Cmd+Shift+[ and Cmd+Shift+] now cycle through visible sessions only (parents + expanded children) and no longer include Instance Info. Sidebar session list auto-scrolls to keep the active session row in view.
Show sessions as parent/child threads with expand/collapse and improved agent row styling. Keep a 5-session cache to avoid refetching messages when switching between recently visited sessions.
- Add clipboard utility with fallback for non-secure contexts
- Implement modern Clipboard API with document.execCommand fallback
- Update copy buttons in code blocks, markdown, messages, and session list
- Add proper error handling and user feedback for copy operations
Fixes issue where copy buttons did not work in web browsers served over HTTP or without Clipboard API support
