Implement Redux Persist for state persistence across page reloads

- Install redux-persist package
- Configure persistReducer with whitelist (offline, activities, children)
- Exclude network slice from persistence (should be fresh on reload)
- Add PersistGate to ReduxProvider with loading indicator
- Configure serializableCheck to ignore persist actions
- Store state now persists to localStorage automatically

This fixes the issue where app state was lost on page reload, improving UX.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

maternal-web/store/store.ts

@@ -1,4 +1,7 @@
 import { configureStore, Middleware } from '@reduxjs/toolkit';
+import { persistStore, persistReducer, FLUSH, REHYDRATE, PAUSE, PERSIST, PURGE, REGISTER } from 'redux-persist';
+import storage from 'redux-persist/lib/storage'; // defaults to localStorage for web
+import { combineReducers } from '@reduxjs/toolkit';
 
 // Slices
 import offlineReducer from './slices/offlineSlice';
@@ -10,26 +13,41 @@ import networkReducer from './slices/networkSlice';
 import { offlineMiddleware } from './middleware/offlineMiddleware';
 import { syncMiddleware } from './middleware/syncMiddleware';
 
+// Persist configuration
+const persistConfig = {
+  key: 'root',
+  version: 1,
+  storage,
+  // Only persist these slices (exclude network status as it should be fresh on reload)
+  whitelist: ['offline', 'activities', 'children'],
+};
+
+const rootReducer = combineReducers({
+  offline: offlineReducer,
+  activities: activitiesReducer,
+  children: childrenReducer,
+  network: networkReducer,
+});
+
+const persistedReducer = persistReducer(persistConfig, rootReducer);
+
 export const store = configureStore({
-  reducer: {
-    offline: offlineReducer,
-    activities: activitiesReducer,
-    children: childrenReducer,
-    network: networkReducer,
-  },
+  reducer: persistedReducer,
   middleware: (getDefaultMiddleware) =>
     getDefaultMiddleware({
       serializableCheck: {
-        // Ignore these action types for serialization check
-        ignoredActions: ['persist/PERSIST', 'persist/REHYDRATE'],
+        // Ignore redux-persist action types
+        ignoredActions: [FLUSH, REHYDRATE, PAUSE, PERSIST, PURGE, REGISTER, 'persist/PERSIST', 'persist/REHYDRATE'],
         // Ignore these field paths in all actions
-        ignoredActionPaths: ['meta.arg', 'payload.timestamp'],
+        ignoredActionPaths: ['meta.arg', 'payload.timestamp', 'register'],
         // Ignore these paths in the state
-        ignoredPaths: ['items.dates'],
+        ignoredPaths: ['items.dates', 'register'],
       },
     }).concat(offlineMiddleware, syncMiddleware),
 });
 
+export const persistor = persistStore(store);
+
 // Infer the `RootState` and `AppDispatch` types from the store itself
 export type RootState = ReturnType<typeof store.getState>;
 export type AppDispatch = typeof store.dispatch;