Add activity_core/state_hub_write: every State Hub write (report-sink,
ops-evidence, schedule-miss) now sends a stable Idempotency-Key header derived
from run_id:instruction_id:event_type. Makes writes safe to buffer/replay under
the future state-hub beachhead without duplicate progress/triage events. The
read-based _progress_exists dedup is now best-effort (returns False on connection
error instead of hard-failing), so the guarantee lives on the keyed write rather
than a live read. Tests + runbook note. Endpoint adoption / proxy retirement stays
blocked on the state-hub beachhead capability.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Add activity_core/schedule_health: a pure evaluate_schedule_health() verdict
(built on Temporal's num_actions_missed_catchup_window plus a staleness check),
an async check_schedule_health() reader, and post_missed_fire_alert() that emits
a schedule_miss State Hub progress event. Makes a missed fire visible even under
misfire_policy=skip, where Temporal drops it by design. Unit tests for the
verdict logic.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
