ADR-019/020: second review round — handle surfaces, enqueue semantics, payload bridge + mechanical fixes

ADR-019: mechanism-handle traits pinned (Queue/StreamHandle/Outbox/
Lock/JobHandle), Job/Schedule struct shapes, worker_id claimant
identity, core StopToken — closes the 'pin at implementation' residue
before ADR-017's amend-in-place window terminates at first release.

ADR-020: delay-wins-over-run_at precedence (honker parity), relative
expires, scheduler-fired stamps from derived queue defaults, serde_json
byte-level payload encoding.

Mechanical: overview/engine-postgres ADR tables completed through 020,
core-contract Errors section re-framed to class-1, ADR-014 sketch
annotated with publish_with_key_tx, ADR-015 status dated, reserved-
namespace kinds list normalized to six kinds, redrive gate wording
aligned, broken link fixed, StopToken deferral superseded in ADR-009.

docs/architecture/open-questions.md

@@ -42,6 +42,18 @@ entries;
 five-step cherry-pick procedure recorded at adoption). **The Phase 1
 question set is closed** — no open OQs remain; Phase 1 moves to
 architecture review and the implementation-phase gates.
+**Second review round (2026-10-06, pre-decomposition):** the review
+found no *new* open questions — every finding was decidable from
+decided material, so it resolved directly as
+[ADR-019](decisions/019-mechanism-handle-surfaces.md) (handle-trait
+surfaces, `Job`/`Schedule` shapes, claimant identity, `StopToken` —
+closing the "pin at implementation" residue before ADR-017's class-1
+window ends at first release) and
+[ADR-020](decisions/020-enqueue-opt-semantics-and-bridges.md)
+(`delay`/`run_at` precedence, relative `expires`, scheduler-fired
+jobs' stamp source, the serde_json payload encoding bridge), plus
+mechanical fixes (ADR index staleness in overview/engine-postgres,
+stale wording, framing drift).
 
 Resolved questions stay listed with their resolution; they are not
 deleted.
@@ -137,7 +149,7 @@ narrowed to the pinning work its own record already scoped.)*
   surface; the contract is the trait it returns. (7) Locks guarantee
   row added to ADR-006's table (TTL-bounded mutual exclusion, silent
   expiry); the scheduler row is explicitly transferred to OQ-09's
-  resolution. A verification   backlog (core-contract.md §Verification
+  resolution. A verification backlog (core-contract.md §Verification
   backlog) tracks the one-engine-pinned properties.
 - **Cross-references**: OQ-01, OQ-10 (resolved —
   [ADR-017](decisions/017-contract-versioning.md), the discipline