docs: D-1 remainder — stale Internal-ops framing and OQ list

Completes review 001 D-1 (vision.md's half landed with ADR-015):

- alk-stack.md gitea-lesson item 2: supersession note pointing at
  ADR-012 §3 / ADR-015 (repo ops are External, scope + manage grant —
  right mechanism, wrong axis).
- AGENTS.md lifecycle status: active OQ list updated (OQ-03
  partially resolved, OQ-05 deferred, OQ-16 deferred; OQ-04/06/08
  resolved via ADR-013/012/011).
- review 001: D-1 marked resolved.

All three stale statements were pre-decomposition landmines: research
docs are declared 'current source of truth' by AGENTS.md, so the
superseded admin-API design needed marking.

AGENTS.md

@@ -187,8 +187,12 @@ docs, branch dropped) or standalone mode (POC independent of repo code;
 scratch project at `/workspace/<poc-name>`). POCs have relaxed
 constraints (comments/unwrap acceptable) — they are exploration tools,
 not production code. Open architecture questions live in
-`docs/architecture/open-questions.md` (OQ-04 receive-pack, OQ-06
-registry backing, OQ-08 identity model are the active ones).
+`docs/architecture/open-questions.md` (the active set: OQ-03 —
+partially resolved, the publish freeze inventory — and OQ-05 —
+sha256 policy, deferred on ecosystem need; OQ-16 — grant-key identity
+namespace, deferred on the distributed phase. OQ-04 receive-pack, OQ-06
+registry backing, and OQ-08 identity model are resolved: ADR-013,
+ADR-012, ADR-011).
 
 ## Architecture Context