "Session list",
+    keys: ["c"],
+    scope: "list",
+  },
+  {
+    id: "list.rename",
+    label: "Rename the highlighted session",
+    group: "Session list",
+    keys: ["r"],
+    scope: "list",
+  },
+  {
+    id: "list.kill",
+    label: "Kill the highlighted session",
+    group: "Session list",
+    keys: ["x"],
+    scope: "list",
+  },
+  {
+    id: "list.focusPane",
+    label: "Send the keyboard to the pane",
+    group: "Session list",
+    keys: ["tab"],
+    scope: "list",
+  },
+  {
+    id: "pane.focusList",
+    label: "Hand the keyboard back to the session list, from the pane",
+    group: "Session list",
+    keys: ["esc"],
+    scope: "pane",
+  },
+  {
+    id: "help.toggle",
+    label: "Show or hide this help",
+    group: "Help",
+    keys: ["?"],
+    scope: "global",
+  },
+  {
+    id: "help.close",
+    label: "Close the help overlay or an open menu",
+    group: "Help",
+    keys: ["esc"],
+    scope: "overlay",
+  },
+  {
+    id: "debug.toggleHud",
+    label: "Toggle the debug HUD",
+    group: "Debug",
+    keys: ["ctrl-shift-d"],
+    scope: "global",
+  },
+];
+
+const SPEC_BY_ID = new Map(COMMAND_SPECS.map((s) => [s.id, s]));
+
+/** Attach handlers to specs, by id. Throws on an unknown id, so a typo is a
+ *  test failure rather than a key that silently does nothing. */
+export function defineCommands(handlers: Record<string, () => void>): Command[] {
+  return Object.entries(handlers).map(([id, run]) => {
+    const spec = SPEC_BY_ID.get(id);
+    if (!spec) throw new Error(`unknown command id: ${id}`);
+    return { ...spec, run };
+  });
+}
+
+// ---- what the help overlay renders ----
+
+const published = new Map<string, Command>();
+
+/** Record commands as bound. Re-registering an id replaces it, so a second
+ *  sidebar (tests, hot reload) doesn't duplicate rows in the overlay. */
+export function publishCommands(cmds: Command[]): void {
+  for (const c of cmds) published.set(c.id, c);
+}
+
+/** Every bound command, in `COMMAND_SPECS` order. */
+export function publishedCommands(): Command[] {
+  return COMMAND_SPECS.map((s) => published.get(s.id)).filter((c): c is Command => c !== undefined);
+}
+
+// ---- key canonicalisation ----
+
+const NAMED: Record<string, string> = {
+  Escape: "esc",
+  Enter: "enter",
+  Tab: "tab",
+  Backspace: "backspace",
+  ArrowUp: "up",
+  ArrowDown: "down",
+  ArrowLeft: "left",
+  ArrowRight: "right",
+  Home: "home",
+  End: "end",
+  PageUp: "pageup",
+  PageDown: "pagedown",
+  Delete: "delete",
+  " ": "space",
+};
+
+/** The canonical string for one keydown. Mirrors the TUI's
+ *  `InputKey::canonical`: modifier prefixes in ctrl/alt/shift order, then the
+ *  key. A shifted character already spells itself (`N`, `?`), so `shift-` is
+ *  only written when another modifier is present and the char was folded to
+ *  lower case. */
+export function canonicalizeKey(e: KeyboardEvent): string | null {
+  if (!e.key) return null;
+  // Modifier keys pressed alone are never a binding.
+  if (e.key === "Control" || e.key === "Alt" || e.key === "Shift" || e.key === "Meta") return null;
+  const named = NAMED[e.key];
+  if (named === "tab" && e.shiftKey) return "backtab";
+  let out = "";
+  if (e.ctrlKey) out += "ctrl-";
+  if (e.altKey) out += "alt-";
+  if (e.metaKey) out += "meta-";
+  if (named) {
+    if (e.shiftKey) out += "shift-";
+    return out + named;
+  }
+  if (e.key.length === 1) {
+    if (out === "") return e.key;
+    if (e.shiftKey) out += "shift-";
+    return out + e.key.toLowerCase();
+  }
+  if (e.shiftKey) out += "shift-";
+  return out + e.key.toLowerCase();
+}
+
+const MOD_PREFIX = /^(ctrl|alt|meta|shift)-/;
+
+/** True when a chord carries a modifier or more than one key. Plain single-key
+ *  chords are the ones that stay deaf inside form fields. */
+function isChorded(chord: string): boolean {
+  return chord.includes(" ") || MOD_PREFIX.test(chord);
+}
+
+/** True when the event target swallows plain keystrokes — a form field, or the
+ *  hidden textarea xterm types into. Every plain single-key binding is deaf in
+ *  the same places. */
+export function isTypingTarget(target: EventTarget | null): boolean {
+  const el = target as HTMLElement | null;
+  if (!el || typeof el.tagName !== "string") return false;
+  return (
+    el.tagName === "INPUT" ||
+    el.tagName === "TEXTAREA" ||
+    el.tagName === "SELECT" ||
+    el.isContentEditable
+  );
+}
+
+/** xterm's offscreen textarea. It is a typing target like any other, but it is
+ *  also where the leader has to work — a pane is exactly where the operator
+ *  needs the escape hatch (docs/COMMAND-BAR.md). */
+export function isTerminalTextarea(target: EventTarget | null): boolean {
+  const el = target as HTMLElement | null;
+  return !!el && typeof el.className === "string" && el.classList?.contains("xterm-helper-textarea");
+}
+
+/** True where the command bar's own keys must stay out of the way: a real form
+ *  field, and not the pane. `ctrl-k` is intercepted ahead of xterm
+ *  (docs/COMMAND-BAR.md, "Opening"), so a focused terminal opens the bar, while
+ *  the spawn form's inputs keep their own Ctrl-K. */
+export function isBarTypingTarget(target: EventTarget | null): boolean {
+  return isTypingTarget(target) && !isTerminalTextarea(target);
+}
+
+// ---- display ----
+
+const CAPS: Record<string, string> = {
+  ctrl: "Ctrl",
+  alt: "Alt",
+  meta: "Meta",
+  shift: "Shift",
+  esc: "Esc",
+  enter: "Enter",
+  tab: "Tab",
+  backtab: "Shift Tab",
+  backspace: "Backspace",
+  up: "Up",
+  down: "Down",
+  left: "Left",
+  right: "Right",
+  home: "Home",
+  end: "End",
+  pageup: "PgUp",
+  pagedown: "PgDn",
+  delete: "Del",
+  space: "Space",
+};
+
+/** Keycaps for a chord, left to right: `ctrl-shift-h` → Ctrl, Shift, H. A
+ *  multi-key chord separates its keys with a `then` cap. */
+export function keyCaps(chord: string): string[] {
+  const caps: string[] = [];
+  for (const [i, key] of chord.split(" ").entries()) {
+    if (i > 0) caps.push("then");
+    const parts = key.split("-");
+    // A bare `-` key splits into two empties; treat it as the key itself.
+    if (parts.every((p) => p === "")) {
+      caps.push("-");
+      continue;
+    }
+    const last = parts.pop() as string;
+    const mods = parts.filter((p) => p !== "");
+    for (const m of mods) caps.push(CAPS[m] ?? m);
+    caps.push(CAPS[last] ?? (mods.length > 0 && last.length === 1 ? last.toUpperCase() : last));
+  }
+  return caps;
+}
+
+// ---- dispatch ----
+
+/** How long a partial chord waits for its next key — the TUI's
+ *  `chord_timeout_ms` default. */
+export const DEFAULT_CHORD_TIMEOUT_MS = 1000;
+
+export interface CommandSetOptions {
+  /** Canonical leader key. A set given one holds every leader press as a
+   *  pending chord, whether or not anything is bound behind it yet. */
+  leader?: string | null;
+  chordTimeoutMs?: number;
+  /** Call `preventDefault()` on a handled key. Off for the terminal's own key
+   *  handler, which swallows by returning `false` to xterm instead. */
+  preventDefault?: boolean;
+  /** Clock, for tests. */
+  now?: () => number;
+}
+
+/** A group of commands listening on one surface. Resolves a keydown to a
+ *  command the way the TUI's `ChordState` does: hold while the sequence is a
+ *  strict prefix of some binding, otherwise resolve and dispatch. */
+export class CommandSet {
+  private readonly byChord = new Map<string, Command>();
+  private readonly leader: string | null;
+  private readonly timeout: number;
+  private readonly preventDefault: boolean;
+  private readonly now: () => number;
+  private held: string[] = [];
+  private lastPress = 0;
+
+  constructor(
+    readonly commands: Command[],
+    opts: CommandSetOptions = {},
+  ) {
+    for (const c of commands) for (const k of c.keys) this.byChord.set(k, c);
+    this.leader = opts.leader ?? null;
+    this.timeout = opts.chordTimeoutMs ?? DEFAULT_CHORD_TIMEOUT_MS;
+    this.preventDefault = opts.preventDefault ?? true;
+    this.now = opts.now ?? (() => Date.now());
+    publishCommands(commands);
+  }
+
+  /** Whether any binding starts with `candidate` and continues. */
+  private isPrefix(candidate: string): boolean {
+    const marker = `${candidate} `;
+    for (const chord of this.byChord.keys()) if (chord.startsWith(marker)) return true;
+    return false;
+  }
+
+  /** Feed one keydown. Returns true when the key was consumed — dispatched, or
+   *  held as a partial chord. */
+  handle(e: KeyboardEvent): boolean {
+    const key = canonicalizeKey(e);
+    if (key === null) return false;
+    if (this.held.length > 0 && this.now() - this.lastPress > this.timeout) this.held = [];
+    const candidate = this.held.length > 0 ? `${this.held.join(" ")} ${key}` : key;
+    this.lastPress = this.now();
+
+    // The leader is a prefix by construction, so it stops being select-all
+    // before anything is bound behind it (#149 binds the first chord).
+    if (this.leader !== null && this.held.length === 0 && key === this.leader) {
+      if (isTypingTarget(e.target) && !isTerminalTextarea(e.target)) return false;
+      this.held = [key];
+      if (this.preventDefault) e.preventDefault();
+      return true;
+    }
+
+    if (this.isPrefix(candidate)) {
+      this.held.push(key);
+      if (this.preventDefault) e.preventDefault();
+      return true;
+    }
+
+    const wasChord = this.held.length > 0;
+    this.held = [];
+    const cmd = this.byChord.get(candidate);
+    if (!cmd) {
+      // A chord that resolved to nothing is still consumed: the leader took
+      // the key, so it must not also fall through to a plain binding.
+      return wasChord;
+    }
+    // Plain single-key bindings are deaf where typing happens; chorded ones are
+    // not, and neither are the pane's and the overlay's, which are only fed
+    // from the surface that owns them.
+    if (
+      !isChorded(candidate) &&
+      cmd.scope !== "pane" &&
+      cmd.scope !== "overlay" &&
+      isTypingTarget(e.target)
+    ) {
+      return false;
+    }
+    if (this.preventDefault) e.preventDefault();
+    cmd.run();
+    return true;
+  }
+}

web/src/connections.test.ts

@@ -3,6 +3,23 @@ import { afterEach, describe, expect, it, vi } from "vitest";
 
 import { ConnectionPool } from "./connections.js";
 
+// The pane's own bytes-out path, stubbed: the escape hatch only needs to know
+// the pool reaches the focused connection with them.
+const sent: { id: string; data: string }[] = [];
+vi.mock("./attach.js", () => ({
+  createAttachConnection: (id: string) => ({
+    sessionId: id,
+    el: document.createElement("div"),
+    onMount() {},
+    onUnmount() {},
+    focusTerminal() {},
+    sendInput(data: string) {
+      sent.push({ id, data });
+    },
+    dispose() {},
+  }),
+}));
+
 afterEach(() => {
   vi.unstubAllGlobals();
 });
@@ -85,3 +102,26 @@ describe("ConnectionPool.setFocus", () => {
     await Promise.resolve();
   });
 });
+
+describe("ConnectionPool.sendToFocused", () => {
+  it("types the bytes into the focused session's PTY", () => {
+    mockFetch();
+    sent.length = 0;
+    const pool = new ConnectionPool();
+    const pane = document.createElement("div");
+    pool.mount(A, pane);
+    pool.setFocus(A);
+
+    expect(pool.sendToFocused("\x0b")).toBe(true);
+    expect(sent).toEqual([{ id: A, data: "\x0b" }]);
+  });
+
+  it("is a no-op with nothing focused", () => {
+    mockFetch();
+    sent.length = 0;
+    const pool = new ConnectionPool();
+
+    expect(pool.sendToFocused("\x0b")).toBe(false);
+    expect(sent).toEqual([]);
+  });
+});

web/src/connections.ts

@@ -159,6 +159,18 @@ export class ConnectionPool {
     this.cache.get(this.focusedId)?.focusTerminal();
   }
 
+  /** Type raw bytes into the focused session's PTY. Returns false when there is
+   *  nothing focused, or its connection is gone — the leader's literal Ctrl-K
+   *  is a no-op over the welcome pane rather than an error
+   *  (docs/COMMAND-BAR.md). */
+  sendToFocused(data: string): boolean {
+    if (this.focusedId === null) return false;
+    const conn = this.cache.get(this.focusedId);
+    if (!conn) return false;
+    conn.sendInput(data);
+    return true;
+  }
+
   /** Fully disconnect + forget a session. */
   close(id: Uuid): void {
     const conn = this.cache.get(id);

web/src/debug.ts

@@ -2,6 +2,8 @@
 // survives reloads, flipped by a keybind (Ctrl+Shift+D), and force-enabled by
 // `?hud` in dev. A `maestro-hud-toggle` event lets the HUD re-render on change.
 
+import { CommandSet, defineCommands } from "./commands.js";
+
 const STORAGE_KEY = "maestro:hud";
 export const HUD_TOGGLE_EVENT = "maestro-hud-toggle";
 
@@ -31,12 +33,9 @@ export function toggleHud(): void {
   setHudEnabled(!isHudEnabled());
 }
 
+const hudKeys = new CommandSet(defineCommands({ "debug.toggleHud": () => toggleHud() }));
+
 /** Global keybind: Ctrl+Shift+D toggles the debug HUD. */
 export function installHudKeybind(): void {
-  window.addEventListener("keydown", (e) => {
-    if (e.ctrlKey && e.shiftKey && (e.key === "D" || e.key === "d")) {
-      e.preventDefault();
-      toggleHud();
-    }
-  });
+  window.addEventListener("keydown", (e) => hudKeys.handle(e));
 }

web/src/help.test.ts

@@ -1,14 +1,8 @@
 // @vitest-environment happy-dom
 import { afterEach, beforeEach, describe, expect, it } from "vitest";
 
-import {
-  SHORTCUTS,
-  closeHelp,
-  installHelpKeybind,
-  isHelpOpen,
-  isTypingTarget,
-  openHelp,
-} from "./help.js";
+import { keyCaps, publishedCommands } from "./commands.js";
+import { closeHelp, groupedCommands, installHelpKeybind, isHelpOpen, openHelp } from "./help.js";
 
 beforeEach(() => {
   installHelpKeybind();
@@ -30,14 +24,24 @@ function rows(): string[] {
 }
 
 describe("help overlay", () => {
-  it("renders every registered shortcut, grouped", () => {
+  it("renders exactly the commands the registry has bound, grouped", () => {
     openHelp();
-    const groups = [...document.querySelectorAll(".help-group-title")].map((h) => h.textContent);
-    expect(groups).toEqual(SHORTCUTS.map((g) => g.title));
-    expect(rows()).toEqual(SHORTCUTS.flatMap((g) => g.items.map((s) => s.keys.join(" "))));
-    expect(document.querySelectorAll(".help-desc")).toHaveLength(
-      SHORTCUTS.reduce((n, g) => n + g.items.length, 0),
+    const groups = groupedCommands();
+    expect([...document.querySelectorAll(".help-group-title")].map((h) => h.textContent)).toEqual(
+      groups.map((g) => g.title),
     );
+    expect(rows()).toEqual(
+      groups.flatMap((g) => g.items.map((c) => keyCaps(c.keys[0]).join(" "))),
+    );
+    expect([...document.querySelectorAll(".help-desc")].map((d) => d.textContent)).toEqual(
+      groups.flatMap((g) => g.items.map((c) => c.label)),
+    );
+  });
+
+  it("names each row by its command id, so a row can't drift from its command", () => {
+    openHelp();
+    expect([...document.querySelectorAll<HTMLElement>(".help-row")].map((r) => r.dataset.commandId))
+      .toEqual(publishedCommands().map((c) => c.id));
   });
 
   it("opens on ? and closes on a second ?", () => {
@@ -94,19 +98,3 @@ describe("help overlay", () => {
     expect(document.querySelectorAll(".help-overlay")).toHaveLength(1);
   });
 });
-
-describe("isTypingTarget", () => {
-  it("is true for form fields and editable nodes, false otherwise", () => {
-    const el = (html: string) => {
-      const d = document.createElement("div");
-      d.innerHTML = html;
-      return d.firstElementChild as HTMLElement;
-    };
-    expect(isTypingTarget(el("<input>"))).toBe(true);
-    expect(isTypingTarget(el("<textarea></textarea>"))).toBe(true);
-    expect(isTypingTarget(el("<select></select>"))).toBe(true);
-    expect(isTypingTarget(el('<div contenteditable="true"></div>'))).toBe(true);
-    expect(isTypingTarget(el("<button></button>"))).toBe(false);
-    expect(isTypingTarget(null)).toBe(false);
-  });
-});

web/src/help.ts

@@ -1,69 +1,15 @@
 /** Keyboard-shortcut overlay (`?`), the web counterpart of the TUI's help
- *  overlay. One registry drives both the rendering and what we claim is bound,
- *  so a binding added to `main.ts` without an entry here reads as missing. */
+ *  overlay. It renders the command registry (`commands.ts`) — the same list
+ *  that dispatches the keys — so a binding can never be documented as one
+ *  thing and do another. */
 
-export interface Shortcut {
-  /** Keycaps, rendered left to right as separate <kbd>. */
-  keys: string[];
-  description: string;
-}
-
-export interface ShortcutGroup {
-  title: string;
-  items: Shortcut[];
-}
-
-export const SHORTCUTS: ShortcutGroup[] = [
-  {
-    title: "Sessions",
-    items: [
-      { keys: ["n"], description: "Open the spawn form" },
-      { keys: ["N"], description: "Spawn a session with every default resolved" },
-    ],
-  },
-  {
-    title: "Session list",
-    items: [
-      {
-        keys: ["Ctrl", "Shift", "H"],
-        description: "Move the keyboard between the session list and the pane",
-      },
-      { keys: ["j"], description: "Highlight the next session" },
-      { keys: ["k"], description: "Highlight the previous session" },
-      { keys: ["Enter"], description: "Open the highlighted session, or expand a folder" },
-      { keys: ["c"], description: "Collapse or expand the highlighted folder" },
-      { keys: ["r"], description: "Rename the highlighted session" },
-      { keys: ["x"], description: "Kill the highlighted session" },
-      { keys: ["Tab"], description: "Send the keyboard to the pane" },
-      { keys: ["Esc"], description: "Hand the keyboard back to the session list, from the pane" },
-    ],
-  },
-  {
-    title: "Help",
-    items: [
-      { keys: ["?"], description: "Show or hide this help" },
-      { keys: ["Esc"], description: "Close the help overlay or an open menu" },
-    ],
-  },
-  {
-    title: "Debug",
-    items: [{ keys: ["Ctrl", "Shift", "D"], description: "Toggle the debug HUD" }],
-  },
-];
-
-/** True when the event target swallows plain keystrokes — a form field, or the
- *  hidden textarea xterm types into. Shared with `main.ts` so every global
- *  single-key binding is deaf in the same places. */
-export function isTypingTarget(target: EventTarget | null): boolean {
-  const el = target as HTMLElement | null;
-  if (!el || typeof el.tagName !== "string") return false;
-  return (
-    el.tagName === "INPUT" ||
-    el.tagName === "TEXTAREA" ||
-    el.tagName === "SELECT" ||
-    el.isContentEditable
-  );
-}
+import {
+  CommandSet,
+  defineCommands,
+  keyCaps,
+  publishedCommands,
+  type Command,
+} from "./commands.js";
 
 let open: { el: HTMLElement; dispose: () => void } | null = null;
 
@@ -108,7 +54,7 @@ export function openHelp(): HTMLElement {
   head.append(title, close);
   panel.appendChild(head);
 
-  for (const group of SHORTCUTS) {
+  for (const group of groupedCommands()) {
     const section = document.createElement("section");
     section.className = "help-group";
     const heading = document.createElement("h3");
@@ -116,19 +62,20 @@ export function openHelp(): HTMLElement {
     heading.textContent = group.title;
     const list = document.createElement("dl");
     list.className = "help-list";
-    for (const item of group.items) {
+    for (const cmd of group.items) {
       const row = document.createElement("div");
       row.className = "help-row";
+      row.dataset.commandId = cmd.id;
       const keys = document.createElement("dt");
       keys.className = "help-keys";
-      for (const key of item.keys) {
+      for (const key of keyCaps(cmd.keys[0])) {
         const cap = document.createElement("kbd");
         cap.textContent = key;
         keys.appendChild(cap);
       }
       const desc = document.createElement("dd");
       desc.className = "help-desc";
-      desc.textContent = item.description;
+      desc.textContent = cmd.label;
       row.append(keys, desc);
       list.appendChild(row);
     }
@@ -153,6 +100,26 @@ export function openHelp(): HTMLElement {
   return el;
 }
 
+/** The registry's commands, in registry order, bucketed into the help
+ *  overlay's sections. Groups appear in the order their first command does. */
+export function groupedCommands(): { title: string; items: Command[] }[] {
+  const groups: { title: string; items: Command[] }[] = [];
+  for (const cmd of publishedCommands()) {
+    let group = groups.find((g) => g.title === cmd.group);
+    if (!group) {
+      group = { title: cmd.group, items: [] };
+      groups.push(group);
+    }
+    group.items.push(cmd);
+  }
+  return groups;
+}
+
+// The overlay's own two commands. `help.close` is `overlay`-scoped: it is only
+// fed keys while the dialog is up.
+const helpKeys = new CommandSet(defineCommands({ "help.toggle": () => toggleHelp() }));
+const overlayKeys = new CommandSet(defineCommands({ "help.close": () => closeHelp() }));
+
 let installed = false;
 
 /** Global keybind: `?` toggles the overlay, Escape closes it. Idempotent, so a
@@ -161,16 +128,7 @@ export function installHelpKeybind(): void {
   if (installed) return;
   installed = true;
   window.addEventListener("keydown", (e) => {
-    if (e.key === "Escape" && open) {
-      e.preventDefault();
-      closeHelp();
-      return;
-    }
-    // Shift is how `?` is typed on most layouts; the others would be a
-    // different binding entirely.
-    if (e.key !== "?" || e.ctrlKey || e.altKey || e.metaKey) return;
-    if (isTypingTarget(e.target)) return;
-    e.preventDefault();
-    toggleHelp();
+    if (open && overlayKeys.handle(e)) return;
+    helpKeys.handle(e);
   });
 }

web/src/kit.ts

@@ -129,6 +129,7 @@ export function renderKit(): HTMLElement {
       "--muted",
       "--faint",
       "--accent",
+      "--preview",
       "--danger",
       "--warn",
     ];

web/src/main.ts

@@ -6,7 +6,9 @@ import { renderSidebar } from "./catalog.js";
 import { ConnectionPool } from "./connections.js";
 import { installDrawer, installDrawerSwipe, requestToggleDrawer } from "./drawer.js";
 import { installHudKeybind } from "./debug.js";
-import { installHelpKeybind, isHelpOpen, isTypingTarget } from "./help.js";
+import { installHelpKeybind, isHelpOpen } from "./help.js";
+import { CommandSet, DEFAULT_LEADER, defineCommands, isBarTypingTarget } from "./commands.js";
+import { isCommandBarOpen, openCommandBar, SPAWN_DIRECTORY_EVENT } from "./commandBar.js";
 import { DaemonLink } from "./daemonLink.js";
 import { CatalogStore } from "./events.js";
 import { installRestartOverlay } from "./restartOverlay.js";
@@ -15,6 +17,7 @@ import {
   createSession,
   fetchNames,
   getDaemonInfo,
+  gitRoot,
   projects as fetchProjects,
 } from "./api.js";
 import {
@@ -29,6 +32,7 @@ import { mountHud, type Hud } from "./hud.js";
 import { emptyLayout, type Layout, openSessions } from "./layout.js";
 import { createMultiView, type MultiView } from "./multiview.js";
 import { loadLayout, saveLayout } from "./persistence.js";
+import { createPreviewSchedule } from "./previewSchedule.js";
 import {
   FOCUS_PANE_EVENT,
   FOCUS_SIDEBAR_EVENT,
@@ -78,6 +82,15 @@ async function bootApp(): Promise<void> {
 
 const store = new CatalogStore();
 
+// The daemon's home dir, for the command bar's `~/…` directory abbreviation.
+// Absolute paths are a fine fallback until it lands.
+let homeDir: string | undefined;
+void getDaemonInfo()
+  .then((info) => (homeDir = info.home_dir))
+  .catch(() => {
+    /* absolute paths are a fine fallback */
+  });
+
 // The daemon's identity and liveness: names the release in the sidebar's status
 // dot, and blocks the UI behind the restart overlay while the daemon is away
 // (docs/RESTART.md). The events socket is the trigger — it dies first.
@@ -105,20 +118,14 @@ shellEl.dataset.route = "catalog";
 // point `mv` is assigned.
 let mv: MultiView;
 
-// Preview timing (docs/PREVIEW.md): a keyboard step shows almost at once; a
-// mouse sweep waits long enough that rows crossed on the way somewhere else
-// never flash up. The same delay applies to clearing, so the gap between two
-// rows doesn't blink the previous view back.
-const PREVIEW_DELAY = { key: 60, hover: 150 } as const;
-let previewTimer: number | undefined;
-function schedulePreview(sessionId: string | null, source: "key" | "hover"): void {
-  clearTimeout(previewTimer);
-  previewTimer = window.setTimeout(() => {
-    ensureMultiView();
-    mv?.previewSession(sessionId);
-    updateShellRoute();
-  }, PREVIEW_DELAY[source]);
-}
+// Preview timing (docs/PREVIEW.md): the first move shows at once, and a burst
+// — j held down, or the pointer sweeping the whole list — is coalesced so it
+// costs a couple of pane mounts instead of one per row walked.
+const schedulePreview = createPreviewSchedule((sessionId) => {
+  ensureMultiView();
+  mv?.previewSession(sessionId);
+  updateShellRoute();
+});
 
 const sidebar = renderSidebar(store, {
   onLeafDrag: (id, e) => mv?.beginSessionDrag(id, e),
@@ -331,6 +338,16 @@ function mountSpawned(session: Session, placement?: { newTab?: boolean }): void
 // a new branch named after that name. Anything unresolvable (no projects
 // known yet, no command, no generated name) opens the form pre-filled with
 // what did resolve instead.
+async function spawnPresets(): Promise<SpawnPreset[]> {
+  try {
+    const info = await getDaemonInfo();
+    if (info.presets?.length) return info.presets;
+  } catch {
+    /* keep fallbacks */
+  }
+  return FALLBACK_PRESETS;
+}
+
 async function requestFastForward(): Promise<void> {
   const [discovered, name] = await Promise.all([
     fetchProjects().catch(() => [] as Project[]),
@@ -338,13 +355,7 @@ async function requestFastForward(): Promise<void> {
       .then((batch) => batch.names[0])
       .catch(() => undefined),
   ]);
-  let presets: SpawnPreset[] = FALLBACK_PRESETS;
-  try {
-    const info = await getDaemonInfo();
-    if (info.presets?.length) presets = info.presets;
-  } catch {
-    /* keep fallbacks */
-  }
+  const presets = await spawnPresets();
   const resolved = resolveFastForward(discovered, presets, name, focusedProjectCwd());
   const req = buildFastForwardRequest(resolved);
   if (req) {
@@ -366,38 +377,122 @@ async function requestFastForward(): Promise<void> {
   });
 }
 
-// Keyboard pair (#67): `n` opens the spawn modal, `N` fast-forwards a spawn.
-// Ignored while typing anywhere (form fields, the terminal's hidden
-// textarea, search) so an attached session's keys are never hijacked.
-document.addEventListener("keydown", (e) => {
-  if (e.ctrlKey || e.altKey || e.metaKey) return;
-  if (isTypingTarget(e.target)) return;
-  // The help overlay owns the keyboard while it is up.
-  if (isHelpOpen()) return;
-  if (e.key === "n") {
-    e.preventDefault();
-    requestOpenSpawn();
-  } else if (e.key === "N") {
-    e.preventDefault();
-    void requestFastForward();
+// Enter on a `~` row in the command bar (docs/COMMAND-BAR.md): the same
+// fast-forward spawn, aimed at the chosen directory instead of the most recent
+// project. A directory the project scan never saw stands in as its own project;
+// one outside any repo spawns without a worktree, since there is no repo to cut
+// a branch from. Anything still unresolved opens the pre-filled form.
+async function requestSpawnInDirectory(path: string): Promise<void> {
+  const [discovered, name] = await Promise.all([
+    fetchProjects().catch(() => [] as Project[]),
+    fetchNames(1)
+      .then((batch) => batch.names[0])
+      .catch(() => undefined),
+  ]);
+  const presets = await spawnPresets();
+  const known = discovered.find((p) => p.path === path);
+  const project: Project = known ?? { path, name: path.split("/").filter(Boolean).pop() ?? path };
+  const resolved = resolveFastForward([project], presets, name, path);
+  const req = buildFastForwardRequest(resolved);
+  if (req) {
+    const inRepo =
+      known !== undefined ||
+      (await gitRoot(path)
+        .then((r) => !!r.root)
+        .catch(() => false));
+    if (!inRepo) delete req.worktree;
+    try {
+      mountSpawned(await createSession(req));
+      return;
+    } catch {
+      // A failed POST degrades to the pre-filled form, never a dead row.
+    }
   }
+  openSpawnModal({
+    seed: fastForwardSeed(resolved),
+    onSuccess: (session) => mountSpawned(session),
+  });
+}
+
+document.addEventListener(SPAWN_DIRECTORY_EVENT, (ev) => {
+  void requestSpawnInDirectory((ev as CustomEvent<string>).detail);
 });
 
+// The global half of the command registry (#148). Two sets, because they
+// differ in one thing: the help overlay owns the keyboard while it is up, so
+// the plain keys go deaf behind it while the focus chord does not — an
+// attached terminal must never be able to trap the focus keys.
+//
+// `n` opens the spawn modal, `N` fast-forwards a spawn (#67). Both are plain
+// keys, so `isTypingTarget` inside the set keeps them out of form fields and the terminal's
+// hidden textarea.
+const spawnKeys = new CommandSet(
+  defineCommands({
+    "spawn.open": () => requestOpenSpawn(),
+    "spawn.fastForward": () => void requestFastForward(),
+  }),
+);
+
 // Ctrl+Shift+H moves the keyboard between the session list and the pane, the
 // web counterpart of the TUI's `ctrl-w h`. It has to be a chord: an attached
 // terminal owns every plain keystroke, so nothing unmodified could ever get
 // the focus back out of it.
-window.addEventListener("keydown", (e) => {
-  if (!e.ctrlKey || !e.shiftKey || e.altKey || e.metaKey) return;
-  if (e.key !== "H" && e.key !== "h") return;
-  e.preventDefault();
-  if (sidebar.hasListFocus()) {
-    pool.focusTerminal();
-  } else {
-    drawer.open(); // no-op on desktop; on mobile the list is off-canvas
-    sidebar.focusList();
-  }
-});
+//
+// This set also owns the leader (`ctrl-a`, the TUI's default): it holds the
+// key as a partial chord and takes select-all off it, so the escape hatch
+// docs/COMMAND-BAR.md describes has somewhere to land (#149).
+const focusKeys = new CommandSet(
+  defineCommands({
+    "focus.toggle": () => {
+      if (sidebar.hasListFocus()) {
+        pool.focusTerminal();
+      } else {
+        drawer.open(); // no-op on desktop; on mobile the list is off-canvas
+        sidebar.focusList();
+      }
+    },
+    // The escape hatch: binding ctrl-k takes readline's kill-to-end-of-line
+    // away from every pane, and leader ctrl-k gives it back as the literal
+    // 0x0B byte (docs/COMMAND-BAR.md). It resolves in this set, ahead of the
+    // bar's, so the chord never opens the bar.
+    "pane.literalCtrlK": () => pool.sendToFocused("\x0b"),
+  }),
+  { leader: DEFAULT_LEADER },
+);
+
+// Ctrl+K opens the command bar (docs/COMMAND-BAR.md). It is a registry command
+// like any other, so the `?` overlay lists it without a second list.
+const barKeys = new CommandSet(
+  defineCommands({
+    "bar.open": () => {
+      // Opening while a session is previewed discards the preview first, like
+      // any other real change (docs/PREVIEW.md): the bar is not previewed into.
+      schedulePreview.cancel();
+      mv?.previewSession(null);
+      openCommandBar({ sessions: [...store.snapshot().sessions.values()], homeDir });
+    },
+  }),
+);
+
+// Capture phase: an attached xterm swallows every keystroke it is given, so the
+// bar's binding has to be seen ahead of the terminal (docs/COMMAND-BAR.md).
+window.addEventListener(
+  "keydown",
+  (e) => {
+    // The bar owns the keyboard while it is up; its own input handles the keys.
+    if (isCommandBarOpen()) return;
+    if (focusKeys.handle(e)) return;
+    // The help overlay owns the keyboard while it is up.
+    if (isHelpOpen()) return;
+    // The pane's hidden textarea is not a typing target for the bar: ctrl-k is
+    // seen ahead of xterm and opens the bar (#152). A real form field — the
+    // spawn form's inputs — keeps its own Ctrl+K.
+    if (!isBarTypingTarget(e.target) && barKeys.handle(e)) return;
+    spawnKeys.handle(e);
+  },
+  true,
+);
+
 
 // Tab in the session list hands the keyboard to the pane; Escape in the pane
 // hands it back — the pair the TUI gets from `tab` and `esc`.
@@ -418,7 +513,7 @@ document.addEventListener(FOCUS_SIDEBAR_EVENT, () => {
  *  on `hashchange` alone — a split or drag can move focus without the hash
  *  changing, leaving a click back onto that session's row silently ignored. */
 function focusSession(sessionId: string): void {
-  clearTimeout(previewTimer);
+  schedulePreview.cancel();
   showMultiView();
   mv.openSession(sessionId);
   updateShellRoute();

web/src/matcher.test.ts

@@ -0,0 +1,201 @@
+import { describe, expect, it } from "vitest";
+
+import {
+  matchAndRank,
+  type CommandCandidate,
+  type DirectoryCandidate,
+  type MatchCandidate,
+  type MatchResult,
+  type SessionCandidate,
+} from "./matcher.js";
+
+function session(
+  name: string,
+  directory?: string,
+  command?: string,
+  tool?: string,
+): SessionCandidate {
+  return { kind: "session", fields: { name, directory, command, tool } };
+}
+
+function command(label: string): CommandCandidate {
+  return { kind: "command", fields: { label } };
+}
+
+function directory(path: string): DirectoryCandidate {
+  return { kind: "directory", fields: { path } };
+}
+
+function label(result: MatchResult): string {
+  switch (result.candidate.kind) {
+    case "session":
+      return `session:${result.candidate.fields.name}`;
+    case "command":
+      return `command:${result.candidate.fields.label}`;
+    case "directory":
+      return `directory:${result.candidate.fields.path}`;
+  }
+}
+
+function positions(result: MatchResult): number[] {
+  return result.ranges.flatMap(([start, end]) =>
+    Array.from({ length: end - start }, (_, offset) => start + offset),
+  );
+}
+
+function expectResults(
+  query: string,
+  candidates: MatchCandidate[],
+  expected: Array<[label: string, score: number, field?: string, positions?: number[]]>,
+): void {
+  const results = matchAndRank(query, candidates);
+
+  expect(results.map((result) => [label(result), result.score])).toEqual(
+    expected.map(([candidateLabel, score]) => [candidateLabel, score]),
+  );
+  expect(results.map((result) => result.field)).toEqual(
+    expected.map(([, , field]) => field),
+  );
+  expect(results.map(positions)).toEqual(expected.map(([, , , matched]) => matched ?? []));
+}
+
+describe("matchAndRank fixtures", () => {
+  it("F1: an empty query keeps input order", () => {
+    expectResults(
+      "",
+      [
+        session("kill", "~/dev/api", "bash"),
+        session("killer-app", "~/dev/killer-app", "claude --resume", "claude"),
+        command("Kill selected session"),
+      ],
+      [
+        ["session:kill", 0],
+        ["session:killer-app", 0],
+        ["command:Kill selected session", 0],
+      ],
+    );
+  });
+
+  it("F2: an exact session name beats a prefix and kind breaks a tie", () => {
+    expectResults(
+      "kill",
+      [
+        session("kill", "~/dev/api", "bash"),
+        session("killer-app", "~/dev/killer-app", "claude --resume", "claude"),
+        command("Kill selected session"),
+      ],
+      [
+        ["session:kill", 178, "name", [0, 1, 2, 3]],
+        ["session:killer-app", 146, "name", [0, 1, 2, 3]],
+        ["command:Kill selected session", 146, "label", [0, 1, 2, 3]],
+      ],
+    );
+  });
+
+  it("F3: path segment boundaries beat mid-segment matches", () => {
+    expectResults(
+      "foo",
+      [directory("~/dev/foobar"), directory("~/src/myfoo"), directory("~/foo")],
+      [
+        ["directory:~/foo", 78, "path", [2, 3, 4]],
+        ["directory:~/dev/foobar", 74, "path", [6, 7, 8]],
+        ["directory:~/src/myfoo", 56, "path", [8, 9, 10]],
+      ],
+    );
+  });
+
+  it("F4: a query matching nothing returns no candidates", () => {
+    expectResults("zzz", [session("kill", "~/dev/api", "bash"), command("Kill selected session")], []);
+  });
+
+  it("F5: the highest-scoring embedding can differ from the greedy embedding", () => {
+    expectResults(
+      "mtu",
+      [session("maestro-tui"), session("maestro-daemon"), session("mtui-scratch")],
+      [
+        ["session:mtui-scratch", 122, "name", [0, 1, 2]],
+        ["session:maestro-tui", 91, "name", [0, 8, 9]],
+      ],
+    );
+  });
+
+  it("F6: a name beats a weighted directory match", () => {
+    expectResults(
+      "api",
+      [session("api", "~/dev/web", "bash"), session("worker", "~/dev/api", "bash")],
+      [
+        ["session:api", 154, "name", [0, 1, 2]],
+        ["session:worker", 50, "directory", [6, 7, 8]],
+      ],
+    );
+  });
+
+  it("F7: matching is case-insensitive and field length breaks a tie", () => {
+    expectResults(
+      "api",
+      [session("API-Gateway"), session("apiary")],
+      [
+        ["session:apiary", 122, "name", [0, 1, 2]],
+        ["session:API-Gateway", 122, "name", [0, 1, 2]],
+      ],
+    );
+  });
+
+  it("F8: the exact tool field beats the command field", () => {
+    expectResults(
+      "claude",
+      [session("nameless", "~/dev/x", "claude --resume", "claude"), session("clay", "~/dev/y", "bash")],
+      [["session:nameless", 186, "tool", [0, 1, 2, 3, 4, 5]]],
+    );
+  });
+
+  it("F9: a separator earns a word-boundary bonus", () => {
+    expectResults(
+      "ws",
+      [session("websearch"), session("web-search")],
+      [
+        ["session:web-search", 71, "name", [0, 4]],
+        ["session:websearch", 56, "name", [0, 3]],
+      ],
+    );
+  });
+
+  it("F10: command labels rank by boundary and initial gap", () => {
+    expectResults(
+      "se",
+      [command("Kill selected session"), command("Create a session"), command("Show help")],
+      [
+        ["command:Show help", 53, "label", [0, 6]],
+        ["command:Kill selected session", 51, "label", [5, 6]],
+        ["command:Create a session", 47, "label", [9, 10]],
+      ],
+    );
+  });
+
+  it("F11: directory matches separate on their initial gap", () => {
+    expectResults(
+      "dev",
+      [
+        session("api", "~/dev/api", "bash"),
+        session("notes", "~/documents/dev-notes", "nvim"),
+        session("scratch", "~/srv/devops", "bash"),
+      ],
+      [
+        ["session:api", 54, "directory", [2, 3, 4]],
+        ["session:scratch", 50, "directory", [6, 7, 8]],
+        ["session:notes", 44, "directory", [12, 13, 14]],
+      ],
+    );
+  });
+
+  it("F12: an exact field beats a prefix", () => {
+    expectResults(
+      "quit",
+      [command("Quit Maestro"), command("Quit")],
+      [
+        ["command:Quit", 178, "label", [0, 1, 2, 3]],
+        ["command:Quit Maestro", 146, "label", [0, 1, 2, 3]],
+      ],
+    );
+  });
+});

web/src/matcher.ts

@@ -0,0 +1,224 @@
+export type CandidateKind = "session" | "command" | "directory";
+
+export interface SessionCandidate {
+  kind: "session";
+  fields: {
+    name: string;
+    directory?: string;
+    command?: string;
+    tool?: string;
+  };
+}
+
+export interface CommandCandidate {
+  kind: "command";
+  fields: { label: string };
+}
+
+export interface DirectoryCandidate {
+  kind: "directory";
+  fields: { path: string };
+}
+
+export type MatchCandidate = SessionCandidate | CommandCandidate | DirectoryCandidate;
+export type MatchFieldName = "name" | "directory" | "command" | "tool" | "label" | "path";
+export type MatchRange = readonly [start: number, end: number];
+
+export interface MatchResult<C extends MatchCandidate = MatchCandidate> {
+  candidate: C;
+  score: number;
+  field: MatchFieldName | undefined;
+  ranges: MatchRange[];
+}
+
+interface Field {
+  name: MatchFieldName;
+  text: string;
+  weight: number;
+}
+
+interface Embedding {
+  score: number;
+  positions: number[];
+}
+
+interface RankedResult<C extends MatchCandidate> extends MatchResult<C> {
+  matchedText: string;
+  inputIndex: number;
+}
+
+const KIND_ORDER: Record<CandidateKind, number> = {
+  session: 0,
+  command: 1,
+  directory: 2,
+};
+
+function fields(candidate: MatchCandidate): Field[] {
+  switch (candidate.kind) {
+    case "session": {
+      const values: Array<[MatchFieldName, string | undefined, number]> = [
+        ["name", candidate.fields.name, 0],
+        ["directory", candidate.fields.directory, -24],
+        ["command", candidate.fields.command, -32],
+        ["tool", candidate.fields.tool, -40],
+      ];
+      return values.flatMap(([name, text, weight]) =>
+        text === undefined ? [] : [{ name, text, weight }],
+      );
+    }
+    case "command":
+      return [{ name: "label", text: candidate.fields.label, weight: 0 }];
+    case "directory":
+      return [{ name: "path", text: candidate.fields.path, weight: 0 }];
+  }
+}
+
+function normalizeQuery(query: string): string {
+  return query.toLowerCase().replace(/\s/g, "");
+}
+
+function boundaryBonus(text: string, position: number): number {
+  if (position === 0) return 18;
+
+  const previous = text[position - 1];
+  if ("/\\-_ .:".includes(previous)) return 16;
+
+  const current = text[position];
+  const isUppercase = current !== current.toLowerCase() && current === current.toUpperCase();
+  const previousIsLowercase =
+    previous !== previous.toUpperCase() && previous === previous.toLowerCase();
+  if (isUppercase && previousIsLowercase) return 12;
+
+  const isDigit = current >= "0" && current <= "9";
+  const previousIsDigit = previous >= "0" && previous <= "9";
+  if (isDigit && !previousIsDigit) return 12;
+
+  return 0;
+}
+
+function contribution(text: string, position: number, previousPosition: number): number {
+  const gap = position - previousPosition - 1;
+  return 16 + boundaryBonus(text, position) + (gap === 0 ? 8 : -Math.min(gap, 12));
+}
+
+function isBetterEmbedding(candidate: Embedding, incumbent: Embedding | undefined): boolean {
+  if (!incumbent || candidate.score !== incumbent.score) {
+    return !incumbent || candidate.score > incumbent.score;
+  }
+  for (let index = 0; index < candidate.positions.length; index++) {
+    if (candidate.positions[index] !== incumbent.positions[index]) {
+      return candidate.positions[index] < incumbent.positions[index];
+    }
+  }
+  return false;
+}
+
+function bestEmbedding(query: string, text: string): Embedding | undefined {
+  const lowerText = text.toLowerCase();
+  let previousStates = new Map<number, Embedding>();
+
+  for (let queryIndex = 0; queryIndex < query.length; queryIndex++) {
+    const states = new Map<number, Embedding>();
+    for (let position = 0; position < lowerText.length; position++) {
+      if (lowerText[position] !== query[queryIndex]) continue;
+
+      if (queryIndex === 0) {
+        states.set(position, {
+          score: contribution(text, position, -1),
+          positions: [position],
+        });
+        continue;
+      }
+
+      for (const [previousPosition, previous] of previousStates) {
+        if (previousPosition >= position) continue;
+        const candidate = {
+          score: previous.score + contribution(text, position, previousPosition),
+          positions: [...previous.positions, position],
+        };
+        if (isBetterEmbedding(candidate, states.get(position))) states.set(position, candidate);
+      }
+    }
+    if (states.size === 0) return undefined;
+    previousStates = states;
+  }
+
+  let best: Embedding | undefined;
+  for (const embedding of previousStates.values()) {
+    if (isBetterEmbedding(embedding, best)) best = embedding;
+  }
+  return best;
+}
+
+function toRanges(positions: number[]): MatchRange[] {
+  const ranges: MatchRange[] = [];
+  for (const position of positions) {
+    const previous = ranges[ranges.length - 1];
+    if (previous && previous[1] === position) {
+      ranges[ranges.length - 1] = [previous[0], position + 1];
+    } else {
+      ranges.push([position, position + 1]);
+    }
+  }
+  return ranges;
+}
+
+function compareByCodePoint(left: string, right: string): number {
+  const leftPoints = Array.from(left, (character) => character.codePointAt(0)!);
+  const rightPoints = Array.from(right, (character) => character.codePointAt(0)!);
+  const length = Math.min(leftPoints.length, rightPoints.length);
+  for (let index = 0; index < length; index++) {
+    if (leftPoints[index] !== rightPoints[index]) return leftPoints[index] - rightPoints[index];
+  }
+  return leftPoints.length - rightPoints.length;
+}
+
+export function matchAndRank<C extends MatchCandidate>(
+  query: string,
+  candidates: readonly C[],
+): MatchResult<C>[] {
+  const normalizedQuery = normalizeQuery(query);
+  if (normalizedQuery === "") {
+    return candidates.map((candidate) => ({ candidate, score: 0, field: undefined, ranges: [] }));
+  }
+
+  const results: RankedResult<C>[] = [];
+  candidates.forEach((candidate, inputIndex) => {
+    let best:
+      | { field: Field; score: number; positions: number[] }
+      | undefined;
+
+    for (const field of fields(candidate)) {
+      const embedding = bestEmbedding(normalizedQuery, field.text);
+      if (!embedding) continue;
+
+      const compactText = field.text.toLowerCase().replace(/\s/g, "");
+      const adjustment =
+        compactText === normalizedQuery ? 64 : compactText.startsWith(normalizedQuery) ? 32 : 0;
+      const score = embedding.score + adjustment + field.weight;
+      if (!best || score > best.score) best = { field, score, positions: embedding.positions };
+    }
+
+    if (best) {
+      results.push({
+        candidate,
+        score: best.score,
+        field: best.field.name,
+        ranges: toRanges(best.positions),
+        matchedText: best.field.text,
+        inputIndex,
+      });
+    }
+  });
+
+  results.sort(
+    (left, right) =>
+      right.score - left.score ||
+      KIND_ORDER[left.candidate.kind] - KIND_ORDER[right.candidate.kind] ||
+      left.matchedText.length - right.matchedText.length ||
+      compareByCodePoint(left.matchedText, right.matchedText) ||
+      left.inputIndex - right.inputIndex,
+  );
+
+  return results.map(({ candidate, score, field, ranges }) => ({ candidate, score, field, ranges }));
+}

web/src/multiview.test.ts

@@ -36,6 +36,7 @@ function fakeSidebar(): SidebarHandle {
     el: document.createElement("aside"),
     setActive() {},
     setHighlights() {},
+    setPreview() {},
     focusList() {},
     hasListFocus() {
       return false;

web/src/multiview.ts

@@ -221,6 +221,12 @@ export function createMultiView(opts: MultiViewOptions): MultiView {
     const tab = activeTab(layout);
     for (const pane of canvas.querySelectorAll<HTMLElement>(".mv-pane")) {
       pane.classList.toggle("is-focused", pane.dataset.leafId === tab.focusedLeafId);
+      // The previewed pane's titlebar wears the preview colour instead of the
+      // accent tint a focused pane gets (docs/PREVIEW.md).
+      pane.classList.toggle(
+        "is-preview",
+        preview !== null && pane.dataset.sessionId === preview.sessionId,
+      );
     }
     // A preview is not a focused pane: reporting it would clear the session's
     // `AwaitingInput` glow just because the operator scrolled past it.
@@ -229,6 +235,9 @@ export function createMultiView(opts: MultiViewOptions): MultiView {
       open: realOpenSessions(),
       focused: focusedLeafSession(),
     });
+    // The row the preview came from wears the same colour, so the sidebar and
+    // the pane read as one thing rather than two unrelated highlights.
+    sidebar.setPreview(preview?.sessionId ?? null);
   }
 
   function focusLeaf(leafId: string): void {
@@ -549,6 +558,7 @@ export function createMultiView(opts: MultiViewOptions): MultiView {
       if (!preview) pool.setFocus(null);
       canvas.appendChild(renderWelcome());
       sidebar.setHighlights({ open: realOpenSessions(), focused: null });
+      sidebar.setPreview(preview?.sessionId ?? null);
       persist();
       return;
     }
@@ -588,6 +598,7 @@ export function createMultiView(opts: MultiViewOptions): MultiView {
 
     const pane = buildPane(focused);
     pane.el.classList.add("is-focused"); // the only pane — never dimmed
+    if (preview && focused.sessionId === preview.sessionId) pane.el.classList.add("is-preview");
     wrap.appendChild(pane.el);
     canvas.appendChild(wrap);
 
@@ -598,6 +609,7 @@ export function createMultiView(opts: MultiViewOptions): MultiView {
     );
     if (!preview) pool.setFocus(focused.sessionId ?? null);
     sidebar.setHighlights({ open: realOpenSessions(), focused: focused.sessionId ?? null });
+    sidebar.setPreview(preview?.sessionId ?? null);
   }
 
   function closeSession(sessionId: string): void {

web/src/preview.test.ts

@@ -45,11 +45,17 @@ function fakePool(): Spy {
   return { pool, visible: () => visible, focusCalls, mountedWithFocus };
 }
 
+/** Last value the controller pushed to `SidebarHandle.setPreview`. */
+const previewRow: { id: string | null } = { id: null };
+
 function fakeSidebar(): SidebarHandle {
   return {
     el: document.createElement("aside"),
     setActive() {},
     setHighlights() {},
+    setPreview(id: string | null) {
+      previewRow.id = id;
+    },
     focusList() {},
     hasListFocus() {
       return false;
@@ -88,6 +94,7 @@ describe("sidebar preview", () => {
   beforeEach(() => {
     stubFetch();
     document.body.replaceChildren();
+    previewRow.id = null;
   });
 
   afterEach(() => {
@@ -110,6 +117,23 @@ describe("sidebar preview", () => {
     expect(serializeLayout(layout)).toEqual(before);
   });
 
+  it("marks the previewed pane and its sidebar row, and unmarks them after", () => {
+    const layout = twoTabs();
+    const spy = fakePool();
+    const mv = makeMv(layout, spy.pool);
+
+    mv.previewSession("s1");
+    expect(previewRow.id).toBe("s1");
+    expect(mv.el.querySelectorAll(".mv-pane.is-preview")).toHaveLength(1);
+    expect(
+      (mv.el.querySelector(".mv-pane.is-preview") as HTMLElement).dataset.sessionId,
+    ).toBe("s1");
+
+    mv.previewSession(null);
+    expect(previewRow.id).toBeNull();
+    expect(mv.el.querySelectorAll(".mv-pane.is-preview")).toHaveLength(0);
+  });
+
   it("shows a session no pane holds in a throwaway tab that leaves no trace", () => {
     const layout = twoTabs();
     const before = serializeLayout(layout);

web/src/previewSchedule.test.ts

@@ -0,0 +1,92 @@
+import { describe, expect, it } from "vitest";
+
+import { createPreviewSchedule, PREVIEW_MIN_GAP_MS } from "./previewSchedule.js";
+
+/** Hand-driven clock + timer queue, so the schedule is asserted without waiting. */
+function harness() {
+  let now = 1_000;
+  const timers = new Map<number, { at: number; fn: () => void }>();
+  let nextHandle = 1;
+  const emitted: (string | null)[] = [];
+
+  const schedule = createPreviewSchedule((id) => emitted.push(id), {
+    now: () => now,
+    setTimer: (fn, ms) => {
+      const h = nextHandle++;
+      timers.set(h, { at: now + ms, fn });
+      return h;
+    },
+    clearTimer: (h) => {
+      timers.delete(h);
+    },
+  });
+
+  /** Advance the clock, firing any timer that comes due. */
+  const advance = (ms: number) => {
+    now += ms;
+    for (const [h, t] of [...timers]) {
+      if (t.at <= now) {
+        timers.delete(h);
+        t.fn();
+      }
+    }
+  };
+
+  return { schedule, emitted, advance };
+}
+
+describe("preview schedule", () => {
+  it("shows the first preview immediately", () => {
+    const { schedule, emitted } = harness();
+    schedule("s1");
+    expect(emitted).toEqual(["s1"]);
+  });
+
+  it("coalesces a burst into one trailing preview", () => {
+    const { schedule, emitted, advance } = harness();
+    // A pointer sweep across the list, or j held down: every row in between
+    // is walked well inside one gap.
+    schedule("s1");
+    schedule("s2");
+    schedule("s3");
+    expect(emitted).toEqual(["s1"]);
+    advance(PREVIEW_MIN_GAP_MS);
+    expect(emitted).toEqual(["s1", "s3"]);
+  });
+
+  it("shows the next preview immediately once the gap has passed", () => {
+    const { schedule, emitted, advance } = harness();
+    schedule("s1");
+    advance(PREVIEW_MIN_GAP_MS);
+    schedule("s2");
+    expect(emitted).toEqual(["s1", "s2"]);
+  });
+
+  it("drops a superseded trailing preview rather than replaying it", () => {
+    const { schedule, emitted, advance } = harness();
+    schedule("s1");
+    schedule("s2");
+    schedule("s1"); // back where we started inside the same gap
+    advance(PREVIEW_MIN_GAP_MS);
+    // s1 is already on screen, so the trailing edge has nothing to do.
+    expect(emitted).toEqual(["s1"]);
+  });
+
+  it("clears through the same gap, so leaving and re-entering does not blink", () => {
+    const { schedule, emitted, advance } = harness();
+    schedule("s1");
+    schedule(null); // pointer crosses the gap between two rows
+    schedule("s2");
+    advance(PREVIEW_MIN_GAP_MS);
+    expect(emitted).toEqual(["s1", "s2"]);
+  });
+
+  it("cancel drops a pending trailing preview", () => {
+    const { schedule, emitted, advance } = harness();
+    schedule("s1");
+    schedule("s2");
+    schedule.cancel();
+    advance(PREVIEW_MIN_GAP_MS);
+    expect(emitted).toEqual(["s1"]);
+  });
+});

web/src/previewSchedule.ts

@@ -0,0 +1,87 @@
+/**
+ * When the content pane follows the sidebar highlight (docs/PREVIEW.md).
+ *
+ * The highlight itself is never scheduled — that is a class on a row and lands
+ * on the same frame as the input. This governs only the pane swap behind it,
+ * which mounts a terminal and, for a session the connection pool isn't already
+ * holding, opens an attach socket the daemon answers with a `tmux capture-pane`.
+ *
+ * A plain debounce would put that cost in front of every preview, including the
+ * one preview the operator actually meant. Instead the first move shows at once
+ * and the rest of a burst is coalesced: walking a list with `j` held down, or
+ * sweeping the pointer from the top of the sidebar to the bottom, costs one
+ * preview at the start and one at the row you stopped on, not one per row.
+ */
+
+/** Shortest gap between two pane swaps. Long enough that a fast walk mounts a
+ *  couple of terminals rather than one per row; short enough that a deliberate
+ *  second move never waits on it. */
+export const PREVIEW_MIN_GAP_MS = 120;
+
+export interface PreviewScheduleDeps {
+  now?: () => number;
+  setTimer?: (fn: () => void, ms: number) => number;
+  clearTimer?: (handle: number) => void;
+  /** Override the gap; tests and callers otherwise take {@link PREVIEW_MIN_GAP_MS}. */
+  minGapMs?: number;
+}
+
+export interface PreviewSchedule {
+  (sessionId: string | null): void;
+  /** Drop a pending trailing preview without showing it. */
+  cancel(): void;
+}
+
+/**
+ * Wrap `show` so it fires on the leading edge and at most once per gap.
+ *
+ * `show` is called with the session to preview, or `null` to put back whatever
+ * the operator actually opened.
+ */
+export function createPreviewSchedule(
+  show: (sessionId: string | null) => void,
+  deps: PreviewScheduleDeps = {},
+): PreviewSchedule {
+  const now = deps.now ?? (() => Date.now());
+  const setTimer = deps.setTimer ?? ((fn, ms) => window.setTimeout(fn, ms));
+  const clearTimer = deps.clearTimer ?? ((h) => window.clearTimeout(h));
+  const minGap = deps.minGapMs ?? PREVIEW_MIN_GAP_MS;
+
+  let lastShownAt = Number.NEGATIVE_INFINITY;
+  let shown: string | null | undefined;
+  let pendingTimer: number | undefined;
+  let pendingId: string | null = null;
+
+  const emit = (id: string | null) => {
+    // Nothing to do when the burst ended on the view already up: re-showing it
+    // would tear down and re-mount the pane for no visible change.
+    if (shown === id) return;
+    shown = id;
+    lastShownAt = now();
+    show(id);
+  };
+
+  const cancelPending = () => {
+    if (pendingTimer === undefined) return;
+    clearTimer(pendingTimer);
+    pendingTimer = undefined;
+  };
+
+  const schedule = ((sessionId: string | null) => {
+    pendingId = sessionId;
+    const waited = now() - lastShownAt;
+    if (waited >= minGap) {
+      cancelPending();
+      emit(sessionId);
+      return;
+    }
+    if (pendingTimer !== undefined) return; // already waiting; `pendingId` wins
+    pendingTimer = setTimer(() => {
+      pendingTimer = undefined;
+      emit(pendingId);
+    }, minGap - waited);
+  }) as PreviewSchedule;
+
+  schedule.cancel = cancelPending;
+  return schedule;
+}

web/src/sidebarNav.test.ts

@@ -169,33 +169,30 @@ describe("sidebar keyboard navigation", () => {
 
 describe("sidebar preview requests (docs/PREVIEW.md)", () => {
   it("asks for a preview on every keyboard step, and for none once the list blurs", () => {
-    const seen: [string | null, string][] = [];
-    const { el } = twoFolders({ onPreview: (id, source) => seen.push([id, source]) });
+    const seen: (string | null)[] = [];
+    const { el } = twoFolders({ onPreview: (id) => seen.push(id) });
 
     press(tree(el), "j");
     press(tree(el), "j");
-    expect(seen).toEqual([
-      [A, "key"],
-      [B, "key"],
-    ]);
+    expect(seen).toEqual([A, B]);
 
     tree(el).dispatchEvent(new FocusEvent("blur"));
-    expect(seen.at(-1)).toEqual([null, "key"]);
+    expect(seen.at(-1)).toBe(null);
   });
 
   it("asks for a preview of the hovered card, and clears it on the way out", () => {
-    const seen: [string | null, string][] = [];
-    const { el } = twoFolders({ onPreview: (id, source) => seen.push([id, source]) });
+    const seen: (string | null)[] = [];
+    const { el } = twoFolders({ onPreview: (id) => seen.push(id) });
     const card = el.querySelectorAll<HTMLElement>(".tree-leaf")[0];
 
     card.dispatchEvent(new PointerEvent("pointerover", { bubbles: true, pointerType: "mouse" }));
-    expect(seen).toEqual([[A, "hover"]]);
+    expect(seen).toEqual([A]);
     // Moving within the same card is not a new preview.
     card.dispatchEvent(new PointerEvent("pointerover", { bubbles: true, pointerType: "mouse" }));
     expect(seen).toHaveLength(1);
 
     tree(el).dispatchEvent(new PointerEvent("pointerleave", { pointerType: "mouse" }));
-    expect(seen.at(-1)).toEqual([null, "hover"]);
+    expect(seen.at(-1)).toBe(null);
   });
 
   it("ignores touch, where a tap already opens the session", () => {

web/src/styles.css

@@ -87,6 +87,30 @@
   --accent-tint: oklch(0.92 0.005 256 / 0.1);
   --accent-ring: oklch(0.92 0.005 256 / 0.5);
 
+  /* preview (docs/PREVIEW.md): a provisional view needs a colour that is not
+     the accent, because the accent is what says "this is the one you picked".
+     Defined once, off a single hue variable, so a palette whose accent already
+     sits on that hue can move it (see periwinkle/orchid below); `light-dark()`
+     keeps the light pair here instead of in all eighteen theme blocks. */
+  --preview-h: 305;
+  --preview: light-dark(
+    oklch(0.55 0.16 var(--preview-h)),
+    oklch(0.78 0.14 var(--preview-h))
+  );
+  --preview-ink: light-dark(
+    oklch(0.99 0.005 var(--preview-h)),
+    oklch(0.19 0.045 var(--preview-h))
+  );
+  /* Opaque, not a wash: session rows read as fills, and a fill has to land on
+     the same colour whatever tier the row was already painted. `--accent-fill`
+     is the same recipe on the accent, so the two tiers differ by hue alone. */
+  --preview-tint: color-mix(in oklab, var(--preview) 30%, var(--surface-2));
+  --accent-fill: color-mix(in oklab, var(--accent) 30%, var(--surface-2));
+  --preview-ring: light-dark(
+    oklch(0.55 0.16 var(--preview-h) / 0.5),
+    oklch(0.78 0.14 var(--preview-h) / 0.6)
+  );
+
   --live: oklch(0.84 0.17 152);
   --live-glow: oklch(0.84 0.17 152 / 0.55);
 
@@ -256,6 +280,9 @@
   --accent-ink: oklch(0.18 0.04 278);
   --accent-tint: oklch(0.75 0.125 275 / 0.14);
   --accent-ring: oklch(0.75 0.125 275 / 0.55);
+  /* This accent is already violet, so preview moves to cyan to stay legible
+     as "not the accent". Set once here: the light blocks below don't touch it. */
+  --preview-h: 195;
   --term-bg: oklch(0.155 0.018 278);
 }
 :root[data-palette="periwinkle"][data-theme="light"],
@@ -437,6 +464,8 @@
   --accent-ink: oklch(0.22 0.05 310);
   --accent-tint: oklch(0.78 0.13 310 / 0.14);
   --accent-ring: oklch(0.78 0.13 310 / 0.55);
+  /* Same collision as periwinkle: an orchid accent needs a non-purple preview. */
+  --preview-h: 195;
   --term-bg: oklch(0.155 0.014 305);
 }
 :root[data-palette="orchid"][data-theme="light"],
@@ -1064,7 +1093,6 @@ textarea {
   cursor: pointer;
   font-family: var(--font-mono);
   font-size: var(--fs-12);
-  transition: color var(--dur-fast) var(--ease-out);
 }
 
 .tree-folder-header:hover {
@@ -1076,9 +1104,9 @@ textarea {
   text-align: center;
   color: var(--faint);
   font-size: var(--fs-11);
-  transition:
-    transform var(--dur) var(--ease-out),
-    color var(--dur-fast) var(--ease-out);
+  /* The rotation is the collapse animation and stays; the hover colour is
+     immediate, like the row's own hover. */
+  transition: transform var(--dur) var(--ease-out);
 }
 
 .tree-folder-header[aria-expanded="false"] .chevron {
@@ -1115,33 +1143,42 @@ textarea {
   border-radius: var(--r-1);
   color: var(--ink);
   position: relative;
-  transition:
-    background var(--dur-fast) var(--ease-out),
-    box-shadow var(--dur-fast) var(--ease-out);
+  /* No transition on `background`: it is what hover, the keyboard cursor and
+     the preview all paint, and easing it puts a visible delay between the input
+     landing on a row and the row admitting it. `.is-active`'s ring still eases
+     — being open in a pane is a state, not a response to the pointer. */
+  transition: box-shadow var(--dur-fast) var(--ease-out);
 }
 
-/* "Alive" reads as a faint wash on the row itself — no per-row status icon. */
-.tree-leaf[data-status="running"] {
+/* Session-row tiers (docs/SIDEBAR.md). A row is usually several of these at
+   once, so every qualifier below sits in `:where()`: each rule is worth the
+   same specificity and the ladder is decided purely by the order they appear
+   in, latest wins. Add a tier where it belongs in that order, not by piling on
+   another class to out-weigh the rule above it. Each tier paints a background
+   and nothing else — the list says all of this with fill, never an edge. */
+
+/* 1. Alive. A faint wash on the row itself — no per-row status icon. */
+.tree-leaf:where([data-status="running"]) {
   background: color-mix(in oklab, var(--accent) 6%, transparent);
 }
 
-.tree-leaf:hover {
-  background: var(--surface-2);
+/* 2. Under the pointer, or under the keyboard walk. Both are what previews a
+   row (docs/PREVIEW.md), so both read in the preview hue — never the accent,
+   which belongs to the row actually open. */
+.tree-leaf:where(:hover, .is-highlighted) {
+  background: color-mix(in oklab, var(--preview) 12%, var(--surface-2));
 }
 
-.tree-leaf[data-status="running"]:hover {
-  background: color-mix(in oklab, var(--accent) 13%, var(--surface-2));
+.tree-leaf:where([data-status="running"]):where(:hover, .is-highlighted) {
+  background: color-mix(in oklab, var(--preview) 18%, var(--surface-2));
 }
 
-.tree-leaf:focus-visible {
+.tree-leaf:where(:focus-visible) {
   outline: none;
   background: color-mix(in oklab, var(--accent) 16%, var(--surface-2));
 }
 
-/* Where the keyboard walk (j/k) is standing. Distinct from `.is-active`: this
-   is a cursor, not a statement about what is mounted, so it reads as a ring
-   rather than a fill and the two can sit on the same row. */
-.tree-leaf.is-highlighted,
+/* A folder row previews nothing, so its cursor stays a ring. */
 .tree-folder-header.is-highlighted {
   box-shadow: inset 0 0 0 2px var(--accent-ring);
 }
@@ -1150,17 +1187,26 @@ textarea {
   outline: none;
 }
 
-/* The session currently mounted in the content pane. */
-.tree-leaf.is-active,
-.tree-leaf.is-active[data-status="running"] {
-  background: var(--accent-tint);
-  box-shadow: inset 0 0 0 1px var(--accent-ring);
+/* 3. Open in some pane, but not the focused one (issue #33). */
+.tree-leaf:where(.is-open) {
+  background: color-mix(in oklab, var(--accent) 6%, transparent);
+}
+
+/* 4. The session currently mounted in the content pane. */
+.tree-leaf:where(.is-active) {
+  background: var(--accent-fill);
 }
 
 .tree-leaf.is-active .leaf-name {
   color: var(--ink);
 }
 
+/* 5. The row the content pane is previewing right now. Last, so previewing a
+   session that is already open still reads as provisional. */
+.tree-leaf:where(.is-previewing) {
+  background: var(--preview-tint);
+}
+
 /* Exited sessions recede: dimmed name + an "exited" badge carry status, so it's
    never the running tint's absence alone doing the work. */
 .tree-leaf[data-status="dead"] {
@@ -1377,6 +1423,147 @@ input.leaf-rename:focus {
   color: var(--muted);
 }
 
+/* ---------- command bar (Ctrl+K) — docs/COMMAND-BAR.md ---------- */
+/* Same family of surface as the spawn modal and the help overlay: the overlay
+   tokens below are theirs, not a third set. */
+.cmdbar-overlay {
+  position: fixed;
+  inset: 0;
+  z-index: var(--z-modal);
+  display: grid;
+  grid-template-rows: 12vh auto 1fr;
+  justify-items: center;
+  padding: var(--sp-4);
+  background: oklch(0 0 0 / 0.5);
+  backdrop-filter: blur(4px);
+}
+
+.cmdbar-panel {
+  grid-row: 2;
+  display: flex;
+  flex-direction: column;
+  width: min(560px, 100%);
+  max-height: min(60vh, 520px);
+  overflow: hidden;
+  background: var(--surface);
+  border: 1px solid var(--border-strong);
+  border-radius: var(--r-3);
+  box-shadow: var(--shadow-2);
+}
+
+.cmdbar-input {
+  appearance: none;
+  background: none;
+  border: 0;
+  border-bottom: 1px solid var(--border);
+  border-radius: 0;
+  color: var(--ink);
+  font-family: var(--font-mono);
+  font-size: var(--fs-15);
+  padding: var(--sp-3) var(--sp-4);
+}
+
+.cmdbar-input:focus-visible {
+  outline: none;
+}
+
+.cmdbar-results {
+  overflow-y: auto;
+  padding: var(--sp-2) 0;
+}
+
+.cmdbar-group-title {
+  padding: var(--sp-2) var(--sp-4) var(--sp-1);
+  font-size: var(--fs-11);
+  font-weight: 600;
+  letter-spacing: 0.08em;
+  text-transform: uppercase;
+  color: var(--faint);
+}
+
+.cmdbar-row {
+  display: flex;
+  align-items: baseline;
+  gap: var(--sp-3);
+  padding: var(--sp-1) var(--sp-4);
+  cursor: pointer;
+}
+
+.cmdbar-row.is-active {
+  background: var(--surface-3);
+}
+
+.cmdbar-row-name {
+  font-size: var(--fs-13);
+  color: var(--ink);
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+
+/* A dead session still lists — it just is not where you just were. */
+.cmdbar-row.is-dead .cmdbar-row-name {
+  color: var(--muted);
+}
+
+.cmdbar-row-meta {
+  flex: 1 1 auto;
+  min-width: 0;
+  font-size: var(--fs-11);
+  color: var(--faint);
+  text-align: right;
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+
+/* A command row's chord, shown so the bar teaches the keymap. */
+.cmdbar-row-keys {
+  flex: 1 1 auto;
+  display: flex;
+  justify-content: flex-end;
+  gap: var(--sp-1);
+  min-width: 0;
+}
+
+.cmdbar-row-keys kbd {
+  font-family: var(--font-mono);
+  font-size: var(--fs-11);
+  color: var(--muted);
+  background: var(--surface-2);
+  border: 1px solid var(--border);
+  border-radius: var(--r-1);
+  padding: 0 var(--sp-1);
+}
+
+.cmdbar-hit {
+  background: none;
+  color: var(--accent);
+  font-weight: 600;
+}
+
+.cmdbar-empty {
+  padding: var(--sp-3) var(--sp-4);
+  font-size: var(--fs-13);
+  color: var(--muted);
+}
+
+/* Phone: the bottom-sheet treatment the spawn modal already uses. */
+@media (max-width: 600px) {
+  .cmdbar-overlay {
+    grid-template-rows: 1fr auto;
+    padding: 0;
+  }
+
+  .cmdbar-panel {
+    grid-row: 2;
+    width: 100%;
+    max-height: 70vh;
+    border-radius: var(--r-3) var(--r-3) 0 0;
+    border-bottom: 0;
+  }
+}
+
 /* 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 {
@@ -2884,10 +3071,14 @@ input.leaf-rename:focus {
 }
 
 /* Preview (docs/PREVIEW.md): the content pane is showing a session the
-   operator only highlighted, so it reads as provisional — a dashed tab and a
-   dashed inset ring on the canvas — and reverts when the highlight moves. */
+   operator only highlighted, so it reads as provisional — the preview hue on
+   the pane's titlebar, a dashed tab, a dashed inset ring on the canvas — and
+   reverts when the highlight moves. The hue is deliberately not the accent:
+   the accent means "this is what you picked", which a preview is not. */
 .mv-tab.is-preview {
   border-style: dashed;
+  border-color: var(--preview-ring);
+  color: var(--preview);
   font-style: italic;
 }
 .mv.mv-previewing .mv-canvas::before {
@@ -2900,8 +3091,8 @@ input.leaf-rename:focus {
   border-radius: var(--r-1);
   font: 500 var(--fs-11) / 1.5 var(--font-mono);
   letter-spacing: 0.04em;
-  color: var(--accent-ink);
-  background: var(--accent);
+  color: var(--preview-ink);
+  background: var(--preview);
   opacity: 0.85;
   pointer-events: none;
 }
@@ -2910,7 +3101,7 @@ input.leaf-rename:focus {
   position: absolute;
   inset: 0;
   pointer-events: none;
-  border: 1px dashed var(--accent-ring);
+  border: 1px dashed var(--preview-ring);
   border-radius: var(--r-1);
   z-index: var(--z-sticky);
 }
@@ -3028,6 +3219,15 @@ input.leaf-rename:focus {
 .mv-pane:not(.is-focused) .attach-header {
   opacity: 0.7;
 }
+/* The previewed pane's titlebar carries the preview hue, so the chip is not the
+   only thing saying the pane is provisional — and so it is never mistaken for
+   the accent tint of the pane the operator actually focused. It keeps full
+   strength even though a preview never takes focus. */
+.mv-pane.is-preview .attach-header,
+.mv-pane.is-preview.is-focused .attach-header {
+  background: color-mix(in oklab, var(--preview) 34%, var(--surface));
+  opacity: 1;
+}
 /* A pane with no session yet: a quiet hint rather than blank terminal black. */
 .mv-pane-empty {
   flex: 1;
@@ -3117,13 +3317,6 @@ input.leaf-rename:focus {
   border-radius: var(--r-1);
 }
 
-/* sidebar two-tier highlight (issue #33).
-   .is-active = focused pane (loud, from existing rule); .is-open = open
-   elsewhere (quiet). */
-.tree-leaf.is-open {
-  background: color-mix(in oklab, var(--accent) 6%, transparent);
-}
-
 /* =========================================================================
    multi-view mobile (#35): below 860px only the focused pane is shown — no tab
    bar, no pane switcher; the sidebar drawer (☰) is the navigation.

web/src/types.ts

@@ -50,6 +50,12 @@ export interface Session {
    * create one. `base_repo` is the repository's main checkout, which is what
    * the session tree groups by (#99). */
   worktree?: SessionWorktree | null;
+  /** Wall-clock of when this session last became the pane a client was showing
+   * (#145) — stamped by both `POST /api/sessions/:id/focus` and opening
+   * `/api/attach/:id`. Absent until the session has been focused once, which is
+   * how the command bar's empty query sorts a never-focused session after every
+   * session that has one (`docs/COMMAND-BAR.md`). */
+  last_focused_at?: IsoTimestamp | null;
 }
 
 /** A session's daemon-created worktree (`SessionWorktree` on the wire). */