macOS reserves cmd+` for window cycling, so the keydown never reached the
renderer and profile.default never fired. Move it to ⌥⌘0 — the "0 slot" of
the ⌘⌥-digit profile range — which is unreserved and fits the scheme.
Add rebindable actions for the high-frequency gaps: focus composer, open
model picker, next/prev session, search sessions (⌘⇧F), show files/
terminal tab, and nav→artifacts. Reconcile the duplicate Shift+N new-
session listener into session.new's defaults, and surface the remaining
context-local shortcuts (⌘↵ steer, ⌘L terminal selection, ⌘W close
preview) as read-only rows so the panel is the honest source of truth.
Add a central keybind registry + nanostore so desktop hotkeys are
discoverable and user-rebindable. A titlebar ⌨ button (and ⌘/) opens a
collapsible map grouped by Composer (read-only) / Profiles / Session /
Navigation / View; click any chip to capture a new combo. Overrides
persist to localStorage as a delta against shipped defaults, so future
default changes aren't shadowed by a stored snapshot.
Migrates the previously scattered inline listeners (palette, command
center, new session, sidebar, theme) into the registry, and adds profile
switch/cycle/create + default-profile hotkeys.
