TTL inference per base and ttl_downgrade; warmth with init --warm-margin-s; ping rule (activity window, break-even caps 19/11, pings on/off) with C3(d) in-flight dedupe under the lock; pings returned once through wait's pings list, partial refreshes, miss/failed flag ping_missed; tick in every supervisor (60 s), in wait (start + 30 s) and as tick --run (N3-refused). M16: job-file and running-info progress counter renamed to messages. M8: visible-window check widened (console/Terminal diff, positive control, skip without desktop). Billed-error test (stub directive billed).