[AZ-1133] Cycle 16 closeout — traceability, retro, state

Test-spec sync, doc ripple, retrospective; autodev advances to cycle 17.

Co-authored-by: Cursor <cursoragent@cursor.com>

_docs/02_document/ripple_log_cycle16.md

@@ -0,0 +1,19 @@
+# Ripple Log — Cycle 16
+
+**Task**: AZ-1133 (perf gate preflight)
+**Date**: 2026-06-26
+
+## Files updated (Step 13)
+
+| File | Change |
+|------|--------|
+| `scripts/run-performance-tests.sh` | Added `preflight_api_reachable` (implementation) |
+| `_docs/02_document/tests/environment.md` | Preflight + exit 7 in Performance tests section |
+| `_docs/02_document/deployment/containerization.md` | Preflight cross-link under perf overlay |
+| `_docs/02_document/tests/performance-tests.md` | New § Preflight before PT-01 |
+| `_docs/02_document/tests/traceability-matrix.md` | AZ-1133 AC-1..AC-4 rows + cycle 16 summary |
+
+## Skipped ripples
+
+- No module-layout / architecture / contract version bumps (tooling-only)
+- No OpenAPI / blackbox scenario additions (harness preflight only)