Adds an interactive sidebar to the Commit Graph webview providing quick access to branches, remotes, stashes, tags, and worktrees.

• Supports both list and tree layouts for better navigation of repository references
• Includes real-time status indicators (e.g., tracking info, active worktrees, uncommitted changes) and rich tooltips
• Adds context menu support and inline actions for common Git operations directly from the sidebar
• Implements a split-panel interface allowing users to resize or toggle the sidebar
• Supports alternate actions via Alt key for tree items
• Persists filter state in memory across panel reloads