Summary:

- Added a rename action for agent threads in the sidebar.
- Persisted renamed thread titles and kept open thread views in sync.

Release Notes:

- Improved agent threads by allowing them to be renamed directly from
the sidebar.

---------

Co-authored-by: Danilo Leal <daniloleal09@gmail.com>
Co-authored-by: Bennet Bo Fenner <bennetbo@gmx.de>