Sidebar flashes deleted session IDs

[giulianob]

Describe the bug

The 'sidebar-sessions-state' json file does not seem to remove old session. The sidebar will periodically flash the session IDs of outdated sessions.

Affected version

GitHub Copilot CLI 1.0.81

Steps to reproduce the behavior

1. Prune old sessions
2. Open sidebar
3. Notice sidebar periodically flashes, especially when there's mouse input

Expected behavior

Old sessions are removed from session file properly

Additional context

No response