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/models/app_state.g.dart

@@ -0,0 +1,41 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'app_state.dart';
+
+// **************************************************************************
+// JsonSerializableGenerator
+// **************************************************************************
+
+AppState _$AppStateFromJson(Map json) => $checkedCreate(
+      'AppState',
+      json,
+      ($checkedConvert) {
+        final val = AppState(
+          yourLocations: $checkedConvert(
+              'yourLocations',
+              (v) =>
+                  (v as List<dynamic>?)
+                      ?.map((e) => YourLocation.fromJson(
+                          Map<String, dynamic>.from(e as Map)))
+                      .toList() ??
+                  const <YourLocation>[]),
+          fireNotifications: $checkedConvert(
+              'fireNotifications',
+              (v) =>
+                  (v as List<dynamic>?)
+                      ?.map((e) => FireNotification.fromJson(
+                          Map<String, dynamic>.from(e as Map)))
+                      .toList() ??
+                  const <FireNotification>[]),
+          isLoading: $checkedConvert('isLoading', (v) => v as bool? ?? false),
+        );
+        return val;
+      },
+    );
+
+Map<String, dynamic> _$AppStateToJson(AppState instance) => <String, dynamic>{
+      'isLoading': instance.isLoading,
+      'yourLocations': instance.yourLocations.map((e) => e.toJson()).toList(),
+      'fireNotifications':
+          instance.fireNotifications.map((e) => e.toJson()).toList(),
+    };

lib/models/fire_notification.dart

@@ -2,7 +2,7 @@ import 'package:flutter/material.dart';
 import 'package:json_annotation/json_annotation.dart';
 import 'package:objectid/objectid.dart';
 
-import '../objectIdUtils.dart';
+import '../object_id_utils.dart';
 import '../utils/widget_utils.dart';
 
 part 'fire_notification.g.dart';

lib/models/fire_notification.g.dart

@@ -0,0 +1,38 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'fire_notification.dart';
+
+// **************************************************************************
+// JsonSerializableGenerator
+// **************************************************************************
+
+FireNotification _$FireNotificationFromJson(Map json) => $checkedCreate(
+      'FireNotification',
+      json,
+      ($checkedConvert) {
+        final val = FireNotification(
+          id: $checkedConvert('id', (v) => objectIdFromJson(v as String)),
+          lat: $checkedConvert('lat', (v) => (v as num).toDouble()),
+          lon: $checkedConvert('lon', (v) => (v as num).toDouble()),
+          description: $checkedConvert('description', (v) => v as String),
+          when: $checkedConvert('when', (v) => DateTime.parse(v as String)),
+          read: $checkedConvert('read', (v) => v as bool),
+          sealed: $checkedConvert('sealed', (v) => v as String),
+          subsId:
+              $checkedConvert('subsId', (v) => objectIdFromJson(v as String)),
+        );
+        return val;
+      },
+    );
+
+Map<String, dynamic> _$FireNotificationToJson(FireNotification instance) =>
+    <String, dynamic>{
+      'id': objectIdToJson(instance.id),
+      'lat': instance.lat,
+      'lon': instance.lon,
+      'description': instance.description,
+      'when': instance.when.toIso8601String(),
+      'sealed': instance.sealed,
+      'subsId': objectIdToJson(instance.subsId),
+      'read': instance.read,
+    };

lib/models/fires_api.dart

@@ -7,10 +7,10 @@ import 'package:flutter_map/flutter_map.dart';
 import 'package:latlong2/latlong.dart';
 
 import '../globals.dart' as globals;
-import '../objectIdUtils.dart';
+import '../object_id_utils.dart';
 import '../redux/actions.dart';
 import 'app_state.dart';
-import 'falsePositiveTypes.dart';
+import 'false_positive_types.dart';
 import 'your_location.dart';
 
 class FiresApi {
@@ -189,9 +189,12 @@ class FiresApi {
         final Map<String, dynamic> unionData =
             dataData['union'] as Map<String, dynamic>;
         final String unionValue = unionData['value'] as String;
+        final Map<String, dynamic> decodedJson =
+            json.decode(unionValue) as Map<String, dynamic>;
+        final Map<String, dynamic> geometry =
+            decodedJson['geometry'] as Map<String, dynamic>;
         final List<dynamic> multipolygon =
-            (json.decode(unionValue) as Map<String, dynamic>)['geometry']
-                ['coordinates'] as List<dynamic>;
+            geometry['coordinates'] as List<dynamic>;
         for (final dynamic polygonDynamic in multipolygon) {
           final List<dynamic> polygon = polygonDynamic as List<dynamic>;
           for (final dynamic holeDynamic in polygon) {

lib/models/your_location.dart

@@ -2,7 +2,7 @@ import 'package:json_annotation/json_annotation.dart';
 import 'package:meta/meta.dart';
 import 'package:objectid/objectid.dart';
 
-import '../objectIdUtils.dart';
+import '../object_id_utils.dart';
 
 part 'your_location.g.dart';
 

lib/models/your_location.g.dart

@@ -0,0 +1,38 @@
+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'your_location.dart';
+
+// **************************************************************************
+// JsonSerializableGenerator
+// **************************************************************************
+
+YourLocation _$YourLocationFromJson(Map json) => $checkedCreate(
+      'YourLocation',
+      json,
+      ($checkedConvert) {
+        final val = YourLocation(
+          id: $checkedConvert('id', (v) => objectIdFromJson(v as String)),
+          lat: $checkedConvert('lat', (v) => (v as num).toDouble()),
+          lon: $checkedConvert('lon', (v) => (v as num).toDouble()),
+          description:
+              $checkedConvert('description', (v) => v as String? ?? ''),
+          distance:
+              $checkedConvert('distance', (v) => (v as num?)?.toInt() ?? 10),
+          currentNumFires:
+              $checkedConvert('currentNumFires', (v) => (v as num?)?.toInt()),
+          subscribed: $checkedConvert('subscribed', (v) => v as bool? ?? false),
+        );
+        return val;
+      },
+    );
+
+Map<String, dynamic> _$YourLocationToJson(YourLocation instance) =>
+    <String, dynamic>{
+      'id': objectIdToJson(instance.id),
+      'lat': instance.lat,
+      'lon': instance.lon,
+      'description': instance.description,
+      'subscribed': instance.subscribed,
+      'distance': instance.distance,
+      'currentNumFires': instance.currentNumFires,
+    };