STATE_OF_PLAY: Rust is not maintenance-only as of 2026-05-02

Frames the Rust system accurately — it's receiving parity work +
infrastructure (Lance gauntlet, sidecar drop, observability parity),
not just security fixes. Points readers at lakehouse/STATE_OF_PLAY.md
+ docs/ARCHITECTURE_COMPARISON.md for the cross-runtime view.

Also commits today's parity probe report regenerations (5/5 still
32/32 post-Lance work).

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

STATE_OF_PLAY.md

@@ -3,7 +3,7 @@
 **Last verified:** 2026-05-02 ~11:30 CDT
 **Verified by:** **production-readiness gauntlet** — 21/21 smoke chain green, per-component scrum across 4 bundles, **3 cross-runtime parity probes all green post-fix** (validator: **6/6 match** after wire-format alignment shipped; materializer: 2/2 after omitempty fix; extract_json: 12/12). All findings surfaced by the parity probes have been actioned. Disposition: `reports/cutover/gauntlet_2026-05-02/disposition.md`.
 
-> **Read this FIRST.** When the user says "we're working on lakehouse," default to the Go rewrite (this repo); the Rust legacy at `/home/profit/lakehouse/` is maintenance-only. If memory contradicts this file, this file wins. Update it when something is verified working — not when a phase finishes.
+> **Read this FIRST.** When the user says "we're working on lakehouse," default to the Go rewrite (this repo) but ASK if ambiguous — the Rust system at `/home/profit/lakehouse/` is also receiving real work as of 2026-05-02 (Lance backend hardening, observability parity, sidecar drop — see `lakehouse/STATE_OF_PLAY.md`). The cross-runtime decisions tracker at `docs/ARCHITECTURE_COMPARISON.md` is the single source of truth for what's open across both. If memory contradicts this file, this file wins. Update it when something is verified working — not when a phase finishes.
 
 ---
 
@@ -198,7 +198,7 @@ Verbatim verdicts at `reports/scrum/_evidence/2026-04-30/verdicts/`. Disposition
 
 ### Session frame (don't redo)
 
-- The Rust legacy is **maintenance-only** until Go reaches feature parity. Don't propose ports of components already shipped here.
+- The Rust system is **NOT maintenance-only** as of 2026-05-02 — it's receiving parity work + infrastructure (Lance gauntlet, sidecar drop, observability parity). Don't propose ports of components already shipped on the Go side, but do expect Rust commits to land in parallel for cross-runtime fabric.
 - The matrix indexer **5/5 components** are shipped. Don't propose to "build the matrix indexer" — it's done.
 - The 5-loop substrate's load-bearing gate is **PASSED**. v3 (`154a72e`) showed 6/6 paraphrase recovery via Shape B. Don't propose to "test if the playbook learns" — it does.
 - **Shape B is the playbook stance now.** When `use_playbook=true`, both `ApplyPlaybookBoost` (re-rank in place) AND `InjectPlaybookMisses` (insert recorded answers not in regular top-K) run. Don't revert to boost-only; v2 proved that path can't recover paraphrase queries.

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

@@ -1,6 +1,6 @@
 # /v1/embed cross-runtime parity probe
 
-**Date:** 2026-05-02T11:28:19Z
+**Date:** 2026-05-03T03:13:12Z
 **Rust:** `http://127.0.0.1:3100/ai/embed`  ·  **Go:** `http://127.0.0.1:4110/v1/embed`
 **Model:** `nomic-embed-text` (forced — overrides each side's default)
 **Match metric:** cosine similarity ≥ `0.99999`

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

@@ -1,6 +1,6 @@
 # extract_json parity probe — Rust vs Go
 
-**Date:** 2026-05-02T11:24:21Z
+**Date:** 2026-05-03T03:13:10Z
 **Rust helper:** `/home/profit/lakehouse/target/release/parity_extract_json` (links live `gateway::v1::iterate::extract_json`)
 **Go helper:** `./bin/parity_extract_json_go` (links live `internal/validator.ExtractJSON`)
 

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

@@ -1,6 +1,6 @@
 # Materializer parity probe — Bun vs Go
 
-**Date:** 2026-05-02T11:24:21Z
+**Date:** 2026-05-03T03:13:11Z
 **Bun:** `/home/profit/lakehouse/scripts/distillation/build_evidence_index.ts`
 **Go:**  `./bin/materializer`
 

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

@@ -1,6 +1,6 @@
 # session_log parity probe — Rust gateway vs Go validatord
 
-**Date:** 2026-05-02T11:24:21Z
+**Date:** 2026-05-03T03:13:10Z
 **Rust helper:** `/home/profit/lakehouse/target/release/parity_session_log`
 **Go helper:** `./bin/parity_session_log_go`
 

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

@@ -1,6 +1,6 @@
 # Validator parity probe — Rust :3100 vs Go :4110
 
-**Date:** 2026-05-02T11:24:15Z
+**Date:** 2026-05-03T03:13:05Z
 **Rust gateway:** `http://127.0.0.1:3100`  ·  **Go gateway:** `http://127.0.0.1:4110`
 
 Identical `POST /v1/validate` request → both runtimes. Match