fix: ruff lint + format fixes in tests, ESLint fixes in frontend

backend/app/services/mobilede_service.py

@@ -48,9 +48,7 @@ def _get_status_url(listing_id: str) -> str:
     return f"{_MOBILE_DE_API_BASE}/api/seller/listings/{listing_id}/status"
 
 
-async def push_listing(
-    db: AsyncSession, vehicle: Vehicle
-) -> MobileDeListing:
+async def push_listing(db: AsyncSession, vehicle: Vehicle) -> MobileDeListing:
     """Push a vehicle listing to mobile.de.
 
     Creates a MobileDeListing record with status 'pending',
@@ -150,9 +148,7 @@ async def update_listing(
     return listing
 
 
-async def delete_listing(
-    db: AsyncSession, listing: MobileDeListing
-) -> MobileDeListing:
+async def delete_listing(db: AsyncSession, listing: MobileDeListing) -> MobileDeListing:
     """Delete a listing from mobile.de.
 
     Sends DELETE /api/seller/listings/{id}.
@@ -228,8 +224,7 @@ async def retry_failed_listing(
     if retry_count >= MAX_RETRIES:
         listing.sync_status = "fehler"
         listing.error_log = (
-            f"Max retries ({MAX_RETRIES}) exceeded. "
-            f"Last error: {listing.error_log}"
+            f"Max retries ({MAX_RETRIES}) exceeded. Last error: {listing.error_log}"
         )
         await db.flush()
         await db.refresh(listing)