debug option to delete vectorDB index

mobile/apps/photos/lib/db/ml/clip_vector_db.dart

@@ -279,17 +279,23 @@ class ClipVectorDB {
     }
   }
 
-  Future<void> deleteIndexFile() async {
+  Future<void> deleteIndexFile({bool undoMigration = false}) async {
     try {
       final documentsDirectory = await getApplicationDocumentsDirectory();
-      final String dbPath =
-          join(documentsDirectory.path, _databaseName);
+      final String dbPath = join(documentsDirectory.path, _databaseName);
       _logger.info("Delete index file: DB path " + dbPath);
       final file = File(dbPath);
       if (await file.exists()) {
         await file.delete();
       }
       _logger.info("Deleted index file on disk");
+      _vectorDbFuture = null;
+      if (undoMigration) {
+        final prefs = await SharedPreferences.getInstance();
+        await prefs.setBool(_kMigrationKey, false);
+        _migrationDone = false;
+        _logger.info("Undid migration flag");
+      }
     } catch (e, s) {
       _logger.severe("Error deleting index file on disk", e, s);
       rethrow;

mobile/apps/photos/lib/ui/settings/debug/ml_debug_section_widget.dart

@@ -83,6 +83,24 @@ class _MLDebugSectionWidgetState extends State<MLDebugSectionWidget> {
     logger.info("Building ML Debug section options");
     return Column(
       children: [
+        sectionOptionSpacing,
+        MenuItemWidget(
+          captionedTextWidget: const CaptionedTextWidget(
+            title: "Clear vectorDB index",
+          ),
+          pressedColor: getEnteColorScheme(context).fillFaint,
+          trailingIcon: Icons.chevron_right_outlined,
+          trailingIconIsMuted: true,
+          onTap: () async {
+            try {
+              await ClipVectorDB.instance.deleteIndexFile(undoMigration: true);
+              showShortToast(context, 'Deleted vectorDB index');
+            } catch (e, s) {
+              logger.severe('vectorDB index delete failed ', e, s);
+              await showGenericErrorDialog(context: context, error: e);
+            }
+          },
+        ),
         sectionOptionSpacing,
         MenuItemWidget(
           captionedTextWidget: const CaptionedTextWidget(