refactor(web): add Redux state management and centralised routing

- Replace inline BrowserRouter with createBrowserRouter and lazy-loaded pages
- Add Redux store with auth-slice (token management) and redux-persist
- Create RequireAuth guard using Redux state via isAuthenticated selector
- Wire Layout logout to dispatch setToken("") clearing persisted auth
- Add ErrorPage component for route error handling
- Add EmptyLayout for unauthenticated pages
- Add VITE_REDUX_STORAGE env var for storage selection

web/package.json

@@ -14,12 +14,16 @@
     "@emotion/styled": "^11.14.1",
     "@mui/icons-material": "^9.2.0",
     "@mui/material": "^9.2.0",
+    "@reduxjs/toolkit": "^2.12.0",
     "@tailwindcss/vite": "^4.3.2",
     "axios": "^1.18.1",
     "dayjs": "^1.11.21",
     "react": "^19.2.7",
     "react-dom": "^19.2.7",
+    "react-redux": "^9.3.0",
+    "react-router": "^8.1.0",
     "react-router-dom": "^7.18.1",
+    "redux-persist": "^6.0.0",
     "tailwindcss": "^4.3.2"
   },
   "devDependencies": {