🐛 Fix dictionary iteration bug in file processing

- Fixed 'dictionary changed size during iteration' error
- Create copy of photo items before iterating and modifying dictionary
- File uploads and signed URL generation now work without errors

The bug was occurring when adding *_url keys to photos dictionary while iterating over it.

supabase_storage.py

@@ -131,7 +131,9 @@ class SupabaseFileStorage:
             if processed_data.get('photographs'):
                 photos = processed_data['photographs']
                 if isinstance(photos, dict):
-                    for category, file_path in photos.items():
+                    # Create a copy of items to avoid dictionary size change during iteration
+                    photo_items = list(photos.items())
+                    for category, file_path in photo_items:
                         if file_path:
                             try:
                                 photos[f"{category}_url"] = self.get_image_url(file_path)