feat(sense): T-X5 云端评判晋升表×conformal 双闸门——本地档自动接管（采纳 cortiq promotion）

- gateway/sense/promotion.py：PromotionTable 状态机（candidate/promoted/demoted）
  * 晋升门：n_total>=n_min 且 通过率>=promote_lb 且 soak 浸泡期满足
  * 退化：promoted 期间通过率<demote_lb 自动降级；降级后可凭数据恢复
  * 一票否决：tier=T3 观察不进通过率统计，已晋升者立即降级
  * 持久化 sense_promotion 表（CREATE IF NOT EXISTS 幂等）
- grader：live 模式对已晋升标签的 T2 决策（无 T3 信号/非 fallback）升级 T1，
  hard_gates.promotion_applied 如实标注；T1/T3/fallback 路径不受影响
- 回填链路：T1 审计抽样带 promo:<label> 标签 -> 人工 verdict approve=ok
  经 /review/{id} 提交时回填晋升表（失败不影响审核主流程）
- 双闸门语义：conformal 阈值保证单条决策风险率，晋升表保证标签级接管节奏；
  collect 数据不足（n_min 未满）不晋升，全部迁移可经 T-X4 留痕审计

pytest 474 passed（T-X4 后 466 + 8）

gateway/sense/store.py

@@ -41,6 +41,14 @@ CREATE TABLE IF NOT EXISTS sense_decisions(
   candidate_scores TEXT NOT NULL DEFAULT '{}',
   rejected TEXT NOT NULL DEFAULT '[]');
 CREATE INDEX IF NOT EXISTS idx_dec_ts ON sense_decisions(ts);
+
+CREATE TABLE IF NOT EXISTS sense_promotion(
+  label TEXT PRIMARY KEY, n_total INTEGER NOT NULL DEFAULT 0,
+  n_ok INTEGER NOT NULL DEFAULT 0,
+  state TEXT NOT NULL DEFAULT 'candidate',
+  first_ts INTEGER NOT NULL DEFAULT 0,
+  promoted_ts INTEGER NOT NULL DEFAULT 0,
+  last_ts INTEGER NOT NULL DEFAULT 0);
 """
 
 
@@ -178,6 +186,30 @@ class SenseStore:
             out.append(d)
         return out
 
+    # ---------- 晋升表（T-X5：本地档自动接管的双闸门之一） ----------
+    def upsert_promotion(self, row: Dict[str, Any]) -> None:
+        with self._lock, self._connect() as conn:
+            conn.execute(
+                """INSERT OR REPLACE INTO sense_promotion
+                (label, n_total, n_ok, state, first_ts, promoted_ts, last_ts)
+                VALUES (?,?,?,?,?,?,?)""",
+                (row["label"], int(row.get("n_total", 0)),
+                 int(row.get("n_ok", 0)), str(row.get("state", "candidate")),
+                 int(row.get("first_ts", 0)), int(row.get("promoted_ts", 0)),
+                 int(row.get("last_ts", 0))))
+
+    def get_promotion(self, label: str) -> Optional[Dict[str, Any]]:
+        with self._lock, self._connect() as conn:
+            row = conn.execute(
+                "SELECT * FROM sense_promotion WHERE label = ?", (label,)).fetchone()
+        return dict(row) if row else None
+
+    def list_promotions(self) -> List[Dict[str, Any]]:
+        with self._lock, self._connect() as conn:
+            rows = conn.execute(
+                "SELECT * FROM sense_promotion ORDER BY last_ts DESC").fetchall()
+        return [dict(r) for r in rows]
+
     # ---------- 工件 ----------
     def register_artifact(self, version: str, kind: str, path: str,
                           metrics: Dict[str, Any], active: bool = False,