DL-192

The root-manager Setup-thread first-turn flow: a postSetupThread step in serve_seed.go fired from seedRootSupervisor on BOTH up-arms after the supervisor seed, posting the embedded versioned setup_thread.md content as @compass into the supervisor’s home channel, made idempotent by a supervisor-scoped client_request_id (content-invariant — the same supervisor id yields the same key, so a content revision never re-posts)

Status: Active (Matt, 2026-08-14)

Record: ../../agent/compass-system-sender-first-turn/design.md#b–the-setup-thread-first-turn-flow