Show OSC 7501 program status in terminal tabs

[maxffarrell]

When several agents run in T3 Code's embedded terminals, I'd like to see which tab is working, waiting for me, finished, or failed without opening each one.

Please consume the Program Status Protocol (OSC 7501) and show its state in terminal tabs: working, blocked (permission/question/auth), done, error, and idle. Honor clear and per-program record lifetimes so stale state disappears. Terminal process status alone doesn't identify an agent waiting for approval.

Crush already emits this protocol, and cmux supports receiving it. This would also work for other CLI agents as they adopt it. I searched existing issues and Ideas discussions and didn't find this request.