non UNIQUE username

[Theacebutler]

the user model has a unique=True but the route only checks for existing email, not username

class User(Base):
 __tablename__ = "users"
id = Column(Uuid(as_uuid=True), primary_key=True, index=True, default=uuid.uuid4)
user_name = Column(String, unique=True, index=True)
email = Column(String, unique=True, index=True)

And:

@router.post("/signup")
async def signup(user: CreateUser, db=Depends(get_db)):
    existing_user = db.query(User).filter(User.email == user.email).first()
    if existing_user:
        raise HTTPException(status_code=400, detail="Email already registered")