docs-frontmatter-cleanup: the 11 invalid last_updated frontmatter scalars quoted — double-quote convention applied uniformly (one escaped quote in phase-0.md), annotation prose verbatim; PyYAML sweep over docs/**/*.md + tasks/*.md reports 0 failures, taskgraph validate green (79 tasks); task status -> completed with Notes (recorded sweep command, date-scalar caveat) + Summary

docs/architecture/README.md

@@ -1,8 +1,8 @@
 ---
 status: draft
-last_updated: 2026-10-10 (ADR-024: the mem engine adopted as a third
+last_updated: "2026-10-10 (ADR-024: the mem engine adopted as a third
 engine — engine-mem.md added, ADR table row, index updated for the
-implementation phase)
+implementation phase)"
 ---
 
 # alkstore — Architecture

docs/architecture/core-contract.md

@@ -1,8 +1,8 @@
 ---
 status: draft
-last_updated: 2026-10-10 (ADR-024 — the mem engine joins the family;
+last_updated: "2026-10-10 (ADR-024 — the mem engine joins the family;
 the Store concept prose admits the engine-native constructor
-exception)
+exception)"
 ---
 
 # Core contract

docs/architecture/deployment.md

@@ -1,7 +1,7 @@
 ---
 status: draft
-last_updated: 2026-10-10 (ADR-024 — the mem engine joins the matrix:
-host row, connection budget, durability posture, wasm32 toolchain note)
+last_updated: "2026-10-10 (ADR-024 — the mem engine joins the matrix:
+host row, connection budget, durability posture, wasm32 toolchain note)"
 ---
 
 # Deployment

docs/architecture/engine-mem.md

@@ -1,13 +1,13 @@
 ---
 status: stable
-last_updated: 2026-10-10 (the wave-6 review gate passed: the
+last_updated: "2026-10-10 (the wave-6 review gate passed: the
 conformance read clean — three edge-domain fixes landed inline (the
 stream cursor read's `i64::MAX` overflow, `trim_to`'s horizon
 endpoint, the scheduler register-time interval overflow now rejecting
 with `InvalidSpec` like the SQLite register) plus scaffold-residue
 cleanup; the third column's 25-row set green under the current-thread
 flavor; the wasm32 gate + feature subset verified; the rider's arms
-verified)
+verified)"
 ---
 
 # Mem engine

docs/architecture/engine-postgres.md

@@ -1,6 +1,6 @@
 ---
 status: stable
-last_updated: 2026-10-10 (review-wave-5 gate: the verification backlog fully discharged in the version-stamped contract suite, green against this engine; spec flipped draft → stable)
+last_updated: "2026-10-10 (review-wave-5 gate: the verification backlog fully discharged in the version-stamped contract suite, green against this engine; spec flipped draft → stable)"
 ---
 
 # Postgres engine

docs/architecture/engine-sqlite.md

@@ -1,6 +1,6 @@
 ---
 status: stable
-last_updated: 2026-10-10 (review-wave-5 gate: the verification backlog fully discharged in the version-stamped contract suite, green against this engine; spec flipped draft → stable)
+last_updated: "2026-10-10 (review-wave-5 gate: the verification backlog fully discharged in the version-stamped contract suite, green against this engine; spec flipped draft → stable)"
 ---
 
 # SQLite engine

docs/architecture/overview.md

@@ -1,7 +1,7 @@
 ---
 status: draft
-last_updated: 2026-10-10 (ADR-024 — the mem engine joins the crate
-family as `alkstore-mem`; family/ADR tables updated)
+last_updated: "2026-10-10 (ADR-024 — the mem engine joins the crate
+family as `alkstore-mem`; family/ADR tables updated)"
 ---
 
 # alkstore — Overview

docs/architecture/queues.md

@@ -1,6 +1,6 @@
 ---
 status: draft
-last_updated: 2026-10-07 (ADR-021 + third-round follow-through: handle-form sweep_expired, ack_batch predicate, opts types)
+last_updated: "2026-10-07 (ADR-021 + third-round follow-through: handle-form sweep_expired, ack_batch predicate, opts types)"
 ---
 
 # Queues, scheduler, outbox — semantics depth