M4 disability gate flip: lock ratified 2026-07-12 (ceremony record inside) (#159)

* M4 gate lock flip: ratified thresholds live

Add gate_m4 (the M4 DI disability gate) as a NEW LOCKED top-level gate
(unlike gate_2b/2c, it had no pre-existing unlocked stub). The full lock
ceremony ran on PR #153 (floor runs/m4_gate_floors_v1.json): round-1 AMEND
BEFORE LOCK (comment 4950447491, findings 1-6 / fixes A-F) -> fixes
(comment 4950571161, 05d8292 + merge 45bbabe) -> verification AMEND
metadata-only, the PR body (comment 4950648191) -> body amendment executed
(comment 4950660426) -> ratifying squash merge 0fa4a29, under the standing
campaign directive of 2026-07-07.

gates.yaml gate_m4 (kind anchor_based): the 12-cell surface (8 internal
mixed-k -- flow incidence/recovery @k=3 + prevalence.50-59 STOCK @k=4 -- + 4
concept-bridged anchor cells at the pinned >=3 sigma margin), tolerances
machine-derived as round(floor mean + k*sd, 3) from the FROZEN floor and
capped at ln(1.5), the 24 report-only cells (all tolerance_above_t_max), the
K=20 mean-over-draws protocol (5200+k) + fresh_run schema [20,8,5], the
k_selection rule (k=2 flow OC 0.2901 / k=3 flow OC 0.9717 / stock k=4), the
in-repo sha-pinned di_asr_2023 anchor (reported, never gated), the
ceremony_record (four comment ids + ratified-by-merge 0fa4a29 + delegated
authority) and the 2026-07-12-m4-gate-lock history entry. ZERO threshold
movement vs the ratified floor: the frozen artifact is READ, never rewritten.
The five verification flip-time notes are implemented.

Locked-hot bindings extend tests/test_gates_derivations.py (21 tests:
tolerance derivations, 12/24 partition set-equality, OC 0.9408/0.9689
recompute, mixed-k + k_selection, anchor margins + epsilon-tilt failure,
protocol equality, D1 SUBSET master-compare, history). The floor's own
gates.yaml guard (test_m4_gate_derivations.py) flips to assert gate_m4
locked. The legacy manifest's contract_revision + gates.yaml entry track the
flip via --transition (41 frozen entries byte-identical). Tier manifest
artifact 744 -> 765 (CI-equivalent collection, openpyxl present), total
2,422.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

* Fix gate_m4 weight_definition to the ratified start-wave weight (flip referee finding 1); annotate precedent_oc_band

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

---------

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

Author: MaxGhenis

gates.yaml

@@ -1,12 +1,12 @@
 {
   "schema_version": "legacy_manifest.v1",
   "generated_at_commit": "747966cd7426a2a2292ce3dd093a8fe65d9a9351",
-  "contract_revision": "890aa394ff317d4ae133ecbb2adaca860935bcf6",
+  "contract_revision": "48dd85acdc1490b4177236d2b066a7c748c0a95b",
   "entries": [
     {
       "path": "gates.yaml",
-      "sha256": "3990e15af110b5fbd4caa897c004219053fff0aa741a4e15ab8c3b1eb9b1147e",
-      "n_bytes": 168354,
+      "sha256": "8fd1f189b7b1f9da2d508c7c04a7864a86364c7e1a31a4a1b4fe4b7c61c570be",
+      "n_bytes": 217270,
       "originating_commit": "84a6721b686cef465150212432d8fc517dd53122"
     },
     {

runs/legacy_manifest_v1.json

@@ -34,8 +34,8 @@ pytest --collect-only -q -m oracle_policyengine | tail -1
 | Tier | Tests at HEAD |
 |---|---:|
 | `unit` | 199 |
-| `artifact` | 744 |
+| `artifact` | 765 |
 | `integration_psid` | 782 |
 | `reproduction_legacy` | 520 |
 | `oracle_policyengine` | 156 |
-| **Total** | **2,401** |
+| **Total** | **2,422** |