feat: major dashboard & waiter PWA overhaul

- Manager dashboard: replaced monolithic DashboardTab/OperationsPage with new
  DashboardPage; added OrderDetailModal, ShiftDetailModal, DeleteConfirmModal,
  PaymentMethodModal; updated Sidebar routing and App navigation
- Reports: reworked WorkDaySummary, OrderHistory, ShiftsOverview with detail modals
- Backend routers: extended orders, reports, shifts, products, business_day endpoints;
  updated cloud_sync service
- Waiter PWA: refreshed app icons, improved ConnectionLostModal UX, updated
  TableCard, SSEContext, connectionStore; added useProductCache hook; vite config tweaks

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

waiter_pwa/package.json

@@ -10,6 +10,7 @@
     "preview": "vite preview"
   },
   "dependencies": {
+    "@tanstack/react-query": "^5.100.11",
     "axios": "^1.15.1",
     "dexie": "^4.4.2",
     "react": "^19.2.5",