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

backend/app/services/contact_service.py

@@ -137,24 +137,18 @@ async def list_contacts(
     return contacts, total
 
 
-async def get_contact_by_id(
-    db: AsyncSession, contact_id: uuid.UUID
-) -> Contact | None:
+async def get_contact_by_id(db: AsyncSession, contact_id: uuid.UUID) -> Contact | None:
     """Get a single contact by ID, excluding soft-deleted. Eager-loads contact persons."""
     stmt = (
         select(Contact)
         .options(selectinload(Contact.contact_persons))
-        .where(
-            and_(Contact.id == contact_id, Contact.deleted_at.is_(None))
-        )
+        .where(and_(Contact.id == contact_id, Contact.deleted_at.is_(None)))
     )
     result = await db.execute(stmt)
     return result.scalar_one_or_none()
 
 
-async def create_contact(
-    db: AsyncSession, data: dict[str, Any]
-) -> Contact:
+async def create_contact(db: AsyncSession, data: dict[str, Any]) -> Contact:
     """Create a new contact with optional nested contact persons.
 
     The data dict may contain a 'contact_persons' list of dicts.