The changelog for version 2.1.89 is complete. Here's a summary of the key changes I identified:

Major new features:

• Configurable auto-compact window with /autocompact command and thrashing protection
• Terminal tab status showing Idle/Working/Waiting state
• Full mouse text selection and clipboard system with copy-on-select, new scroll keybindings, and tmux integration
• MCP OAuth authentication tool allowing the model to trigger auth flows mid-conversation
• /buddy coding companion — a fun feature that hatches a companion to watch you code
• Recently denied commands view for auto-mode denials
• Session resume with summary option
• defer permission type for hooks with PermissionDenied event

Key improvements:

• Shell security migrated from shell-quote to tree-sitter (more accurate bash analysis)
• Better file edit error messages (stale content, too large, not read yet)
• Improved 1M context messaging and extra usage guidance
• Message rating system
• PowerShell edition detection
• New CLI flags: --include-hook-events, --mcp-config servers, --server-option