gauntlet 2026-05-02: smoke chain + per-component scrum + parity probe

Production-readiness gauntlet exploiting the dual Rust/Go
implementation as a measurement instrument.

## Phase 1 — Full smoke chain
21/21 PASS in ~60s. Substrate intact across the full service surface.

## Phase 2 — Per-component scrum (token-volume fix)
Prior wave (165KB diff): Kimi 62 tokens out, Qwen 297 → no useful
analysis. This wave splits today's commits into 4 focused bundles
(36-71KB each):
  c1 validatord (46KB) → 0 convergent / 11 distinct
  c2 vectord substrate (36KB) → 0 convergent / 10 distinct
  c3 materializer (71KB) → 0 convergent / 6 distinct (Opus emitted
                           a BLOCK then self-retracted in same response)
  c4 replay (45KB) → 0 convergent / 10 distinct

Reviewer engagement vs prior wave: Kimi went 62 → ~250 tokens out
once bundles dropped below 60KB.

scripts/scrum_review.sh hardening:
  * Diff-size guard (warn >60KB, hard-fail >100KB,
    SCRUM_FORCE_OVERSIZE=1 override)
  * Tightened prompt — file path must appear EXACTLY as in diff
    so post-processor can grep WHERE: lines reliably
  * Auto-tally step dedupes by (reviewer, location); convergence
    counts distinct lineages (closes the prior `opus+opus+opus`
    false-convergence bug)

## Phase 3 — Cross-runtime validator parity probe (the headline finding)
scripts/cutover/parity/validator_parity.sh sends 6 identical
/v1/validate cases to Rust :3100 AND Go :4110, compares status+body.

Result: **6/6 status codes match · 5/6 body shapes diverge.**

Rust returns serde-tagged enum:   {"Schema":{"field":"x","reason":"y"}}
Go returns flat exported-fields:  {"Kind":"schema","Field":"x","Reason":"y"}

Both round-trip inside their own runtime; a caller swapping one for
the other would break parsing silently. Captured as new _open_ row
in docs/ARCHITECTURE_COMPARISON.md decisions tracker.

This is the "use the dual-implementation as a measurement instrument"
return — single-repo scrums can't catch this class of cross-runtime
drift.

## Phase 4 — Production assessment
ship-with-known-gap. Validator wire-format gap is documented, not
regressed. ~50 LOC future fix on Go side (custom MarshalJSON on
ValidationError to match Rust's serde shape).

Persistent stack config (/tmp/lakehouse-persistent.toml) gains
validatord on :3221 + persistent-validatord binary so operators
bringing up the persistent stack get the new daemon automatically.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

reports/cutover/gauntlet_2026-05-02/parity/validator_parity.md

@@ -0,0 +1,132 @@
+# Validator parity probe — Rust :3100 vs Go :4110
+
+**Date:** 2026-05-02T08:59:17Z
+**Rust gateway:** `http://127.0.0.1:3100`  ·  **Go gateway:** `http://127.0.0.1:4110`
+
+Identical `POST /v1/validate` request → both runtimes. Match
+= identical HTTP status + identical body (modulo `elapsed_ms`).
+
+| Case | Rust status | Go status | Status match | Body match |
+|---|---:|---:|:---:|:---:|
+| playbook_happy | 200 | 200 | ✓ | ✓ |
+| playbook_missing_fingerprint | 422 | 422 | ✓ | ✗ |
+| playbook_wrong_prefix | 422 | 422 | ✓ | ✗ |
+| playbook_empty_endorsed | 422 | 422 | ✓ | ✗ |
+| playbook_overfull | 422 | 422 | ✓ | ✗ |
+| fill_phantom | 422 | 422 | ✓ | ✗ |
+
+**Tally:** 1 match · 5 diff (out of 6 cases)
+
+## Divergences
+
+<details><summary>DIFF — `playbook_missing_fingerprint`</summary>
+
+**Rust** (HTTP 422):
+```json
+{
+  "Schema": {
+    "field": "fingerprint",
+    "reason": "missing — required for Phase 25 validity window"
+  }
+}
+```
+
+**Go** (HTTP 422):
+```json
+{
+  "Field": "fingerprint",
+  "Kind": "schema",
+  "Reason": "missing — required for Phase 25 validity window"
+}
+```
+
+</details>
+
+<details><summary>DIFF — `playbook_wrong_prefix`</summary>
+
+**Rust** (HTTP 422):
+```json
+{
+  "Schema": {
+    "field": "operation",
+    "reason": "expected `fill: ...` prefix, got \"sms_draft: hello\""
+  }
+}
+```
+
+**Go** (HTTP 422):
+```json
+{
+  "Field": "operation",
+  "Kind": "schema",
+  "Reason": "expected `fill: ...` prefix, got \"sms_draft: hello\""
+}
+```
+
+</details>
+
+<details><summary>DIFF — `playbook_empty_endorsed`</summary>
+
+**Rust** (HTTP 422):
+```json
+{
+  "Completeness": {
+    "reason": "endorsed_names must be non-empty"
+  }
+}
+```
+
+**Go** (HTTP 422):
+```json
+{
+  "Field": "",
+  "Kind": "completeness",
+  "Reason": "endorsed_names must be non-empty"
+}
+```
+
+</details>
+
+<details><summary>DIFF — `playbook_overfull`</summary>
+
+**Rust** (HTTP 422):
+```json
+{
+  "Completeness": {
+    "reason": "endorsed_names (3) exceeds target_count × 2 (2)"
+  }
+}
+```
+
+**Go** (HTTP 422):
+```json
+{
+  "Field": "",
+  "Kind": "completeness",
+  "Reason": "endorsed_names (3) exceeds target_count × 2 (2)"
+}
+```
+
+</details>
+
+<details><summary>DIFF — `fill_phantom`</summary>
+
+**Rust** (HTTP 422):
+```json
+{
+  "Consistency": {
+    "reason": "fills[0].candidate_id \"W-PHANTOM-NEVER-EXISTS\" does not exist in worker roster"
+  }
+}
+```
+
+**Go** (HTTP 422):
+```json
+{
+  "Field": "",
+  "Kind": "consistency",
+  "Reason": "fills[0].candidate_id \"W-PHANTOM-NEVER-EXISTS\" does not exist in worker roster"
+}
+```
+
+</details>