Idempotent start with liveness check and wedged daemon recovery

Add README with usage, routing table, security model, and shell integration

Add debug logging with timing and human-readable message type names

Allow group-writable backend sockets, reject only world-writable

Add loop prevention, write forwarding, and inotify-based agent detection

Timeout split, lock rollback, security hardening, atomic PID, control STOP

Update CLAUDE.md to reflect broadcast lock, per-message state, control UX

Per-message state, broadcast lock, security hardening, control UX

Rename crate, add mux-level lock, smart write routing, control socket

Add sign-failure reload, filesystem scan, extension routing, c_char fix

Add loop prevention, write forwarding, and inotify-based agent detection

Allow unnecessary_cast on ucred fields for cross-libc compat

Fix umask-dependent test_validate_own_socket test

Add fmt check to just check pre-push gate

Add daemon mode, periodic refresh, security hardening to ssh-agent-mux