Distinguish between invalid question state and tab re-open in current session

[hungngodev]

Description:
Currently, the UI does not differentiate between two distinct states:

1. User reopens a tab while already in the correct session/question (e.g. refreshing or accidental tab close)
2. User navigates to an incorrect session/question (e.g. due to desync, URL manipulation, or timing issues)

Both situations currently look the same in the UI, which can be confusing and lead to improper actions (like triggering "Join Room" or recreating sessions unnecessarily).

Expected Behavior:

• When the user reopens a tab and is in the correct session, restore the editor and resume without showing fallback UI.
• When the user is in an invalid or mismatched session/question, prompt an appropriate error or redirect them to the correct question/session if possible.