fix(s3): update public URL to include path query parameter

- Updated `getPublicUrl` to use `?path=<key>` format in public URLs.
- Adjusted corresponding test cases to reflect the new URL structure.

backend/src/s3/s3.service.ts

@@ -173,6 +173,6 @@ export class S3Service implements OnModuleInit, IStorageService {
 			baseUrl = `https://api.${domain}`;
 		}
 
-		return `${baseUrl}/media/${storageKey}`;
+		return `${baseUrl}/media?path=${storageKey}`;
 	}
 }