Clears stale .git/index.lock files before git write commands.
Claude Code's internal git status polling leaves orphan locks
(anthropics/claude-code#11005) that block add/commit/merge/push.
The hook checks lsof/fuser before removing — only stale locks are
cleared, never locks held by live processes. Read-only git commands
are skipped entirely.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
