[AZ-1133] Add perf gate preflight before PT-01

Probe API reachability after JWT mint; exit 7 with compose-up
instructions when the perf stack is down. Document in environment
and containerization guides.

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

_docs/03_implementation/batch_01_cycle16_report.md

@@ -0,0 +1,32 @@
+# Batch Report
+
+**Batch**: 1
+**Tasks**: AZ-1133_perf_gate_preflight
+**Date**: 2026-06-26
+
+## Task Results
+
+| Task | Status | Files Modified | Tests | AC Coverage | Issues |
+|------|--------|---------------|-------|-------------|--------|
+| AZ-1133 | Done | 3 files | curl probe pass | 4/4 ACs covered | None |
+
+## AC Test Coverage: All covered
+
+| AC | Evidence |
+|----|----------|
+| AC-1 | `preflight_api_reachable` called after JWT mint, before PT-01 banner in `run-performance-tests.sh` |
+| AC-2 | Isolated curl probe to `localhost:19999` → `curl_exit=7`; script prints compose-up and `exit 7` |
+| AC-3 | HTTP response path proceeds (any non-zero curl exit only triggers preflight fail) |
+| AC-4 | `environment.md` + `containerization.md` updated |
+
+## Code Review Verdict: PASS
+
+- Preflight uses same `CURL_OPTS` / `AUTH_HEADER` as PT-01
+- `set +e` / `set -e` scoped around probe — does not weaken global `pipefail`
+- Exit code 7 reserved for unreachable API per task spec
+- Docs cross-link preflight + exit 7
+
+## Auto-Fix Attempts: 0
+## Stuck Agents: None
+
+## Next Batch: All tasks complete