feat: wire up app shell, log mood screen, and fix Android build

- Bootstrap ProviderScope in main.dart and move App to app.dart with light/dark theming
- Add initial LogMoodScreen with mood entry flow and shared activity/mood widgets
- Add kIsWeb guard in app_database.dart for drift web support
- Enable Android core library desugaring required by flutter_local_notifications 21.x
- Guard all async notifier state assignments with ref.mounted checks to prevent
  use-after-dispose errors when providers are auto-disposed mid-operation

lib/core/providers/activity_provider.dart

@@ -50,7 +50,7 @@ class ActivityNotifier extends Notifier<AsyncValue<void>> {
     required String colourHex,
   }) async {
     state = const AsyncLoading();
-    state = await AsyncValue.guard(
+    final next = await AsyncValue.guard(
       () => ref.read(activityDaoProvider).insertActivity(
             ActivitiesCompanion.insert(
               name: name,
@@ -60,13 +60,17 @@ class ActivityNotifier extends Notifier<AsyncValue<void>> {
             ),
           ),
     );
+    if (!ref.mounted) return;
+    state = next;
   }
 
   Future<void> deleteActivity(int id) async {
     state = const AsyncLoading();
-    state = await AsyncValue.guard(
+    final next = await AsyncValue.guard(
       () => ref.read(activityDaoProvider).deleteActivity(id),
     );
+    if (!ref.mounted) return;
+    state = next;
   }
 }
 

lib/core/providers/insight_provider.dart

@@ -37,6 +37,7 @@ class InsightNotifier extends Notifier<AsyncValue<String?>> {
     final dao = ref.read(insightDaoProvider);
 
     final cached = await dao.getCached(hash);
+    if (!ref.mounted) return;
     if (cached != null) {
       state = AsyncData(cached.responseText);
       return;
@@ -62,6 +63,7 @@ class InsightNotifier extends Notifier<AsyncValue<String?>> {
             rangeEnd: Value(rangeEnd),
           ),
         );
+    if (!ref.mounted) return;
     state = AsyncData(responseText);
   }
 

lib/core/providers/llm_provider.dart

@@ -33,11 +33,12 @@ class LlmResponseNotifier extends Notifier<AsyncValue<String>> {
 
     try {
       await for (final token in service.generateStream(prompt)) {
-        if (_cancelled) break;
+        if (_cancelled || !ref.mounted) break;
         buffer.write(token);
         state = AsyncData(buffer.toString());
       }
     } catch (e, st) {
+      if (!ref.mounted) return;
       state = AsyncError(e, st);
     }
   }

lib/core/providers/mood_provider.dart

@@ -57,7 +57,7 @@ class MoodEntryNotifier extends Notifier<AsyncValue<void>> {
     DateTime? timestamp,
   }) async {
     state = const AsyncLoading();
-    state = await AsyncValue.guard(() async {
+    final next = await AsyncValue.guard(() async {
       final dao = ref.read(moodDaoProvider);
       await dao.insertEntryWithActivities(
         entry: MoodEntriesCompanion.insert(
@@ -69,13 +69,17 @@ class MoodEntryNotifier extends Notifier<AsyncValue<void>> {
         tagIds: tagIds,
       );
     });
+    if (!ref.mounted) return;
+    state = next;
   }
 
   Future<void> deleteEntry(int id) async {
     state = const AsyncLoading();
-    state = await AsyncValue.guard(
+    final next = await AsyncValue.guard(
       () => ref.read(moodDaoProvider).deleteEntry(id),
     );
+    if (!ref.mounted) return;
+    state = next;
   }
 
   Future<void> updateEntry({
@@ -85,7 +89,7 @@ class MoodEntryNotifier extends Notifier<AsyncValue<void>> {
     DateTime? timestamp,
   }) async {
     state = const AsyncLoading();
-    state = await AsyncValue.guard(
+    final next = await AsyncValue.guard(
       () => ref.read(moodDaoProvider).updateEntry(
             MoodEntriesCompanion(
               id: Value(id),
@@ -95,6 +99,8 @@ class MoodEntryNotifier extends Notifier<AsyncValue<void>> {
             ),
           ),
     );
+    if (!ref.mounted) return;
+    state = next;
   }
 }
 

lib/core/providers/settings_provider.dart

@@ -27,6 +27,7 @@ class SettingsNotifier extends Notifier<AsyncValue<void>> {
 
   Future<void> set(String key, String value) async {
     await ref.read(settingsDaoProvider).set(key, value);
+    if (!ref.mounted) return;
     ref.invalidate(settingProvider(key));
   }