feat(settings): add orphaned thumbnail cleanup to General section

Scans the thumbnails directory and cross-references against thumbnail_path
values in the images table, deleting any files not linked to an indexed image.
Surfaces count and reclaimable MB in the General section alongside the
existing Compact database card.

src/store.ts

@@ -82,6 +82,16 @@ export interface VacuumResult {
   freed_mb: number;
 }
 
+export interface OrphanedThumbnailsInfo {
+  count: number;
+  size_mb: number;
+}
+
+export interface CleanupOrphanedThumbnailsResult {
+  deleted_count: number;
+  freed_mb: number;
+}
+
 export interface TaggerModelStatus {
   model_id: string;
   model_name: string;
@@ -353,6 +363,8 @@ interface GalleryState {
   openAppDataFolder: () => Promise<void>;
   getDatabaseInfo: () => Promise<DatabaseInfo>;
   vacuumDatabase: () => Promise<VacuumResult>;
+  getOrphanedThumbnailsInfo: () => Promise<OrphanedThumbnailsInfo>;
+  cleanupOrphanedThumbnails: () => Promise<CleanupOrphanedThumbnailsResult>;
   retryFailedEmbeddings: (folderId: number) => Promise<void>;
   updateImageDetails: (imageId: number, updates: { favorite?: boolean; rating?: number }) => Promise<void>;
   setCacheDir: (dir: string) => void;
@@ -1367,6 +1379,10 @@ export const useGalleryStore = create<GalleryState>((set, get) => ({
 
   vacuumDatabase: () => invoke<VacuumResult>("vacuum_database"),
 
+  getOrphanedThumbnailsInfo: () => invoke<OrphanedThumbnailsInfo>("get_orphaned_thumbnails_info"),
+
+  cleanupOrphanedThumbnails: () => invoke<CleanupOrphanedThumbnailsResult>("cleanup_orphaned_thumbnails"),
+
   loadTaggerModelStatus: async () => {
     try {
       const taggerModelStatus = await invoke<TaggerModelStatus>("get_tagger_model_status");