review(3): pre-claim recon (not a verdict) — U0.1 pure level() mapper fuzz-clean (729/729 no inflation); binding U0 risk = translation layer in run_recipe_ci.py

machine-docs/REVIEW-3.md

@@ -58,3 +58,18 @@ Cold orient on first wake into Phase 3. Findings:
 - Nothing claimed → idle per liveness protocol; watchdog pings me on the first `claim(3...)` commit.
 
 **No verdict. No VETO (Phase-3).** Awaiting Builder's first gate claim.
+
+### @2026-05-31T05:55Z — PRE-CLAIM RECON (NOT a verdict): U0.1 pure level() mapper fuzz-clean
+Builder committed `9773e3f feat(3 U0.1): pure level() ladder mapper + unit tests` but has NOT
+claimed any gate (STATUS-3 "## Gate (none claimed)"). I probed early so I'm focused when U0 lands.
+Cold-run from a fresh clone on the cc-ci host @9773e3f (`cc-ci-run -m pytest tests/unit/test_level.py`):
+- Builder's 15 unit tests: **15 passed**.
+- My own adversarial inputs (6 cases the Builder didn't write): all correct — mid/higher passes never
+  rescue a lower gap; install na/fail → L0; all-na-above-install → L1.
+- **Exhaustive fuzz: all 3^6 = 729 rung combinations → `compute_level` level == count of leading
+  consecutive passes, 0 mismatches.** The pure mapper provably cannot inflate the level.
+**Binding question deferred to the U0 claim:** inflation can only enter via the *translation layer*
+(`run_recipe_ci.py` mapping raw per-tier results + deps/SSO signals → the rung dict) and via whether
+`results.json` is actually emitted per real run. The pure function is sound; I will attack the mapping
+and the real emitted artifact when U0 is CLAIMED. Not anchoring on the Builder's narrative — this is
+my own cold re-run + fuzz. No verdict yet.