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/proxy/routes.py

@@ -93,11 +93,13 @@ def build_proxy_router(cfg: ProxyConfig, pool, settings_provider=None) -> APIRou
                 from gateway.sense.config import build_sense_config
                 from gateway.sense.grader import Grader
                 from gateway.sense.observer import get_observer
+                from gateway.sense.promotion import PromotionTable
                 from gateway.sense.store import SenseStore
                 scfg = build_sense_config(settings_provider().to_dict())
                 if scfg.enabled and scfg.mode == "live":
                     sstore = SenseStore.init_db(scfg.db_path)
-                    grader = Grader(scfg, sstore, get_observer(sstore))
+                    grader = Grader(scfg, sstore, get_observer(sstore),
+                                    promotion=PromotionTable(sstore))
                     qtext = "\n".join(str(m.get("content") or "")
                                       for m in (body.get("messages") or []))
                     d = await grader.decide(qtext or str(body.get("model") or ""),
@@ -114,14 +116,17 @@ def build_proxy_router(cfg: ProxyConfig, pool, settings_provider=None) -> APIRou
             resp = await _run_chat(body, dict(request.headers), ctx, cfg, ledger, pool)
             if tier_used:
                 resp.headers["x-campus-tier"] = tier_used
-                # T1 审计抽样（§9.4）：按 review.sample_rate 入队人工核
+                # T1 审计抽样（§9.4）：按 review.sample_rate 入队人工核；
+                # promo 标签供人工 verdict 回填晋升表（T-X5）
                 try:
                     import random as _random
+                    from gateway.sense.promotion import promotion_label
                     rate = float(load_config().get("review", {}).get("sample_rate", 0.1))
                     if _random.random() < rate:
                         get_review().enqueue(
                             request_id + "-sense", str(body.get("model") or "proxy"),
-                            "(sense T1 审计抽样)", tags=["sense_t1"],
+                            "(sense T1 审计抽样)",
+                            tags=["sense_t1", "promo:" + promotion_label("proxy", "")],
                             reason="sense_audit")
                 except Exception:
                     pass