Fix critical issues: gallery authentication and photo duplication

- Fix gallery-specific authentication for images
  - Update AuthenticatedImage component to use gallery-specific tokens
  - Add isGallery prop to distinguish between admin and gallery contexts
  - Update PhotoGrid and PhotoLightbox to pass isGallery prop

- Fix photo duplication issue in fileWatcher service
  - Add check to prevent duplicate photo entries when backend restarts
  - File watcher now verifies if photo exists before inserting
  - Cleaned up 176 duplicate photos from database

These fixes resolve:
1. Gallery images not loading due to auth token errors
2. Photo count increasing without new uploads due to duplicates

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

frontend/src/components/common/AuthenticatedImage.tsx

@@ -5,6 +5,7 @@ interface AuthenticatedImageProps extends React.ImgHTMLAttributes<HTMLImageEleme
   src: string;
   fallbackSrc?: string;
   useWatermark?: boolean;
+  isGallery?: boolean;
 }
 
 export const AuthenticatedImage: React.FC<AuthenticatedImageProps> = ({
@@ -12,6 +13,7 @@ export const AuthenticatedImage: React.FC<AuthenticatedImageProps> = ({
   fallbackSrc,
   alt,
   useWatermark = false,
+  isGallery = false,
   ...props
 }) => {
   const [imageSrc, setImageSrc] = useState<string>('');
@@ -21,7 +23,20 @@ export const AuthenticatedImage: React.FC<AuthenticatedImageProps> = ({
   useEffect(() => {
     let objectUrl: string | null = null;
 
-    const token = getAuthToken();
+    // Determine which token to use based on context
+    let token: string | undefined;
+    
+    if (isGallery) {
+      // For gallery images, get the gallery-specific token
+      const pathParts = window.location.pathname.split('/');
+      if (pathParts[1] === 'gallery' && pathParts[2]) {
+        const gallerySlug = pathParts[2];
+        token = localStorage.getItem(`gallery_token_${gallerySlug}`) || undefined;
+      }
+    } else {
+      // For admin images, use the admin token
+      token = getAuthToken(true);
+    }
     
     if (!src) {
       setImageSrc(fallbackSrc || '');
@@ -89,7 +104,7 @@ export const AuthenticatedImage: React.FC<AuthenticatedImageProps> = ({
         URL.revokeObjectURL(objectUrl);
       }
     };
-  }, [src, fallbackSrc, useWatermark]);
+  }, [src, fallbackSrc, useWatermark, isGallery]);
 
   if (isLoading) {
     return (