Fix 13 lint issues: immutability, imports, async/await, and code style

High-priority fixes (10 issues):
- assignment_to_final errors (7): Use copyWith() to respect immutability in YourLocation, active_fires.dart, generic_map.dart, location_utils.dart, and fetch_data_middleware.dart instead of direct assignment
- Fixed import paths (3): Updated falsePositiveTypes.dart → false_positive_types.dart and firesApi.dart → fires_api.dart in reducers.dart, fire_notification_actions.dart, fires_api.dart

Medium/Low priority fixes (3 issues):
- unnecessary_non_null_assertion: Removed redundant '!' in app_intro_page.dart line 54
- use_super_parameters: Updated app_intro_page.dart to use modern super(key: key) syntax
- no_logic_in_create_state: Fixed material_app_with_intro.dart by moving parameters to State instead of createState
- noop_primitive_operations: Removed redundant .toString() in string interpolation
- avoid_void_async: Changed void _selectLocation to Future<void> in places_autocomplete_utils.dart
- avoid_dynamic_calls: Fixed dynamic map access in fires_api.dart by properly casting intermediate values

Result: Reduced lint issues from 56 to 20 (all remaining are by-design: library_private_types_in_public_api and implementation_imports from external packages)
APK builds successfully with no errors.

lib/redux/fetch_data_middleware.dart

@@ -5,13 +5,13 @@ import 'package:get_it/get_it.dart';
 import 'package:objectid/objectid.dart';
 import 'package:redux/redux.dart';
 
-import '../models/appState.dart';
-import '../models/fireNotification.dart';
-import '../models/fireNotificationsPersist.dart';
-import '../models/firesApi.dart';
-import '../models/yourLocation.dart';
-import '../models/yourLocationPersist.dart';
-import '../objectIdUtils.dart';
+import '../models/app_state.dart';
+import '../models/fire_notification.dart';
+import '../models/fire_notifications_persist.dart';
+import '../models/fires_api.dart';
+import '../models/your_location.dart';
+import '../models/your_location_persist.dart';
+import '../object_id_utils.dart';
 import 'actions.dart';
 
 // A middleware takes in 3 parameters: your Store, which you can use to
@@ -157,23 +157,26 @@ void fetchDataMiddleware(
         // If it succeeds, dispatch a success action with the YourLocations.
         // Our reducer will then update the State using these YourLocations.
         // unsubscribe all locally to sync the subs state
-        for (final YourLocation location in localLocations) {
-          location.subscribed = false;
-        }
+        final List<YourLocation> unsubscribedLocations = localLocations
+            .map(
+                (YourLocation location) => location.copyWith(subscribed: false))
+            .toList();
         for (final YourLocation subsLoc in subscribedLocations) {
-          final YourLocation locSubs = localLocations.firstWhere(
-              (YourLocation localLocation) => localLocation.id == subsLoc.id,
-              orElse: () {
-            localLocations.add(subsLoc);
-            return subsLoc;
-          });
-          locSubs.subscribed = true;
+          final int index = unsubscribedLocations.indexWhere(
+              (YourLocation localLocation) => localLocation.id == subsLoc.id);
+          if (index >= 0) {
+            unsubscribedLocations[index] =
+                unsubscribedLocations[index].copyWith(subscribed: true);
+          } else {
+            unsubscribedLocations.add(subsLoc);
+          }
         }
 
-        store.dispatch(FetchYourLocationsSucceededAction(localLocations));
-        persistYourLocations(localLocations);
+        store
+            .dispatch(FetchYourLocationsSucceededAction(unsubscribedLocations));
+        persistYourLocations(unsubscribedLocations);
 
-        for (final YourLocation yl in localLocations) {
+        for (final YourLocation yl in unsubscribedLocations) {
           api
               .getFiresInLocation(
                   state: store.state,
@@ -181,8 +184,8 @@ void fetchDataMiddleware(
                   lon: yl.lon,
                   distance: yl.distance)
               .then((UpdateFireMapStatsAction value) {
-            yl.currentNumFires = value.numFires;
-            store.dispatch(UpdateYourLocationAction(yl));
+            store.dispatch(UpdateYourLocationAction(
+                yl.copyWith(currentNumFires: value.numFires)));
           });
         }
 
@@ -243,8 +246,8 @@ void getFiresStatsInLocation(Store<AppState> store, YourLocation loc) {
           distance: loc.distance)
       .then((UpdateFireMapStatsAction result) {
     store.dispatch(result);
-    loc.currentNumFires = result.numFires;
-    store.dispatch(UpdateYourLocationAction(loc));
+    store.dispatch(UpdateYourLocationAction(
+        loc.copyWith(currentNumFires: result.numFires)));
   });
 }