fix(scripts): use datetime.now() instead of utcnow() to match server timezone

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

scripts/send_portal_message.py

@@ -51,8 +51,8 @@ def find_or_create_conversation(db, from_user_id, to_user_id):
     conv = Conversation(
         is_group=False,
         owner_id=from_user_id,
-        created_at=datetime.utcnow(),
-        updated_at=datetime.utcnow(),
+        created_at=datetime.now(),
+        updated_at=datetime.now(),
     )
     db.add(conv)
     db.flush()
@@ -61,13 +61,13 @@ def find_or_create_conversation(db, from_user_id, to_user_id):
         conversation_id=conv.id,
         user_id=from_user_id,
         role='owner',
-        joined_at=datetime.utcnow(),
+        joined_at=datetime.now(),
     ))
     db.add(ConversationMember(
         conversation_id=conv.id,
         user_id=to_user_id,
         role='member',
-        joined_at=datetime.utcnow(),
+        joined_at=datetime.now(),
     ))
     db.flush()
 
@@ -81,7 +81,7 @@ def send_message(db, conv, sender_id, content):
         conversation_id=conv.id,
         sender_id=sender_id,
         content=content,
-        created_at=datetime.utcnow(),
+        created_at=datetime.now(),
     )
     db.add(msg)
     db.flush()