fix(maestro): leader twice sends one literal leader byte

ctrl-a is consumed as the leader on every press, so it never reaches the
shell and readline's beginning-of-line was gone with no way back — unlike
Ctrl-K, which already has an escape hatch. Fix it the way tmux does:
pressing the leader twice sends the literal leader byte to the focused
pane and clears the pending chord, on both web and TUI, built from the
configured leader so a rebound leader carries it.

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

crates/maestro-tui/src/action.rs

@@ -56,6 +56,14 @@ pub enum Action {
     /// Open the `ctrl-k` command bar (`docs/COMMAND-BAR.md`) — a query line
     /// over the sessions, ranked by the shared matcher.
     OpenCommandBar,
+    /// Escape hatch (#156): leader then `ctrl-k` sends the literal `0x0B`
+    /// byte to the focused pane instead of opening the command bar, giving
+    /// readline's kill-to-end-of-line back.
+    SendLiteralCtrlK,
+    /// Escape hatch (#158): the leader pressed twice sends one literal
+    /// leader byte to the focused pane and drops the pending chord, the way
+    /// tmux resolves a doubled prefix key.
+    SendLiteralLeader,
     ToggleSidebar,
     ShowHelp,
     Quit,
@@ -98,6 +106,8 @@ impl Action {
             Action::KillHighlighted => "Kill selected session".into(),
             Action::RenameHighlighted => "Rename selected session".into(),
             Action::OpenCommandBar => "Go to a session".into(),
+            Action::SendLiteralCtrlK => "Send literal Ctrl-K to session".into(),
+            Action::SendLiteralLeader => "Send literal leader key to session".into(),
             Action::ToggleSidebar => "Show or hide sidebar".into(),
             Action::ShowHelp => "Show help".into(),
             Action::Quit => "Quit Maestro".into(),
@@ -125,6 +135,8 @@ impl Action {
             "KillHighlighted" => return Ok(Action::KillHighlighted),
             "RenameHighlighted" => return Ok(Action::RenameHighlighted),
             "OpenCommandBar" => return Ok(Action::OpenCommandBar),
+            "SendLiteralCtrlK" => return Ok(Action::SendLiteralCtrlK),
+            "SendLiteralLeader" => return Ok(Action::SendLiteralLeader),
             "ToggleSidebar" => return Ok(Action::ToggleSidebar),
             "ShowHelp" => return Ok(Action::ShowHelp),
             "Quit" => return Ok(Action::Quit),
@@ -256,11 +268,26 @@ mod tests {
         assert_eq!(Action::OpenCommandBar.help_label(), "Go to a session");
     }
 
+    /// The escape hatch (#156) is an ordinary action like any other.
+    #[test]
+    fn send_literal_ctrl_k_round_trips() {
+        assert_eq!(
+            Action::parse("SendLiteralCtrlK").unwrap(),
+            Action::SendLiteralCtrlK
+        );
+        assert_eq!(Action::SendLiteralCtrlK.to_string(), "SendLiteralCtrlK");
+        assert_eq!(
+            Action::SendLiteralCtrlK.help_label(),
+            "Send literal Ctrl-K to session"
+        );
+    }
+
     #[test]
     fn display_round_trips() {
         for a in [
             Action::EnterInsert,
             Action::OpenCommandBar,
+            Action::SendLiteralCtrlK,
             Action::RenameHighlighted,
             Action::Quit,
             Action::OpenSpawnModal,

crates/maestro-tui/src/app.rs

@@ -306,6 +306,7 @@ impl App {
                     return Ok(true);
                 }
             }
+            self.chord.take_replay();
             return Ok(false);
         }
 
@@ -325,32 +326,46 @@ impl App {
             return Ok(false);
         }
 
-        let known = self.cfg.keymap.known_bindings(self.state.mode);
-        match self.chord.feed(&key, &known) {
-            ChordResult::Pending => Ok(false),
-            ChordResult::Resolved(canon) => {
-                let act = self.cfg.keymap.resolve(self.state.mode, &canon);
-                if matches!(act, Some(Action::Quit)) {
-                    return Ok(true);
+        // A key bumped out of an abandoned chord (#156) is replayed as its
+        // own keystroke, against the mode dispatch may have just changed.
+        let mut current_key = key;
+        let mut result = self.chord.feed(
+            &current_key,
+            &self.cfg.keymap.known_bindings(self.state.mode),
+        );
+        loop {
+            let canon = match result {
+                ChordResult::Pending => return Ok(false),
+                ChordResult::Resolved(canon) => canon,
+            };
+            let act = self.cfg.keymap.resolve(self.state.mode, &canon);
+            if matches!(act, Some(Action::Quit)) {
+                return Ok(true);
+            }
+            let pty_owns_keys =
+                self.state.mode == Mode::Insert && matches!(self.state.focus, Focus::Pane);
+            match act {
+                // `Noop` suppresses a binding, and a key with no binding in
+                // Insert mode is the session's — so a key bound to `Noop`
+                // reaches the pty too. That is the escape hatch for taking
+                // a default binding back.
+                Some(Action::Noop) | None if pty_owns_keys => {
+                    let effects = self.forward_to_session(&current_key).into_iter().collect();
+                    self.perform(effects).await;
                 }
-                let pty_owns_keys =
-                    self.state.mode == Mode::Insert && matches!(self.state.focus, Focus::Pane);
-                match act {
-                    // `Noop` suppresses a binding, and a key with no binding in
-                    // Insert mode is the session's — so a key bound to `Noop`
-                    // reaches the pty too. That is the escape hatch for taking
-                    // a default binding back.
-                    Some(Action::Noop) | None if pty_owns_keys => {
-                        let effects = self.forward_to_session(&key).into_iter().collect();
-                        self.perform(effects).await;
-                    }
-                    Some(act) => {
-                        let effects = self.dispatch(act);
-                        self.perform(effects).await;
-                    }
-                    None => {}
+                Some(act) => {
+                    let effects = self.dispatch(act);
+                    self.perform(effects).await;
                 }
-                Ok(false)
+                None => {}
+            }
+            match self.chord.take_replay() {
+                Some(replay_key) => {
+                    let known = self.cfg.keymap.known_bindings(self.state.mode);
+                    result = self.chord.feed(&replay_key, &known);
+                    current_key = replay_key;
+                }
+                None => return Ok(false),
             }
         }
     }
@@ -546,6 +561,16 @@ impl App {
                 self.state.show_overlay(OverlayKind::Help);
             }
             Action::OpenCommandBar => effects.extend(self.open_command_bar()),
+            // Escape hatch (#156): the literal byte, not the bar.
+            Action::SendLiteralCtrlK => {
+                effects.extend(self.forward_to_session(&InputKey::ctrl_char('k')));
+            }
+            // Escape hatch (#158): the leader's own byte, built from the
+            // configured leader rather than a hardcoded key.
+            Action::SendLiteralLeader => {
+                let leader = self.cfg.leader.clone();
+                effects.extend(self.forward_to_session(&leader));
+            }
             Action::OpenSpawnModal => {
                 self.open_spawn_modal();
                 effects.push(Effect::LoadDraft);
@@ -2912,6 +2937,55 @@ mod tests {
         CtEvent::Key(crossterm::event::KeyEvent::new(code, mods))
     }
 
+    fn ctrl_key_event(c: char) -> CtEvent {
+        key_event(
+            crossterm::event::KeyCode::Char(c),
+            crossterm::event::KeyModifiers::CONTROL,
+        )
+    }
+
+    /// Drive a sequence of key events through an app in Insert mode with a
+    /// session attached, and report the app afterwards plus every chunk of
+    /// bytes that reached that session, in order.
+    async fn drive_insert_sequence(
+        section: &TuiSection,
+        events: &[CtEvent],
+    ) -> (App, Vec<Vec<u8>>) {
+        use crate::session_task::{SessionHandle, SessionState};
+        use std::sync::atomic::{AtomicU64, AtomicU8};
+        use std::sync::{Arc, Mutex};
+        use tokio::sync::mpsc;
+
+        let sid = Uuid::from_u128(41);
+        let mut app = App::new(
+            TuiConfig::load(section).unwrap(),
+            CatalogStore::default(),
+            DaemonClient::new("http://127.0.0.1:7070"),
+            DaemonLink::default(),
+        );
+        let (tx, mut rx) = mpsc::channel(8);
+        app.emulators.insert(
+            sid,
+            SessionHandle {
+                tx,
+                screen: Arc::new(Mutex::new(vt100::Parser::new(24, 80, 0))),
+                state: Arc::new(AtomicU8::new(SessionState::Live as u8)),
+                revision: Arc::new(AtomicU64::new(0)),
+            },
+        );
+        app.state.attach_to_focused(sid);
+        app.state.mode = Mode::Insert;
+        app.state.focus = Focus::Pane;
+        for ev in events {
+            app.handle_event(ev.clone()).await.unwrap();
+        }
+        let mut sent = Vec::new();
+        while let Ok(SessionInput::Bytes(bytes)) = rx.try_recv() {
+            sent.push(bytes);
+        }
+        (app, sent)
+    }
+
     /// Escape belongs to the session: full-screen apps (vim, Claude Code) read
     /// it constantly, so no Insert-mode default may swallow it. The leader is
     /// the way back to the sidebar.
@@ -2930,19 +3004,120 @@ mod tests {
 
     /// `Noop` suppresses a binding, and in Insert mode a key with no binding is
     /// the session's — so binding a key to `Noop` hands it to the pty.
+    ///
+    /// Uses `ctrl-x`, not the leader: the leader is also a chord prefix
+    /// (#156), so a single fed keystroke on it resolves as `Pending`, not
+    /// `Resolved` — a different mechanism, covered separately below.
     #[tokio::test]
     async fn a_noop_insert_binding_forwards_the_key_to_the_session() {
         let mut section = TuiSection::default();
-        section.keymap_insert.insert("ctrl-a".into(), "Noop".into());
+        section.keymap_insert.insert("ctrl-x".into(), "Noop".into());
         let sent = bytes_sent_for(
             &section,
             key_event(
-                crossterm::event::KeyCode::Char('a'),
+                crossterm::event::KeyCode::Char('x'),
                 crossterm::event::KeyModifiers::CONTROL,
             ),
         )
         .await;
-        assert_eq!(sent, Some(vec![0x01]));
+        assert_eq!(sent, Some(vec![0x18]));
+    }
+
+    /// Leader then `ctrl-k` sends the literal byte and never opens the bar
+    /// (#156) — the default leader, `ctrl-a`.
+    #[tokio::test]
+    async fn leader_then_ctrl_k_sends_the_literal_byte_and_does_not_open_the_bar() {
+        let (app, sent) = drive_insert_sequence(
+            &TuiSection::default(),
+            &[ctrl_key_event('a'), ctrl_key_event('k')],
+        )
+        .await;
+        assert_eq!(sent, vec![vec![0x0b]]);
+        assert_eq!(app.state.overlay(), None);
+        assert_eq!(app.state.mode, Mode::Insert, "still in Insert, not left");
+    }
+
+    /// The escape hatch is built from the configured leader, not a hardcoded
+    /// `ctrl-a` — rebinding `[tui].leader` rebinds it too (#156).
+    #[tokio::test]
+    async fn a_rebound_leader_still_reaches_the_literal_ctrl_k_escape() {
+        let section = TuiSection {
+            leader: Some("ctrl-b".into()),
+            ..Default::default()
+        };
+        let (app, sent) =
+            drive_insert_sequence(&section, &[ctrl_key_event('b'), ctrl_key_event('k')]).await;
+        assert_eq!(sent, vec![vec![0x0b]]);
+        assert_eq!(app.state.overlay(), None);
+    }
+
+    /// Leader alone, followed by an ordinary key, still leaves Insert mode —
+    /// the escape hatch chord doesn't cost the leader its existing meaning
+    /// (#156).
+    #[tokio::test]
+    async fn leader_alone_still_leaves_insert_when_followed_by_another_key() {
+        let (app, sent) = drive_insert_sequence(
+            &TuiSection::default(),
+            &[
+                ctrl_key_event('a'),
+                key_event(
+                    crossterm::event::KeyCode::Char('j'),
+                    crossterm::event::KeyModifiers::NONE,
+                ),
+            ],
+        )
+        .await;
+        assert!(
+            sent.is_empty(),
+            "no bytes for the leader chord itself: {sent:?}"
+        );
+        assert_eq!(app.state.mode, Mode::Normal, "leader still leaves Insert");
+    }
+
+    /// Leader pressed twice sends one literal leader byte, tmux-style, and
+    /// clears the pending chord rather than leaving Insert (#158) — the
+    /// default leader, `ctrl-a`.
+    #[tokio::test]
+    async fn leader_twice_sends_the_literal_leader_byte_and_stays_in_insert() {
+        let (app, sent) = drive_insert_sequence(
+            &TuiSection::default(),
+            &[ctrl_key_event('a'), ctrl_key_event('a')],
+        )
+        .await;
+        assert_eq!(sent, vec![vec![0x01]]);
+        assert_eq!(app.state.mode, Mode::Insert, "still in Insert, not left");
+    }
+
+    /// The escape hatch is built from the configured leader, not a hardcoded
+    /// `ctrl-a` — rebinding `[tui].leader` rebinds it too (#158).
+    #[tokio::test]
+    async fn a_rebound_leader_still_reaches_the_literal_leader_escape() {
+        let section = TuiSection {
+            leader: Some("ctrl-b".into()),
+            ..Default::default()
+        };
+        let (app, sent) =
+            drive_insert_sequence(&section, &[ctrl_key_event('b'), ctrl_key_event('b')]).await;
+        assert_eq!(sent, vec![vec![0x02]]);
+        assert_eq!(app.state.mode, Mode::Insert);
+    }
+
+    /// After the literal-leader escape fires, the chord is gone — a further
+    /// leader press starts a fresh chord rather than resolving as a
+    /// three-deep sequence (#158).
+    #[tokio::test]
+    async fn leader_twice_then_ctrl_k_is_a_fresh_chord() {
+        let (_app, sent) = drive_insert_sequence(
+            &TuiSection::default(),
+            &[
+                ctrl_key_event('a'),
+                ctrl_key_event('a'),
+                ctrl_key_event('a'),
+                ctrl_key_event('k'),
+            ],
+        )
+        .await;
+        assert_eq!(sent, vec![vec![0x01], vec![0x0b]]);
     }
 
     #[test]

crates/maestro-tui/src/config.rs

@@ -146,6 +146,25 @@ impl TuiConfig {
         keymap
             .set(Mode::Insert, &leader.canonical(), "LeaveInsert")
             .expect("leader canonical form is valid by construction");
+        // Leader, ctrl-k → the literal-Ctrl-K escape hatch (#156), built from
+        // the same leader spec so rebinding leader rebinds this chord too.
+        keymap
+            .set(
+                Mode::Insert,
+                &format!("{} ctrl-k", leader.canonical()),
+                "SendLiteralCtrlK",
+            )
+            .expect("leader canonical form is valid by construction");
+        // Leader, leader → the literal-leader escape hatch (#158), tmux-style:
+        // pressing it twice sends the leader byte itself. Built from the same
+        // leader spec, so rebinding leader rebinds this chord too.
+        keymap
+            .set(
+                Mode::Insert,
+                &format!("{} {}", leader.canonical(), leader.canonical()),
+                "SendLiteralLeader",
+            )
+            .expect("leader canonical form is valid by construction");
 
         for (input, action) in &section.keymap_normal {
             keymap.set(Mode::Normal, input, action).map_err(|source| {
@@ -278,6 +297,60 @@ mod tests {
         assert_eq!(cfg.keymap.resolve(Mode::Insert, "ctrl-a"), None);
     }
 
+    /// The literal-Ctrl-K escape hatch (#156) is chorded off the default
+    /// leader, `ctrl-a ctrl-k` — not the command bar.
+    #[test]
+    fn default_leader_escapes_a_literal_ctrl_k() {
+        let cfg = TuiConfig::load(&TuiSection::default()).unwrap();
+        assert_eq!(
+            cfg.keymap.resolve(Mode::Insert, "ctrl-a ctrl-k"),
+            Some(Action::SendLiteralCtrlK),
+        );
+    }
+
+    /// Rebinding the leader must rebind the literal-Ctrl-K chord with it, not
+    /// just the Insert escape — proving the chord is built from the
+    /// configured leader rather than a hardcoded `ctrl-a`.
+    #[test]
+    fn rebinding_leader_moves_the_literal_ctrl_k_chord() {
+        let mut section = TuiSection::default();
+        section.leader = Some("ctrl-b".into());
+        let cfg = TuiConfig::load(&section).unwrap();
+        assert_eq!(
+            cfg.keymap.resolve(Mode::Insert, "ctrl-b ctrl-k"),
+            Some(Action::SendLiteralCtrlK),
+        );
+        // The old leader's chord is gone along with its Insert escape.
+        assert_eq!(cfg.keymap.resolve(Mode::Insert, "ctrl-a ctrl-k"), None);
+    }
+
+    /// The literal-leader escape hatch (#158) is chorded off the leader
+    /// doubled: `ctrl-a ctrl-a` — tmux's doubled-prefix resolution.
+    #[test]
+    fn default_leader_escapes_a_literal_leader() {
+        let cfg = TuiConfig::load(&TuiSection::default()).unwrap();
+        assert_eq!(
+            cfg.keymap.resolve(Mode::Insert, "ctrl-a ctrl-a"),
+            Some(Action::SendLiteralLeader),
+        );
+    }
+
+    /// Rebinding the leader must rebind the literal-leader chord with it,
+    /// not just the Insert escape and the Ctrl-K chord — proving it too is
+    /// built from the configured leader rather than a hardcoded `ctrl-a`.
+    #[test]
+    fn rebinding_leader_moves_the_literal_leader_chord() {
+        let mut section = TuiSection::default();
+        section.leader = Some("ctrl-b".into());
+        let cfg = TuiConfig::load(&section).unwrap();
+        assert_eq!(
+            cfg.keymap.resolve(Mode::Insert, "ctrl-b ctrl-b"),
+            Some(Action::SendLiteralLeader),
+        );
+        // The old leader's chord is gone along with the rest of its bindings.
+        assert_eq!(cfg.keymap.resolve(Mode::Insert, "ctrl-a ctrl-a"), None);
+    }
+
     #[test]
     fn user_normal_override_replaces_default() {
         let mut section = TuiSection::default();

crates/maestro-tui/src/input.rs

@@ -387,6 +387,9 @@ pub struct ChordState {
     held: Vec<String>,
     last_press: Option<Instant>,
     timeout: Duration,
+    /// A key bumped out of an abandoned chord (see [`Self::feed`]), waiting
+    /// to be replayed as a fresh keystroke by the caller.
+    replay: Option<InputKey>,
 }
 
 impl ChordState {
@@ -395,6 +398,7 @@ impl ChordState {
             held: Vec::new(),
             last_press: None,
             timeout,
+            replay: None,
         }
     }
 
@@ -404,6 +408,13 @@ impl ChordState {
     ///   binding; wait for the next key.
     /// * `Resolved(s)` — `s` is the canonical chord (or single key) to look
     ///   up in the keymap. The held buffer is cleared.
+    ///
+    /// A held prefix that is itself directly bound (e.g. a leader key bound
+    /// alone as well as chorded, like `ctrl-a` and `ctrl-a ctrl-k`) resolves
+    /// to that binding the moment the next key fails to extend it, rather
+    /// than swallowing the held key and losing its meaning — the new key
+    /// never belonged to the chord and is handed back via [`Self::take_replay`]
+    /// so the caller can process it as its own keystroke.
     pub fn feed(&mut self, key: &InputKey, known_bindings: &HashSet<String>) -> ChordResult {
         if let Some(t) = self.last_press {
             if t.elapsed() > self.timeout {
@@ -428,11 +439,31 @@ impl ChordState {
 
         if is_prefix {
             self.held.push(key_s);
-            ChordResult::Pending
-        } else {
-            self.held.clear();
-            ChordResult::Resolved(candidate)
+            return ChordResult::Pending;
         }
+
+        if known_bindings.contains(&candidate) {
+            self.held.clear();
+            return ChordResult::Resolved(candidate);
+        }
+
+        if !self.held.is_empty() {
+            let held_str = self.held.join(" ");
+            self.held.clear();
+            if known_bindings.contains(&held_str) {
+                self.replay = Some(key.clone());
+                return ChordResult::Resolved(held_str);
+            }
+        }
+
+        ChordResult::Resolved(candidate)
+    }
+
+    /// Take the key bumped out of an abandoned chord by the last [`Self::feed`]
+    /// call, if any. The caller feeds it through again as a brand new
+    /// keystroke.
+    pub fn take_replay(&mut self) -> Option<InputKey> {
+        self.replay.take()
     }
 }
 
@@ -733,6 +764,41 @@ mod tests {
         assert_eq!(r, ChordResult::Resolved("g x".into()));
     }
 
+    /// A key bound both alone and as a chord prefix (the leader: `ctrl-a` and
+    /// `ctrl-a ctrl-k`) must still fire its own binding when the next key
+    /// doesn't complete the chord — the held key's meaning isn't lost, and
+    /// the new key comes back via `take_replay` for the caller to process on
+    /// its own (#156).
+    #[test]
+    fn a_bound_prefix_resolves_itself_and_replays_the_breaking_key() {
+        let mut chord = ChordState::new(Duration::from_secs(10));
+        let known: HashSet<String> = ["ctrl-a".into(), "ctrl-a ctrl-k".into()]
+            .into_iter()
+            .collect();
+
+        let r = chord.feed(&InputKey::ctrl_char('a'), &known);
+        assert_eq!(r, ChordResult::Pending);
+
+        let r = chord.feed(&InputKey::char('j'), &known);
+        assert_eq!(r, ChordResult::Resolved("ctrl-a".into()));
+        assert_eq!(chord.take_replay(), Some(InputKey::char('j')));
+    }
+
+    /// The full chord still resolves normally when the next key completes
+    /// it — no replay, no early fire of the shorter binding.
+    #[test]
+    fn a_completed_chord_off_a_bound_prefix_has_no_replay() {
+        let mut chord = ChordState::new(Duration::from_secs(10));
+        let known: HashSet<String> = ["ctrl-a".into(), "ctrl-a ctrl-k".into()]
+            .into_iter()
+            .collect();
+
+        chord.feed(&InputKey::ctrl_char('a'), &known);
+        let r = chord.feed(&InputKey::ctrl_char('k'), &known);
+        assert_eq!(r, ChordResult::Resolved("ctrl-a ctrl-k".into()));
+        assert_eq!(chord.take_replay(), None);
+    }
+
     #[test]
     fn chord_state_lone_key_resolves_immediately() {
         let mut chord = ChordState::new(Duration::from_secs(10));

docs/COMMAND-BAR.md

@@ -45,8 +45,15 @@ 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.
+The leader itself needs the same kind of way back: holding it consumes every
+press, on both clients, even before anything is bound behind it. Pressing it
+twice — `ctrl-a ctrl-a` by default — sends one literal leader byte to the
+focused pane and clears the pending chord, the way tmux resolves a doubled
+prefix key. This chord is also built from the configured leader, so a
+rebound leader carries its own escape hatch with it.
+
+Only Ctrl-K and the leader itself get an escape hatch. No other control
+character is intercepted, so none of them needs one.
 
 ### Focus round-trip
 

docs/PREVIEW.md

@@ -46,7 +46,7 @@ Web client (`--preview` and friends in `web/src/styles.css`):
 | 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. |
+| The sidebar row being previewed | Filled with the preview hue, over whatever open state the row already had — but the row of the session already showing in the pane keeps its accent fill, since previewing it changes nothing on screen. |
 | 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

@@ -189,7 +189,7 @@ furthest down wins the paint.
 | 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) |
+| Previewing (`docs/PREVIEW.md`), unless that row is the one showing in the pane | `--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

web/src/commands.test.ts

@@ -6,12 +6,14 @@ import {
   CommandSet,
   DEFAULT_LEADER,
   canonicalizeKey,
+  controlByte,
   defineCommands,
   isBarTypingTarget,
   isTerminalTextarea,
   isTypingTarget,
   keyCaps,
   publishedCommands,
+  type Command,
 } from "./commands.js";
 
 function key(k: string, init: KeyboardEventInit = {}): KeyboardEvent {
@@ -307,3 +309,62 @@ describe("ctrl-k over a focused pane (#152)", () => {
     expect(spec?.keys).toEqual([`${DEFAULT_LEADER} ctrl-k`]);
   });
 });
+
+describe("leader pressed twice (#158)", () => {
+  it("sends one literal leader byte and clears the pending chord", () => {
+    const literal = vi.fn();
+    const run = vi.fn();
+    const set = new CommandSet(
+      defineCommands({ "pane.literalLeader": literal, "spawn.open": run }),
+      { leader: DEFAULT_LEADER },
+    );
+    const target = el('<textarea class="xterm-helper-textarea"></textarea>');
+    expect(pressOn(set, target, "a", { ctrlKey: true })).toBe(true);
+    expect(pressOn(set, target, "a", { ctrlKey: true })).toBe(true);
+    expect(literal).toHaveBeenCalledTimes(1);
+    // The chord is cleared, not still held: the next key is ordinary again.
+    expect(set.handle(key("n"))).toBe(true);
+    expect(run).toHaveBeenCalledTimes(1);
+  });
+
+  it("binds the escape hatch behind the default leader", () => {
+    const spec = COMMAND_SPECS.find((s) => s.id === "pane.literalLeader");
+    expect(spec?.keys).toEqual([`${DEFAULT_LEADER} ${DEFAULT_LEADER}`]);
+  });
+
+  // Not just the default: the chord is resolved from whatever leader this
+  // set was constructed with, so a rebound leader carries the escape hatch
+  // with it — the same proof #156 wrote for the TUI. The web has no config
+  // for this yet (#159), but the mechanism must not be hardcoded to ctrl-a.
+  it("follows a rebound leader, not just the default", () => {
+    const literal = vi.fn();
+    const rebound: Command = {
+      id: "pane.literalLeader",
+      label: "Send a literal leader key to the pane",
+      group: "Pane",
+      scope: "global",
+      keys: ["ctrl-b ctrl-b"],
+      run: literal,
+    };
+    const set = new CommandSet([rebound], { leader: "ctrl-b" });
+    const target = el('<textarea class="xterm-helper-textarea"></textarea>');
+    expect(pressOn(set, target, "b", { ctrlKey: true })).toBe(true);
+    expect(pressOn(set, target, "b", { ctrlKey: true })).toBe(true);
+    expect(literal).toHaveBeenCalledTimes(1);
+    // The old leader no longer does anything special.
+    expect(pressOn(set, target, "a", { ctrlKey: true })).toBe(false);
+  });
+});
+
+describe("controlByte", () => {
+  it("computes the raw control byte from a plain ctrl chord", () => {
+    expect(controlByte("ctrl-a")).toBe("\x01");
+    expect(controlByte("ctrl-k")).toBe("\x0b");
+  });
+
+  it("rejects anything that isn't a single plain ctrl chord", () => {
+    expect(() => controlByte("ctrl-shift-a")).toThrow();
+    expect(() => controlByte("a")).toThrow();
+    expect(() => controlByte("ctrl-a ctrl-a")).toThrow();
+  });
+});

web/src/commands.ts

@@ -67,6 +67,13 @@ export const COMMAND_SPECS: readonly CommandSpec[] = [
     keys: [`${DEFAULT_LEADER} ctrl-k`],
     scope: "global",
   },
+  {
+    id: "pane.literalLeader",
+    label: "Send a literal leader key to the pane",
+    group: "Pane",
+    keys: [`${DEFAULT_LEADER} ${DEFAULT_LEADER}`],
+    scope: "global",
+  },
   {
     id: "focus.toggle",
     label: "Move the keyboard between the session list and the pane",
@@ -227,6 +234,15 @@ export function canonicalizeKey(e: KeyboardEvent): string | null {
   return out + e.key.toLowerCase();
 }
 
+/** The raw control byte for a canonical `ctrl-<letter>` chord — `ctrl-a` is
+ *  `0x01` — mirroring the TUI's `encode_key`. Built from the chord string
+ *  itself so a different leader sends its own byte, not a hardcoded one. */
+export function controlByte(chord: string): string {
+  const m = /^ctrl-([a-z])$/.exec(chord);
+  if (!m) throw new Error(`not a plain ctrl chord: ${chord}`);
+  return String.fromCharCode(m[1].charCodeAt(0) - 96);
+}
+
 const MOD_PREFIX = /^(ctrl|alt|meta|shift)-/;
 
 /** True when a chord carries a modifier or more than one key. Plain single-key

web/src/main.ts

@@ -7,7 +7,7 @@ import { ConnectionPool } from "./connections.js";
 import { installDrawer, installDrawerSwipe, requestToggleDrawer } from "./drawer.js";
 import { installHudKeybind } from "./debug.js";
 import { installHelpKeybind, isHelpOpen } from "./help.js";
-import { CommandSet, DEFAULT_LEADER, defineCommands, isBarTypingTarget } from "./commands.js";
+import { CommandSet, DEFAULT_LEADER, controlByte, defineCommands, isBarTypingTarget } from "./commands.js";
 import { isCommandBarOpen, openCommandBar, SPAWN_DIRECTORY_EVENT } from "./commandBar.js";
 import { DaemonLink } from "./daemonLink.js";
 import { CatalogStore } from "./events.js";
@@ -456,6 +456,11 @@ const focusKeys = new CommandSet(
     // 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"),
+    // The leader itself, pressed twice, tmux-style: sends one literal leader
+    // byte and clears the pending chord instead of resolving as a dead chord
+    // (docs/COMMAND-BAR.md, #158). Built from `DEFAULT_LEADER`, not a
+    // hardcoded byte, so a different leader would send its own.
+    "pane.literalLeader": () => pool.sendToFocused(controlByte(DEFAULT_LEADER)),
   }),
   { leader: DEFAULT_LEADER },
 );

web/src/styles.css

@@ -1202,8 +1202,10 @@ textarea {
 }
 
 /* 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) {
+   session that is already open still reads as provisional — except the session
+   already mounted in the pane (tier 4). Previewing that one changes nothing on
+   screen, so its accent stays put instead of blinking out under the pointer. */
+.tree-leaf:where(.is-previewing):where(:not(.is-active)) {
   background: var(--preview-tint);
 }