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/loadingReducer.dart

@@ -1,5 +1,6 @@
 import 'actions.dart';
-bool loadingReducer(isLoading, action) {
+
+bool loadingReducer(bool isLoading, dynamic action) {
   if (action is FetchYourLocationsAction) return true;
   return isLoading;
-}
+}