Review #007: fix YAML frontmatter — unquoted colon in reviewer value broke parsing

docs/reviews/007-coverage-audit.md

@@ -21,7 +21,7 @@ reviewed_artifacts:
   - tests/engine_integration.rs
   - docs/reviews/006-implementation-review-030.md (post-fix coverage re-check)
 tool: cargo-llvm-cov 0.8.4 (--release, per-line text) + manual classification of every uncovered production line + disposable probe tests (run in-session, then deleted)
-reviewer: post-review-#006 coverage audit (session request: "check test coverage for weak spots, meaningful tests, non-happy-path posture")
+reviewer: post-review-#006 coverage audit (session request — check test coverage for weak spots, meaningful tests, non-happy-path posture)
 ---
 
 # Review #007 — Post-#006 Coverage Audit