feat: complete UI/UX overhaul - dashboard unification, calendar UX, mobile optimization

- Dashboard redesign as command center with filters, quick actions, inline approve/reject
- Reusable components: BookingRow, BookingFilters, ActionMenu, BookingPreviewModal, BookingEditModal
- Calendar: drag & drop reschedule, eventClick preview modal, grid/list toggle
- Mobile: segmented control bookings/calendar toggle, compact pills, responsive layout
- Collapsible filters with active count badge
- Smart menu positioning with Teleport
- Calendar/list bidirectional data sync
- Navigation: unified History page, removed AdminPending
- Google Calendar OAuth integration
- Dark mode contrast improvements, breadcrumb navigation
- useLocalStorage composable for state persistence

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

frontend/package.json

@@ -13,6 +13,7 @@
     "@fullcalendar/core": "^6.1.0",
     "@fullcalendar/daygrid": "^6.1.0",
     "@fullcalendar/interaction": "^6.1.0",
+    "@fullcalendar/list": "^6.1.20",
     "@fullcalendar/timegrid": "^6.1.0",
     "@fullcalendar/vue3": "^6.1.0",
     "axios": "^1.6.0",