TUI footer says Tab queues even when idle Tab submits

What happened?

The TUI footer shortcut overlay always labels Tab as:

tab to queue message

However, the composer handler submits immediately when no task is running, unless queueing is otherwise forced. There is also an existing test named tab_submits_when_no_task_running, and the tooltip text already describes the nuance:

Press Tab to queue a message when a task is running; otherwise it sends immediately (except `!`).

So the footer label can mislead users when the agent is idle.

Expected behavior

The footer shortcut label should either be conditional or use wording such as “submit/queue message” so it matches the implemented Tab behavior in idle vs running states.

Additional context

I searched open issues and PRs for terms including Tab, queue message, submit, TUI, and footer, and did not find an existing open item that appears to cover this UI copy mismatch.