fix: address open triage issues (#21,#26,#45,#46,#47,#30-33)

- #45: re-read local folder when recursive checkbox toggles
- #47: clear Identify crop spinner when image is already cached
- #46: search selected people by person_ids; AND for "First Last"
- #21: enqueue network import without blocking API walk
- #26: serve resized grid thumbnails for photos
- #30/#31/#33: re-enable small-face filters in auto-match

viewer-frontend/lib/photo-utils.ts

@@ -22,9 +22,14 @@ export function isVideo(photo: Photo): boolean {
  * - Videos → use thumbnail endpoint (for grid display)
  */
 export function getImageSrc(photo: Photo, options?: { watermark?: boolean; thumbnail?: boolean }): string {
-  // For videos, use thumbnail endpoint if requested (for grid display)
-  if (options?.thumbnail && isVideo(photo)) {
-    return `/api/photos/${photo.id}/image?thumbnail=true`;
+  // Grid thumbnails: resize on server (images) or video poster (#26)
+  if (options?.thumbnail) {
+    const params = new URLSearchParams();
+    params.set('thumbnail', 'true');
+    if (options.watermark) {
+      params.set('watermark', 'true');
+    }
+    return `/api/photos/${photo.id}/image?${params.toString()}`;
   }
 
   if (isUrl(photo.path)) {