test: add command palette and fuzzy match tests

Tests for CommandPalette component (rendering, filtering, keyboard
navigation, grouped results, shortcuts display), useCommandRegistry
hook (contextual actions, archive toggle, git availability), fuzzyMatch
utility, and Cmd+K shortcut.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/hooks/useAppKeyboard.test.ts

@@ -17,6 +17,7 @@ function fireKey(key: string, mods: { altKey?: boolean; metaKey?: boolean; ctrlK
 function makeActions() {
   return {
     onQuickOpen: vi.fn(),
+    onCommandPalette: vi.fn(),
     onCreateNote: vi.fn(),
     onSave: vi.fn(),
     onOpenSettings: vi.fn(),
@@ -86,4 +87,11 @@ describe('useAppKeyboard', () => {
     fireKey('4', { altKey: true })
     expect(actions.onSetViewMode).not.toHaveBeenCalled()
   })
+
+  it('Cmd+K triggers command palette', () => {
+    const actions = makeActions()
+    renderHook(() => useAppKeyboard(actions))
+    fireKey('k', { metaKey: true })
+    expect(actions.onCommandPalette).toHaveBeenCalled()
+  })
 })