v0.5.1

Added

• Bundled librarian skill -- structured research workflow for open-source libraries with GitHub permalinks, combining fetch_content (cloning), web_search (recent info), and git operations (blame, log, show)

Fixed

• Session fork event handler was registered as session_branch (non-existent event) instead of session_fork, meaning forks never triggered cleanup (abort pending fetches, clear clone cache, restore session data)
• API fallback title for tree URLs with a path (e.g. /tree/main/src) now includes the path (owner/repo - src), consistent with clone-based results
• Removed unnecessary export on getDefaultBranch (only used internally by fetchViaApi)