Fix role toggle functionality where switching message roles (assistant/system)
did not update the UI immediately and required page refresh to see changes.
Changes:
- Add message.role comparison in OptimizedMessageContent memo function
- Add message.role comparison in OptimizedMessageActions memo function
The issue was caused by React.memo optimization that wasn't tracking role
changes, preventing re-renders when only the message role property changed.
Now role switches are reflected immediately in both message content display
and action button states.
Fixes: Role switching requires page refresh to display correctly
