feat(proxy): T-X11 采纳 cortiq shadow 旁路评审——live T1 本地应答异步云端评审喂晋升表

- routes：live 分流 T1 响应后按 sample_rate 采样旁路——premium 条目以评审提示词
  给本地答案打 PASS/FAIL，经 PromotionTable.observe 写入 T-X5 晋升表
  （打通晋升质量信号的自动来源，夜间 labeler 之外的实时通路）
- 零客户端延迟：asyncio.create_task 旁路 + wait_for 超时 + Semaphore(2) 并发上限；
  上游故障/解析失败记 ERROR，不算 FAIL（评审器不可用不惩罚本地模型）；
  仅非流式响应采样（流式无同步答案文本），默认关闭（sense.shadow_review.enabled）
- 模块级计数字典 sampled/pass/fail/error + reset_shadow_review_stats() 测试钩子
- 新增 tests/test_shadow_review.py 5 项（默认关/条目选取/PASS-FAIL-ERROR 解析/
  晋升表喂入/关闭态零副作用），全假上游不依赖真实模型

tests/test_shadow_review.py

@@ -0,0 +1,128 @@
+"""shadow 旁路评审单元测试（T-X11，采纳 cortiq shadow bypass 设计）。
+
+全部走 monkeypatch 假上游，不依赖真实模型/API key。
+"""
+import asyncio
+import json
+
+import pytest
+
+import gateway.proxy.routes as R
+from gateway.proxy.routes import (_grade_answer, _pick_review_entry,
+                                  _shadow_review_settings,
+                                  reset_shadow_review_stats)
+from gateway.sense.promotion import PromotionTable, promotion_label
+
+
+@pytest.fixture(autouse=True)
+def _reset():
+    reset_shadow_review_stats()
+    yield
+    reset_shadow_review_stats()
+
+
+def _fake_upstream(responses):
+    """构造假 upstream_stream：按调用顺序吐预定 verdict 文本（SSE 形态）。"""
+    calls = {"n": 0}
+
+    def _stream(body, entry, sink, chain):
+        async def gen():
+            idx = min(calls["n"], len(responses) - 1)
+            calls["n"] += 1
+            verdict = responses[idx]
+            chunk = {"choices": [{"delta": {"content": verdict}}]}
+            yield (f"data: {json.dumps(chunk)}\n\n").encode("utf-8")
+            yield b"data: [DONE]\n\n"
+        return gen()
+
+    return _stream, calls
+
+
+def _entry(tier="premium", model="cloud-x"):
+    return {"id": "e1", "enabled": True, "backend": "openai",
+            "base_url": "http://127.0.0.1:9/v1", "model": model, "tier": tier}
+
+
+def test_settings_default_disabled_and_clamped():
+    """默认关闭；采样率/超时非法值被夹取。"""
+    s = _shadow_review_settings({})
+    assert s["enabled"] is False and s["sample_rate"] == 0.1
+    assert _shadow_review_settings({"sense": {"shadow_review": {
+        "enabled": True, "sample_rate": 5, "timeout_s": -3}}})["sample_rate"] == 1.0
+    assert _shadow_review_settings({"sense": {"shadow_review": {
+        "enabled": True, "timeout_s": -3}}})["timeout_s"] == 1.0
+
+
+def test_pick_review_entry_prefers_tier():
+    """评审条目优先指定档位，缺失时回退任意启用条目。"""
+    pool_entries = [_entry("budget", "b1"), _entry("premium", "p1")]
+    class _P:
+        @staticmethod
+        def usable_entries():
+            return list(pool_entries)
+    assert _pick_review_entry(_P, "premium")["model"] == "p1"
+    assert _pick_review_entry(_P, "local")["model"] in ("b1", "p1")
+
+
+def test_grade_answer_parses_pass_fail_and_error(monkeypatch):
+    """PASS/FAIL 解析；上游异常回 ERROR 而非抛出。"""
+    fake, calls = _fake_upstream(["PASS", "FAIL"])
+    monkeypatch.setattr(R, "upstream_stream", fake)
+    e = _entry()
+    assert asyncio.run(_grade_answer(e, "问", "答", "cloud-x", 5)) == "PASS"
+    assert asyncio.run(_grade_answer(e, "问", "答", "cloud-x", 5)) == "FAIL"
+
+    def _boom(*a, **k):
+        async def gen():
+            raise RuntimeError("上游炸了")
+            yield b""  # pragma: no cover
+        return gen()
+    monkeypatch.setattr(R, "upstream_stream", _boom)
+    assert asyncio.run(_grade_answer(e, "问", "答", "cloud-x", 5)) == "ERROR"
+    assert calls["n"] == 2
+
+
+def test_shadow_review_task_feeds_promotion(tmp_path, monkeypatch):
+    """PASS/FAIL 写入晋升表（observe 计数），ERROR 只计错误不进通过率。"""
+    from gateway.sense.store import SenseStore
+    sstore = SenseStore.init_db(str(tmp_path / "sense.sqlite3"))
+    promo = PromotionTable(sstore, now=lambda: 1_000_000.0)
+    label = promotion_label("proxy", "")
+
+    fake, _ = _fake_upstream(["PASS", "PASS", "FAIL", "垃圾输出"])
+    monkeypatch.setattr(R, "upstream_stream", fake)
+    entry = _entry()
+    sd = {"sense": {"shadow_review": {"enabled": True, "sample_rate": 1.0}}}
+
+    async def _run():
+        for _ in range(4):
+            await R._shadow_review_task("问题", "本地答案", _FixedPool(entry),
+                                        sd, promo)
+
+    asyncio.run(_run())
+    assert R._shadow_review_stats == {"sampled": 4, "pass": 2, "fail": 1,
+                                  "error": 1, "skipped_busy": 0}
+    row = sstore.get_promotion(label)
+    assert row["n_total"] == 3 and row["n_ok"] == 2  # ERROR 不进通过率
+
+
+class _FixedPool:
+    def __init__(self, entries):
+        self._e = entries if isinstance(entries, list) else [entries]
+
+    def usable_entries(self):
+        return list(self._e)
+
+
+def test_maybe_shadow_review_disabled_is_noop(monkeypatch):
+    """默认关闭：不建任务、不计采样。"""
+    class _SP:
+        @staticmethod
+        def to_dict():
+            return {"sense": {"shadow_review": {"enabled": False}}}
+
+    payload = json.dumps({"choices": [{"message": {"content": "本地答案"}}]}).encode()
+    resp = type("JR", (), {"body": payload})()
+    before = dict(R._shadow_review_stats)
+    R._maybe_shadow_review({}, resp, _FixedPool(_entry()), _SP, scfg=None)
+    assert R._shadow_review_stats == before