docs(tiles): Ctrl+Shift+G inert while the Tiles setting is off is the owner's decision

The spec listed it as the default applied while the owner's answer was
pending. The owner has decided: with showTileGridButton off the chord is
inert and passes through like any unbound key; on, it toggles the grid.
Recorded as decision 6 in the spec (with a line under Gating), and as an
owner decision in CLAUDE.md and the invariants.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

docs/architecture-invariants.md

@@ -805,7 +805,7 @@ Further detail: with many sessions the horizontal strip stops being scannable, w
 
 ⚠️ **Selections.** The tile branch of `selectSession` sits right after its "already active" early return: a tiled id is FOCUSED (`_selectTiledSession`: no cleanup, replay, resize or main socket; the shared `_refreshSessionPanels`; only a user-initiated pick acknowledges the idle alert). A USER-initiated pick of a session that is not tiled leaves the grid for the single view, remembered (decision 1), and so does `leaveTiles` (a followed `#session=` link); an `auto` pick never collapses it. Whoever calls `closeTileGrid({ reselect: false })` and then selects must null `activeSessionId` first, or `_cleanupPreviousSession` saves the parked terminal's stale content as a snapshot. App-driven fallbacks pick a tile: `closeSession` captures the neighbouring tile BEFORE its await (like `wasActive`; the delete broadcast may already have removed the tile) and focuses it with `auto`; the `_onSessionDeleted` wrapper does the same for a delete from elsewhere, and leaves a close from this tab (`_closingSessions`) to `closeSession`. Ctrl+Tab and Alt+[ ] cycle the tiles. A popped-out (detached) session leaves the grid. Moving focus off a zoomed tile restores the grid (tmux `select-pane`); an automatic zoom (window too small for the minimum tile) follows focus instead.
 
-⚠️ **Chords.** `toggle-tile-grid` (Ctrl+Shift+G), `focus-tile-*` (Alt+Shift+Arrows), `zoom-tile` (Alt+Shift+Enter) and `remove-tile` (unbound) are registry entries kept OUT of `SHORTCUT_ACTIONS`: `tileShortcutFor` decides whether one applies (the toggle while the grid is open, or where one could open AND `showTileGridButton` is on; the rest only while it is open), the capture handler dispatches it, and the main terminal's and every tile's xterm key handler return false for it, for every event type and BEFORE the Shift+Enter gate (Alt+Shift+Enter would otherwise send `S-Enter`). Outside the grid the focus chords reach the terminal untouched.
+⚠️ **Chords.** `toggle-tile-grid` (Ctrl+Shift+G), `focus-tile-*` (Alt+Shift+Arrows), `zoom-tile` (Alt+Shift+Enter) and `remove-tile` (unbound) are registry entries kept OUT of `SHORTCUT_ACTIONS`: `tileShortcutFor` decides whether one applies (the toggle while the grid is open, or where one could open AND `showTileGridButton` is on, an owner decision: with the setting off the chord is inert and passes through like any unbound key; the rest only while it is open), the capture handler dispatches it, and the main terminal's and every tile's xterm key handler return false for it, for every event type and BEFORE the Shift+Enter gate (Alt+Shift+Enter would otherwise send `S-Enter`). Outside the grid the focus chords reach the terminal untouched.
 
 ⚠️ **Chrome.** The header is a fixed 24px sibling of the body, refreshed in place on every tab render (`_renderSessionTabsImmediate` wrapper), never by rewriting the tile (that would take its xterm along) and never growing (#464: the body holds the xterm). Header buttons stop pointerdown, so acting on an unfocused tile does not focus it. × removes the tile only; killing stays behind the session menu's Close session. The `needs` pulse animates `box-shadow` only. Dividers are their own 6px grid tracks (`gap: 0`), tiles placed explicitly; a drag uses pointer capture, reflows the affected tiles locally per animation frame and sends ONE `fit()` (one PTY resize) per affected tile at pointer-up; closing the grid or removing a tile mid-drag tears it down. A tab dragged onto a tile replaces it (or swaps two tiles); tiles and empty slots handle `dragover`/`drop` in the CAPTURE phase and stop it, because the drag carries the session id as text and xterm's helper textarea would type it into the PTY.
 

docs/tile-grid-plan.md

@@ -17,8 +17,8 @@ or settled a question the spec left open. The invariants as built are in
   edge-case row below cannot work without a server change. The tile shows the exit and
   points at Close session. A session with no PTY (`pid === null`) and a socket closed with
   4009 do get Attach. Restarting an exited agent in place is a follow-up.
-- **`Ctrl+Shift+G` follows `showTileGridButton`** (the applied default while the owner's
-  answer is pending): with the setting off the toggle chord is inert. A grid opened another
+- **`Ctrl+Shift+G` follows `showTileGridButton`** (decided by the owner, decision 6): with
+  the setting off the toggle chord is inert. A grid opened another
   way (Ctrl/Cmd+click, a dropped tab, "Open group as tiles") keeps all its chords.
 - **Dividers are grid tracks.** Each gap between columns and rows is its own 6px track (the
   grid gap is 0) and tiles are placed explicitly in reading order, which is also what the
@@ -258,6 +258,9 @@ against the live list without rebuilding tiles that are still alive.
   keeps the stored grid.
 - Hidden in solo windows (`body.solo-mode`).
 - `test/mobile-header-buttons-policy.test.ts` keeps it off phones.
+- The toggle chord follows the setting (decision 6): with `showTileGridButton`
+  off, `Ctrl+Shift+G` is inert and reaches the terminal like any unbound key; on,
+  it toggles the grid. A grid opened another way keeps all its chords.
 
 ## Components
 
@@ -862,6 +865,10 @@ exits green. Use the browser runner for those files and read the file count.
    default key (Ctrl+W is delete-word in every shell and agent CLI, and it
    killed sessions with no confirm); it stays bindable in App Settings →
    Shortcuts.
+6. **`Ctrl+Shift+G` with the Tiles setting off.** Decided by the owner: the
+   chord is inert while `showTileGridButton` is off (it passes through like any
+   unbound key) and toggles the grid while it is on, so one setting governs both
+   the button and the chord.
 
 ## Code anchors