libtmux:lock-server

Request locking of all attached frontends on CLIENT's daemon. Return a COMMAND-OUTCOME after guarded dispatch. Live frontend membership determines the recipients; this is wider than one captured session. Each frontend runs its configured lock-command. Control clients, suspended frontends and empty/oversized commands are skipped. Success acknowledges the request, not startup, completion or authentication. Blocks under shared preflight/dispatch limits and returns no replacement. Failures retain their outcome. Lock programs belong to the frontends; closing CLIENT leaves them running. Never retries.