feat: Implement automatic updated_at timestamp management in BaseModel and update BaseRepository to reflect changes

app/models/base.py

@@ -1,5 +1,6 @@
 from datetime import UTC, datetime
 
+from sqlalchemy import event
 from sqlmodel import Field, SQLModel
 
 
@@ -11,3 +12,10 @@ class BaseModel(SQLModel):
     # timestamps
     created_at: datetime = Field(default_factory=lambda: datetime.now(UTC))
     updated_at: datetime = Field(default_factory=lambda: datetime.now(UTC))
+
+
+# SQLAlchemy event listener to automatically update updated_at timestamp
+@event.listens_for(BaseModel, "before_update", propagate=True)
+def update_timestamp(mapper, connection, target):
+    """Automatically set updated_at timestamp before update operations."""
+    target.updated_at = datetime.now(UTC)

app/repositories/base.py

@@ -114,6 +114,7 @@ class BaseRepository[ModelType]:
             for field, value in update_data.items():
                 setattr(entity, field, value)
 
+            # The updated_at timestamp will be automatically set by the SQLAlchemy event listener
             self.session.add(entity)
             await self.session.commit()
             await self.session.refresh(entity)