docs(docs): add frontmatter to test plans, test reports, and audits

Standardized YAML frontmatter on 7 files across docs/test-plans/,
docs/test-reports/, and docs/audits/.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docs/audits/README.md

@@ -1,3 +1,12 @@
+---
+title: "Architecture Audits"
+description: "Index and methodology reference for adversarial two-round architecture audits. Documents the review format, scope, reviewer roles, and audit history."
+type: audit
+status: active
+created: 2026-02-11
+updated: 2026-02-11
+---
+
 # Architecture Audits
 
 ## Audit Pattern: Adversarial Two-Round Review with Code Review

docs/audits/architecture-review-2026-02-11.md

@@ -1,3 +1,12 @@
+---
+title: "Architecture Review — Sprint 1"
+description: "Full adversarial two-round architecture audit by Tyre and Troblum covering all 40 confirmed decisions, implementation, and risk profile. Architecture rated GREEN; knowledge graph and observer pipeline identified as underspecified critical systems."
+type: audit
+status: archived
+created: 2026-02-11
+updated: 2026-03-05
+---
+
 # Architecture Review Audit — The Settled Reach
 
 **Date:** 2026-02-11