Third lane of the same contract (found in live staging validation):
/sethome run as a top-level relay-fronted Slack DM message captured the
adapter's session-keying thread stamp (the /sethome message's own id)
into the persisted HomeChannel.thread_id and its legacy env mirror.
Every bare-platform delivery (deliver="slack") then resolved home chat +
home thread and landed inside the ephemeral thread around the old
/sethome message. Extracted _home_thread_from_source with the same
synthetic-stamp recognition as cron origin capture; a /sethome run
inside a genuine thread keeps that thread as the home target. Users
repair an already-poisoned home target by rerunning /sethome.
Victor Kyriazakos