Implementation plan: wave-based decomposition; waves 1-2 decomposed (11 tasks)

docs/plans/implementation.md records the wave structure (core ->
substrate fork || pg engine -> sqlite engine -> contract suite ->
release), the decided points (contract-suite layout = option (a),
engine-tests vs equivalence-suite split, no CI, mem-engine/fuzzing
deferrals surfaced), and the review-gate rhythm.

Wave 1 (foundations): workspace scaffold, core errors/validation,
value types, trait surface, contract-suite scaffold (+ADR-022),
review gate.
Wave 2 (substrate fork): fork scaffold/provenance, connection+watcher
port, queue-op re-derivation on contract v1, provenance/floor close,
review gate.

tasks/review-wave-2.md

@@ -0,0 +1,68 @@
+---
+id: review-wave-2
+name: Review gate — wave 2 (substrate fork)
+status: pending
+depends_on: [fork-provenance-and-floor]
+scope: narrow
+risk: low
+impact: component
+level: review
+tags: [wave-2, review]
+---
+
+## Description
+
+Review the substrate fork before wave 3 builds the engine on it.
+Primary lens: **diff reviewability against the lineage** (ADR-012 §3's
+fidelity posture — the fork's economics rest on future cherry-picks
+staying cheap) and **the defect class staying out** (the fork's
+reason for existing).
+
+Check:
+
+- **Fidelity**: the kept half's module structure and internal names
+  match the lineage; renames confined to the table family and hygiene
+  deltas; the diff vs. `/workspace/honker` @ `f4e53c6` contains
+  nothing unregistered.
+- **Port deltas**: W-1/W-2/dead-man's-switch applied as decided; no
+  other behavior changes smuggled in; W-4 (RW watcher connection)
+  deliberately kept.
+- **Drops**: cron, experimental watchers + their optional deps,
+  rate-limit/result tables, superseded queue functions — absent, and
+  their absence registered.
+- **Re-derivation vs. ADR-010**: stamps land per §3a; the claim
+  statement's ordering and visibility semantics match §1–§2; the
+  validity predicate is uniform across ack/heartbeat/retry/fail;
+  savepoint hardening real (test-read it, don't trust the test name);
+  sweep covers both states; the curve/boundary arithmetic is *not* in
+  the substrate (contract-blind boundary — ADR-012 §2).
+- **Provenance**: register complete and accurate per ADR-018; license
+  notice correct.
+- **Family standards** in the substrate: sync only, no panics, no
+  error swallows, no comments (doc comments fine).
+- **Gates**: full engine-crate test suite, clippy `-D warnings`, fmt
+  clean.
+
+## Acceptance Criteria
+
+- [ ] Lineage diff reviewed; every divergence registered or fixed
+- [ ] Re-derivation matches ADR-010's pinned semantics (spot-checked
+      against the ADR text, not just the tests)
+- [ ] Provenance register accurate
+- [ ] All gates green
+- [ ] Findings recorded; wave 3 decomposition may proceed
+
+## References
+
+- docs/architecture/decisions/012-forked-substrate-design.md §3
+- docs/architecture/decisions/010-queue-semantics-depth.md
+- docs/architecture/decisions/018-provenance-register-and-cherry-picks.md
+- docs/plans/implementation.md (Review gates)
+
+## Notes
+
+> To be filled by implementation agent
+
+## Summary
+
+> To be filled on completion