## Summary

- Follow up on #63578 by extending the existing
`agent::RenameSelectedThread` action to the active Terminal Thread in
the Agent Panel.
- Preserve the existing Threads Sidebar behavior and default
keybindings.
- Document custom keymap assignment and add focused Agent Panel
regression coverage.

## Testing

- `cargo test -p agent_ui
agent_panel::tests::test_rename_selected_thread_action --lib`
- `cargo test -p sidebar rename_selected_thread --lib`
- `cargo fmt --package agent_ui -- --check`
- `npx prettier --check src/ai/terminal-threads.md`
- Manually tested locally with a custom `AgentPanel > Terminal` keymap
binding.

Release Notes:

- Added support for custom keybindings to rename Terminal Thread titles
from the Agent Panel.

### screenshots
<img width="921" height="205" alt="Screenshot 2026-09-02 at 18 40 31"
src="https://github.com/user-attachments/assets/b1edabfc-35f9-42ef-b368-486003202349"
/>