* Persist agents sidebar search field visibility as pairing-local preferen
- Add `agentsShowSearch` to workspace UI state with default on
- Include in pairing-local fields so preference syncs across clients
- Convert search from menu action to checkbox menu item for explicit toggle
- Update activity thread options menu to reflect checkbox state
- Add localization strings across all supported languages
- Update RPC schemas and preference persistence layer
- Includes readiness validation reports confirming feature is clean
* rm review
* fix documentation