feat: Update category deletion logic to reset related notes and track changes

lib/data/app_database.dart

@@ -86,7 +86,11 @@ class AppDatabase extends _$AppDatabase {
 
   Future<void> deleteCategory(String id) {
     return (update(categories)..where((c) => c.id.equals(id))).write(
-      CategoriesCompanion(isDeleted: Value(true)),
+      CategoriesCompanion(
+        isDeleted: const Value(true),
+        updatedAt: Value(DateTime.now()),
+        isDirty: const Value(true),
+      ),
     );
   }
 

lib/data/note_repository.dart

@@ -87,6 +87,11 @@ class NoteRepository {
 
   Future<void> deleteCategory(String id) async {
     await _database.deleteCategory(id);
+
+    await _database.customStatement(
+      'UPDATE notes SET category_id = NULL, is_dirty = 1 WHERE category_id = ?',
+      [id],
+    );
   }
 
   Future<Note> createNote(Note note) async {

lib/data/sync_models.dart

@@ -258,6 +258,7 @@ class SyncCategoryResponse {
       colorValue: colorValue,
       iconCodePoint: iconCodePoint,
       updatedAt: updatedAt,
+      isDirty: false,
     );
   }
 }