fix: complete image pipeline - rotation, URL, preview

- Add rotation_degrees parameter to ImageProcessor.process_photo()
- Pass rotation through _auto_save_photo_from_extraction() to processor
- Allow no-crop fallback when crop_bounds is None
- Add buildPhotoUrl() helper to resolve backend URLs correctly
- Update frontend components to use backend URL for image sources
- Replace Use/Skip Photo buttons with checkbox in AI extraction UI
- Add images/ to .gitignore to prevent accidental commits

Addresses: rotation never applied, image 404s (relative to Next.js not backend), preview blank in edit form

frontend/lib/api.ts

@@ -47,6 +47,11 @@ export const getBackendUrl = async () => {
   return `http://${host}:${config.BACKEND_PORT}`;
 };
 
+export const buildPhotoUrl = (backendUrl: string, photoPath: string): string => {
+  if (!photoPath) return '';
+  return `${backendUrl}${photoPath}`;
+};
+
 /**
  * [C-01] Axios instance cu JWT Bearer token în header
  * și interceptor pentru 401 Unauthorized (token expired)