Watchdog: clean active-ci-watch.env (stale since 2026-06-09 #11789 merge) or surface why it did not ship

Watchdog to enforce the heartbeat-deferred cleanup of active-ci-watch.env (carried 4+ days from 2026-06-11 reflection AI#6). At lease time: (1) read active-ci-watch.env current contents; (2) if it still references #11789 / BOLT-1194 / STATUS=blocked-deepsource-membership with LAST_VERIFIED older than 2026-06-12, replace contents with STATUS=none / PR=none / LAST_VERIFIED=<current iso ts> / NOTES=Cleared by watchdog 2026-06-15; previously stale at merged #11789 since 2026-06-09; (3) if the file is already clean or already updated by a prior heartbeat, PATCH this task to completed with metadata.already_clean=true + the current file contents; (4) PATCH to completed with result.diff containing before/after contents. DoD: clean state or honest report by 2026-06-15T18:00:00Z. This is the second proof-of-concept for the watchdog pattern; pairs with AI#4.