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

docs/architecture/overview.md

@@ -1,6 +1,6 @@
 ---
 status: draft
-last_updated: 2026-10-06 (ADR-019/020 — handle surfaces, enqueue semantics, payload bridge)
+last_updated: 2026-10-07 (ADR-021 — third review round: tx reads, value-shape fixes, schedule queue validation, drop=rollback, receiver arms)
 ---
 
 # alkstore — Overview
@@ -84,6 +84,7 @@ Per [ADR-002](decisions/002-feature-scope.md):
 | [018](decisions/018-provenance-register-and-cherry-picks.md) | Substrate provenance register and cherry-pick procedure (`PROVENANCE.md` in-tree, per-delta entries) | Accepted |
 | [019](decisions/019-mechanism-handle-surfaces.md) | Mechanism-handle surfaces (handle traits, `Job`/`Schedule` shapes, `worker_id`, `StopToken`) | Accepted |
 | [020](decisions/020-enqueue-opt-semantics-and-bridges.md) | Enqueue-option semantics (delay/run_at, expires, scheduler stamp source, 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 |
 
 ## Non-goals