libtmux:lock-session

Request locking of SESSION's attached frontends; return a COMMAND-OUTCOME. CLIENT must own the captured SESSION. The live session membership determines which frontends receive the request. Each 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. Foreign or vanished sessions signal STALE-TARGET; other failures retain their outcome. Lock programs belong to the frontends; closing CLIENT leaves them running. Never retries.