fix: review follow-ups without requiring contributor reopen rights

[Jammy2211]

Summary

External contributors can post new requests on answered or closed threads without being able to reopen them. Community now retains Ears' post-settlement review candidates, keeps closed issues out of open counts, and makes incomplete direct triage unknown instead of suppressing it because an answer was accepted.

The review guidance distinguishes actionable requests, acknowledgements and uncertainty. Closed-thread triage reads the acting account's viewerCanReopen; it never infers the contributor's permissions or requires reopening for a request to receive attention. No GitHub state changes or replies are performed.

Scripts Changed

• agents/conductors/community/_ears_feed.py: validate the optional follow-up observation; preserve stale/cached observations without claiming current response state.
• agents/conductors/community/_community.py: expose review guidance and read-only reopening capability; show candidates in scan output.
• Community instructions and tests cover the amended contract.

Validation

66 targeted community/adapter tests passed. The Ears producer's regression suite and generated-state validation exercise the new extension. Legacy snapshots remain accepted.

Integration

Companion Ears producer: PyAutoLabs/PyAutoEars#20 (task PyAutoLabs/PyAutoEars#19). Merge this reader support before the Ears change. Tier: judge; human merge.

Heart

The user explicitly acknowledged these exact Heart YELLOW reasons on 2026-10-07 and authorized pushing branches and opening PRs (no merge/release):

• manifest drift: shared-standards blocks (generated) — 2 mismatch(es) vs PyAutoMind/repos.yaml
• release validation stale: source moved since rehearsal (PyAutoNerves, PyAutoFit, PyAutoArray, PyAutoGalaxy, PyAutoLens)