fix: resolve 78 strict analysis errors with explicit type annotations

Implemented systematic type safety improvements across the codebase to eliminate all 78 strict analysis errors:

## Phase 1: Quick Wins (Redux & Model Fixes)
- Added explicit type annotations to Redux reducer parameters
- Fixed copyWith() methods in FireNotification and YourLocation models with proper nullable types
- Fixed BasicLocation field initializers with type casts (num to double)
- Fixed context parameter inference in IntroPage and PrivacyPage
- Regenerated .g.dart files with build_runner

## Phase 2: JSON Deserialization
- Fixed homePage.dart Firebase message parameter casting (9 errors)
- Fixed firesApi.dart JSON parsing:
  - Added explicit casts for num to double/int conversions
  - Fixed array iteration with proper List<dynamic> casting
  - Added return type annotation to objectIdFromJson()
  - Fixed nested JSON access in getMonitoredAreas()
- Fixed globalFiresBottomStats.dart dynamic to int/String casting
- Fixed locationUtils.dart string assignments

## Phase 3: Config & Redux Middleware
- Fixed mainCommon.dart config map access with explicit String casts
- Fixed mainProd.dart Sentry DSN casting
- Fixed fetchDataMiddleware.dart:
  - Added Store<AppState>, String type annotations to createUser()
  - Added Function(YourLocation) type to subscribeViaApi callback
  - Added Exception type to catchError handler
- Fixed fireMapReducer.dart restoreStatusAfterSave parameter type
- Fixed persist files with Map<String, dynamic> type annotations

## Phase 4: Edge Cases
- Fixed slider.dart method return types (Widget sizeText, Widget warningText)
- Fixed mainDrawer.dart Key? parameter type annotation

Result: 78 errors → 0 errors

lib/redux/fetchDataMiddleware.dart

@@ -185,7 +185,7 @@ void fetchDataMiddleware(Store<AppState> store, action, NextDispatcher next) {
         final Completer<Null>? completer = action.refreshCallback;
         completer?.complete(null);
       });
-    }).catchError((onError) {
+    }).catchError((Exception onError) {
       // If it fails, dispatch a failure action. The reducer will
       // update the state with the error.
       store.dispatch(new FetchYourLocationsFailedAction(onError));
@@ -261,7 +261,8 @@ void unsubsViaApi(Store<AppState> store, ObjectId id, onUnsubs) {
   });
 }
 
-void subscribeViaApi(Store<AppState> store, YourLocation loc, onSubs) {
+void subscribeViaApi(
+    Store<AppState> store, YourLocation loc, Function(YourLocation) onSubs) {
   api.subscribe(store.state, loc).then((subsId) {
     YourLocation sub = loc;
     // if (loc.id != subsId) {
@@ -272,7 +273,7 @@ void subscribeViaApi(Store<AppState> store, YourLocation loc, onSubs) {
   });
 }
 
-void createUser(store, lang, token) {
+void createUser(Store<AppState> store, String lang, String token) {
   assert(token != null, "User lang is null");
   assert(token != null, "User mobile token is null");
   api.createUser(store.state, token, lang).then((userId) {