Harden app for 24-7 offline-first operation

lib/main.dart

@@ -1,3 +1,7 @@
+import 'dart:async';
+import 'dart:io';
+import 'dart:ui';
+
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_riverpod/flutter_riverpod.dart';
@@ -11,7 +15,44 @@ import 'features/home/home_view.dart';
 
 void main() async {
   WidgetsFlutterBinding.ensureInitialized();
+  FlutterError.onError = (details) {
+    FlutterError.presentError(details);
+    debugPrint('[Fatal][FlutterError] ${details.exceptionAsString()}');
+  };
+  PlatformDispatcher.instance.onError = (error, stack) {
+    debugPrint('[Fatal][PlatformDispatcher] $error');
+    debugPrintStack(stackTrace: stack);
+    return true;
+  };
+  ErrorWidget.builder = (details) {
+    return const Material(
+      color: SacredColors.background,
+      child: Center(
+        child: Padding(
+          padding: EdgeInsets.all(32),
+          child: Text(
+            'Terjadi gangguan tampilan.\nAplikasi tetap berjalan dalam mode aman.',
+            textAlign: TextAlign.center,
+            style: TextStyle(
+              color: SacredColors.onSurface,
+              fontSize: 24,
+              fontWeight: FontWeight.w700,
+            ),
+          ),
+        ),
+      ),
+    );
+  };
 
+  await runZonedGuarded(() async {
+    await _bootstrapAndRun();
+  }, (error, stack) {
+    debugPrint('[Fatal][Zone] $error');
+    debugPrintStack(stackTrace: stack);
+  });
+}
+
+Future<void> _bootstrapAndRun() async {
   // Landscape-only for TV
   await SystemChrome.setPreferredOrientations([
     DeviceOrientation.landscapeLeft,
@@ -33,6 +74,7 @@ void main() async {
   if (settingsBox.get('default') == null) {
     await settingsBox.put('default', AppSettings());
   }
+  await _sanitizeMediaSettings(settingsBox);
 
   // Initialize date formatting for Indonesian locale
   await initializeDateFormatting('id_ID');
@@ -47,6 +89,33 @@ void main() async {
   );
 }
 
+Future<void> _sanitizeMediaSettings(Box<AppSettings> settingsBox) async {
+  final settings = settingsBox.get('default');
+  if (settings == null) return;
+
+  final validSlides = settings.slideshowImages
+      .where((path) => path.trim().isNotEmpty && File(path).existsSync())
+      .toList();
+  final brandedBg = (settings.brandedBgImage != null &&
+          settings.brandedBgImage!.trim().isNotEmpty &&
+          File(settings.brandedBgImage!).existsSync())
+      ? settings.brandedBgImage
+      : null;
+
+  final needsSave =
+      validSlides.length != settings.slideshowImages.length ||
+      brandedBg != settings.brandedBgImage;
+  if (!needsSave) return;
+
+  await settingsBox.put(
+    'default',
+    settings.copyWith(
+      slideshowImages: validSlides,
+      brandedBgImage: brandedBg,
+    ),
+  );
+}
+
 class JamShalatApp extends ConsumerWidget {
   const JamShalatApp({super.key});