Move the keybind router out of Shell into a reusable createDispatcher
in @/utils/dispatch, covering tabs (digits 1-6, [/]), h/l depth
drill/pop + fixed-pane swipe, modes, audio transport, quit/help, and
command, delegating pane/list actions over the nav.action event bus.
Shell now renders the active page full-width with a bottom status bar
carrying the tab strip; the old sidebar pane and its leftover sidebar
action handling are removed. Adds tests covering the dispatcher's
routing behavior.
- Remove the left tab sidebar containing tab labels and now-playing
- Render tabs as compact labels in the command bar row instead
- Move now-playing display next to the selection count in the status bar
- All tabs remain functional; clicking a tab label switches the active tab
- Extract navigation state and logic into navigation-store.ts for
testability and separation of concerns
- NavigationContext now only wraps the store as a Solid provider
- Remove SIDEBAR_PANE from the model; depth-tabs have a single
focusable content pane (center/current column)
- Split LayerGraph and page imports into layer-graph.ts so the
navigation utils stay free of JSX (unit-testable)
- Update Shell keybind dispatch: remove sidebar pane handling,
simplify swipe to fixed-pane tabs only, clarify depth-tab h/l
- Add nav-model.test.ts covering depth stack, tab/pane focus, and
selection semantics
