M11: upstream sync (17 commits)

CLAUDE.md

@@ -160,6 +160,7 @@ The app has a **Debug** menu in the macOS menu bar (only in DEBUG builds). Use i
 - **Terminal find layering contract:** `SurfaceSearchOverlay` must be mounted from `GhosttySurfaceScrollView` in `Sources/GhosttyTerminalView.swift` (AppKit portal layer), not from SwiftUI panel containers such as `Sources/Panels/TerminalPanelView.swift`. Portal-hosted terminal views can sit above SwiftUI during split/workspace churn.
 - **Submodule safety:** When modifying a submodule (ghostty, vendor/bonsplit, etc.), always push the submodule commit to its remote `main` branch BEFORE committing the updated pointer in the parent repo. Never commit on a detached HEAD or temporary branch — the commit will be orphaned and lost. Verify with: `cd <submodule> && git merge-base --is-ancestor HEAD origin/main`.
 - **All user-facing strings must be localized.** Use `String(localized: "key.name", defaultValue: "English text")` for every string shown in the UI (labels, buttons, menus, dialogs, tooltips, error messages). Keys go in `Resources/Localizable.xcstrings` with translations for all supported languages (currently English and Japanese). Never use bare string literals in SwiftUI `Text()`, `Button()`, alert titles, etc.
+- **Shortcut policy:** Every new cmux-owned keyboard shortcut must be added to `KeyboardShortcutSettings`, visible/editable in Settings, supported in `~/.config/cmux/settings.json`, and documented in the keyboard shortcut and configuration docs.
 
 ## Test quality policy