refactor: clean up 55 lint warnings and issues

- Remove all 31 avoid_print debug statements across codebase
- Fix 8 critical warnings (unused variables, unreachable defaults, etc)
- Update deprecated APIs: launch() → launchUrl(), textScaleFactor → textScaler
- Replace deprecated surfaceVariant → surfaceContainerHighest in Material 3 themes
- Refactor switch statements to use modern pattern matching
- Remove unused code: _showDialog, _initNoLocation, _getAnchorOffset
- Fix use_build_context_synchronously by adding mounted checks
- Add ignore_for_file annotations to generated JSON serialization files
- Fix type annotations in appState.dart and models

Warnings reduced from 301 to 246 issues (8 → 0 critical warnings).
Build verified: app-production-debug.apk (160MB) compiles successfully.
Zero type errors, Dart analysis clean for critical issues.

lib/fireNotificationList.dart

@@ -150,8 +150,6 @@ class _FireNotificationListState extends State<FireNotificationList> {
     return StoreConnector<AppState, _ViewModel>(
         distinct: true,
         converter: (Store<AppState> store) {
-          print(
-              'New ViewModel of Fires Notifications (unread: ${store.state.fireNotificationsUnread})');
           return _ViewModel(
               isLoaded: store.state.isLoaded,
               onDeleteAll: () {
@@ -183,7 +181,6 @@ class _FireNotificationListState extends State<FireNotificationList> {
         builder: (BuildContext context, _ViewModel view) {
           final bool hasFireNotifications = view.fireNotifications.isNotEmpty;
           final String title = S.of(context).fireNotificationsTitle;
-          print('Building Fire Notifications List');
 
           return Scaffold(
               key: _scaffoldKey,
@@ -221,7 +218,8 @@ class _FireNotificationListState extends State<FireNotificationList> {
                                             .of(context)
                                             .fireNotificationsDescription,
                                         textAlign: TextAlign.center,
-                                        textScaleFactor: 1.1,
+                                        textScaler:
+                                            const TextScaler.linear(1.1),
                                         style: const TextStyle(
                                             height: 1.3, color: Colors.black45))
                                   ]))))
@@ -240,7 +238,7 @@ class _FireNotificationListState extends State<FireNotificationList> {
     Navigator.push(
         context,
         MaterialPageRoute<void>(
-            builder: (BuildContext context) => genericMap()));
+            builder: (BuildContext context) => const genericMap()));
   }
 
   Future<void> _showConfirmDialog(_ViewModel view) {