feat: use custom type to handle existing naive datetimes

app/models/types.py

@@ -0,0 +1,21 @@
+from datetime import timezone
+
+from sqlalchemy import DateTime, TypeDecorator
+
+
+class AwareDateTime(TypeDecorator):
+    impl = DateTime(timezone=True)
+
+    cache_ok = True
+
+    def process_bind_param(self, value, dialect):
+        # Ensure the value is aware. If it's naive, assume UTC.
+        if value is not None and value.tzinfo is None:
+            value = value.replace(tzinfo=timezone.utc)
+        return value
+
+    def process_result_value(self, value, dialect):
+        # Ensure the value is aware. If it's naive, assume UTC.
+        if value is not None and value.tzinfo is None:
+            value = value.replace(tzinfo=timezone.utc)
+        return value