[Bug]: Screen readers don't hear background threads finish when the sidebar is collapsed, and the announcement doesn't say which thread #23811

Before submitting

• I searched existing issues and did not find a duplicate.
• I included enough detail to reproduce or investigate the problem.

Area

apps/desktop

Steps to reproduce

1. Turn on NVDA and open the T3 Code desktop app.
2. In thread A, send a prompt that takes a while (for example, reading several files and running a command).
3. Switch to thread B while thread A is still working.
4. Collapse the sidebar.
5. Keep focus in thread B's composer and wait for thread A to finish.

Expected behavior

When a thread I'm not in changes status, I hear which thread it was, for example "Done: Fix login redirect" or "Needs approval: Fix login redirect". This works the same whether the sidebar is open or collapsed.

Actual behavior

• Sidebar collapsed: nothing is announced when a background thread finishes, fails or needs me.
• Sidebar open: I hear "Done", but not which thread finished. With several threads running, I can't tell which one it was without going to the sidebar and reading through it.
• The wording also differs from the open thread: background threads say "Pending Approval" and "Awaiting Input", while the open thread says "Needs approval" and "Needs your input".

Impact

Major degradation or frequent failure

Version or commit

T3 Code Nightly 0.1.2-nightly.20261022.3512

Environment

Windows 11 Pro (10.0.26200), NVDA 2026.2

Logs or stack traces

Screenshots, recordings, or supporting files

No response

Workaround

Keep the sidebar open, and when "Done" is heard, move focus to the sidebar and read through the threads to find out which one changed.

Proposed fix (first outline)

This should be picked up once #23752 lands. That PR makes the open thread announce its own status and stops the sidebar from repeating it, which this issue builds on. It came up while testing that PR (comment), and the maintainers agreed it should be its own issue (reply).

1. Announce background thread status from somewhere that keeps working when the sidebar is collapsed.
2. Include the thread's title: ": ".
3. Leave the open thread out, since fix(web): screen readers hear when the open thread starts, needs you or finishes #23752 already covers it.
4. Stay quiet when the app opens or reconnects, so it doesn't read out every thread at once.
5. Announce each status once, instead of from both the sidebar and the new announcement.
6. Use the same wording as the open thread ("Needs approval", "Needs your input").

I have not tested or checked the mobile app.

Related: #23656, #23752