libtmux:lock-client

Request locking of captured terminal TARGET; return a COMMAND-OUTCOME. The frontend runs the session's configured lock-command through its shell. Success acknowledges the request, not lock startup, completion or authentication. An already suspended frontend or an empty/oversized lock command can be a no-op. CLIENT must own TARGET. Blocks under shared preflight/dispatch limits; returns no replacement. Stale or foreign targets signal STALE-TARGET; other failures retain their outcome. Preflight cannot exclude client replacement before dispatch. Never retries.