ADR-021: third review round — tx-read methods, Job.claimed_at, schedule() queue validation, drop=rollback, receiver arms

docs/architecture/README.md

@@ -1,6 +1,6 @@
 ---
 status: draft
-last_updated: 2026-10-06 (ADR-019/020 — second review round resolved)
+last_updated: 2026-10-07 (ADR-021 — third review round resolved)
 ---
 
 # alkstore — Architecture
@@ -55,6 +55,7 @@ pending architecture review and OQ resolution.
 | [018](decisions/018-provenance-register-and-cherry-picks.md) | Substrate provenance register and cherry-pick procedure — `PROVENANCE.md` in-tree, per-delta category-tagged entries, five-step adoption discipline | Accepted |
 | [019](decisions/019-mechanism-handle-surfaces.md) | Mechanism-handle surfaces — handle traits (`Queue`/`StreamHandle`/`Outbox`/`Lock`/`JobHandle`), `Job`/`Schedule` shapes, `worker_id` identity, core `StopToken` | Accepted |
 | [020](decisions/020-enqueue-opt-semantics-and-bridges.md) | Enqueue-option semantics — delay/run_at precedence, relative `expires`, scheduler stamp source, serde_json payload encoding | Accepted |
+| [021](decisions/021-tx-reads-and-value-shape-fixes.md) | Third review round — tx-read methods on `TxHandle`, `Job.claimed_at`, `schedule()` queue-argument validation, drop = rollback, receiver close/error arms | Accepted |
 
 ## Open Questions
 
@@ -83,10 +84,12 @@ depth — [ADR-015](decisions/015-streams-depth.md)), ~~OQ-10~~
 (fork follow-through — provenance register + cherry-pick procedure,
 [ADR-018](decisions/018-provenance-register-and-cherry-picks.md)).
 
-No deferred OQs. With the question set closed (and the 2026-10-06
-second review round resolving its findings directly as ADR-019/ADR-020
-rather than as new OQs), Phase 1 moves to architecture review closure
-and the implementation-phase gates.
+No deferred OQs. The question set closed with OQ-11 (2026-10-06); the
+2026-10-06 second review round and the 2026-10-07 third review round
+resolved their findings directly as ADR-019/ADR-020 and
+[ADR-021](decisions/021-tx-reads-and-value-shape-fixes.md)
+respectively, rather than as new OQs. Phase 1 moves to architecture
+review closure and the implementation-phase gates.
 
 ## Document Lifecycle