fix part 3

backend/app/database/models/image.py

@@ -1,10 +1,10 @@
 """Image database model."""
 
-from datetime import datetime, timezone
+from datetime import datetime
 from typing import TYPE_CHECKING
 from uuid import UUID, uuid4
 
-from sqlalchemy import BigInteger, DateTime, ForeignKey, Integer, String
+from sqlalchemy import BigInteger, DateTime, ForeignKey, Integer, String, func
 from sqlalchemy.dialects.postgresql import JSONB
 from sqlalchemy.dialects.postgresql import UUID as PGUUID
 from sqlalchemy.orm import Mapped, mapped_column, relationship
@@ -38,7 +38,7 @@ class Image(Base):
     height: Mapped[int] = mapped_column(Integer, nullable=False)
     image_metadata: Mapped[dict] = mapped_column(JSONB, nullable=False)
 
-    created_at: Mapped[datetime] = mapped_column(DateTime, nullable=False, default=lambda: datetime.now(timezone.utc))
+    created_at: Mapped[datetime] = mapped_column(DateTime, nullable=False, server_default=func.now())
     reference_count: Mapped[int] = mapped_column(Integer, nullable=False, default=0)
 
     # Relationships