fix(r4-28v2): 双域阈值+检索模式免 LLM 免 rerank

TL 复测校准(TL 实测 175:垃圾 vector 0.32-0.34/正常 0.63+;垃圾 final 0.19-0.20):
1. score_gate 双域双常量:MIN_VECTOR_SCORE=0.45(QA_MIN_VECTOR_SCORE,向量域,
   Qdrant score_threshold 与 search 预筛);MIN_SOURCE_SCORE=0.25 保持(chat
   模式 final_score 后置过滤)。
2. pipeline answer():retrieval_only 无条件关 use_draft/use_planner(不看
   llm.available,search 模式绝不产生答案);use_bge_rerank 强制关(免 CPU
   rerank,性能根治);候选按 vector_score 排序直接输出且 final_score=
   vector_score(与 Qdrant 阈值同域)。
3. Qdrant score_threshold 仅在 retrieval_only 路径传入(direct_flow
   retriever 参数化,0.45);chat 不传保召回;v16_retriever 还原(r4-28 的
   0.25 全域阈值回退)。
4. 单测更新:search 无 LLM/无 rerank/0.45 滤 0.32 保 0.63/score 取 vector
   域/chat 不传阈值;chat final 域 0.25 语义不变。

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

agent/qa/src/rag/qa_v1_1_73/direct_flow_retriever.py

@@ -16,7 +16,6 @@ from src.rag.normalized_release import (
 )
 
 from .schemas import EvidenceItem, RetrievalHypothesis
-from .score_gate import min_source_score
 
 ALLOWED_QDRANT_COLLECTIONS = {
     "plant_srt_direct_v1_bge_m3_20260702",
@@ -201,17 +200,20 @@ class DirectFlowRetriever:
         }
         return merged, audit
 
-    def qdrant_search(self, query: str, limit: int) -> List[EvidenceItem]:
+    def qdrant_search(
+        self, query: str, limit: int, *, score_threshold: float | None = None
+    ) -> List[EvidenceItem]:
         try:
             vector = self.embed(query)
-            # 缺陷 #28（2026-09-11）：相关性下限双保险（与 pipeline
-            # _select_graph_balanced 同源同值，见 score_gate.py）。
+            # 缺陷 #28 回改 v2（2026-09-11）：向量域阈值仅 search/retrieval-only
+            # 路径传入（pipeline 传 QA_MIN_VECTOR_SCORE=0.45）；chat 模式 None
+            # 保召回，rerank 后由 final 域 MIN_SOURCE_SCORE=0.25 兜底。
             response = self.qdrant.query_points(
                 collection_name=self.collection,
                 query=vector,
                 limit=limit,
                 with_payload=True,
-                score_threshold=min_source_score(),
+                score_threshold=score_threshold,
             )
         except Exception:
             return []

agent/qa/src/rag/qa_v1_1_73/pipeline.py

@@ -43,7 +43,7 @@ from .question_decomposition import QuestionDecompositionPlanner
 from .query_builder import QueryBuilder
 from .reranker import BGEReranker
 from .schemas import EvidenceItem, HypothesisEntity, RetrievalHypothesis
-from .score_gate import min_source_score
+from .score_gate import min_source_score, min_vector_score
 from .soft_gate_policy import (
     LEGACY,
     doi_from_paper_id,
@@ -1255,7 +1255,11 @@ class QAV1Pipeline:
         use_qdrant = bool(retrieval_ablation.get("use_qdrant", True))
         use_neo4j = bool(retrieval_ablation.get("use_neo4j", True))
         use_graph_expansion = bool(retrieval_ablation.get("use_graph_expansion", True)) and use_neo4j
-        use_bge_rerank = bool(ablation.get("use_bge_rerank", True)) and self.config.enable_bge_rerank
+        use_bge_rerank = (
+            bool(ablation.get("use_bge_rerank", True))
+            and self.config.enable_bge_rerank
+            and not retrieval_only  # 回改 v2：search 免 CPU rerank（性能根治）
+        )
         use_final_llm = not retrieval_only
         graph_min_evidence = int(ablation.get("graph_min_evidence") or os.environ.get("QA_V115_GRAPH_MIN_EVIDENCE", "15"))
         answer_context_mode = str(ablation.get("answer_context") or "top30_plus_graph_chains")
@@ -1286,11 +1290,10 @@ class QAV1Pipeline:
             1.0, min(float(endpoint_path_time_budget_seconds or 5.0), 30.0)
         )
 
-        if retrieval_only and not self.llm.available:
-            # V1.1.711 supports retrieval-only operation. Without an LLM key,
-            # disable provisional drafting, structured planning, and final answer
-            # generation, but still return reranked top30 evidence and native
-            # Neo4j graph chains from the raw question.
+        if retrieval_only:
+            # 缺陷 #28 回改 v2（2026-09-11）：检索模式绝不产生答案——无条件
+            # 关闭草稿/规划/最终 LLM（不看 llm.available；LLM 调用纯浪费且
+            # 拖慢 search）。仍返回 top30 证据与 native 图链。
             use_draft = False
             use_planner = False
             use_final_llm = False
@@ -1392,7 +1395,15 @@ class QAV1Pipeline:
             "use_neo4j": use_neo4j,
             "use_graph_expansion": use_graph_expansion,
         }
-        if self.agentic_controller is not None:
+        if self.agentic_controller is None:
+            # 回改 v2（2026-09-11）：agentic_controller 禁用（含单测）时，
+            # 给确定性 plan——query_plan.agentic_plan 键不缺失。
+            agentic_plan = {
+                "vector_plan": {"enabled": bool(use_qdrant)},
+                "graph_plan": {"enabled": bool(use_neo4j)},
+                "plan_source": "deterministic_retrieval_only_plan",
+            }
+        elif self.agentic_controller is not None:
             try:
                 agentic_plan = self.agentic_controller.plan(
                     question,
@@ -1551,6 +1562,9 @@ class QAV1Pipeline:
                 hypothesis,
                 qdrant_top_k=qdrant_top_k,
                 graph_top_k=graph_top_k,
+                qdrant_score_threshold=(
+                    min_vector_score() if retrieval_only else None
+                ),
                 **direct_flow_switches,
             )
             timings["retrieval"] = time.perf_counter() - t0
@@ -1566,6 +1580,14 @@ class QAV1Pipeline:
         clustered_input, cluster_audit = build_clusters(ranked_input)
         if use_bge_rerank:
             ranked, rerank_audit = self._rerank(question, clustered_input)
+        elif retrieval_only:
+            # 回改 v2（2026-09-11）：search 免 BGE rerank，候选按 vector_score
+            # 排序直接输出，final_score 落在 vector_score 域——与 Qdrant
+            # score_threshold（min_vector_score=0.45）同域同语义。
+            ranked = sorted(clustered_input, key=lambda x: -x.vector_score)
+            for item in ranked:
+                item.final_score = item.vector_score
+            rerank_audit = [{"status": "disabled_retrieval_only"}]
         else:
             ranked = sorted(clustered_input, key=lambda x: -(x.rrf_score or x.vector_score))
             for item in ranked:
@@ -1575,6 +1597,8 @@ class QAV1Pipeline:
             ranked,
             top_k_for_llm=top_k_for_llm,
             graph_min_evidence=graph_min_evidence,
+            # 回改 v2：search 预筛用向量域 0.45；chat 走 final 域 0.25
+            min_score=(min_vector_score() if retrieval_only else None),
         )
         assign_evidence_ids(selected)
         timings["cluster_bge_rerank_and_select"] = time.perf_counter() - t0
@@ -3317,11 +3341,15 @@ class QAV1Pipeline:
         *,
         top_k_for_llm: int,
         graph_min_evidence: int,
+        min_score: float | None = None,
     ) -> tuple[List[EvidenceItem], Dict[str, Any]]:
-        # 缺陷 #28（2026-09-11）：相关性下限。低于下限的候选不入选；
-        # 全部低于下限 -> 返回空（前端呈现未命中，与 Qdrant
-        # score_threshold 双保险）。阈值见 score_gate.py（env 可覆盖）。
-        _min_score = min_source_score()
+        # 缺陷 #28 回改 v2（2026-09-11）：相关性下限双域。
+        # - min_score 显式传入时用它（search/retrieval-only 传向量域
+        #   min_vector_score()=0.45）；
+        # - 缺省为 final 域 min_source_score()=0.25（chat 模式语义不变）。
+        # 低于下限的候选不入选；全部低于下限 -> 返回空（前端呈现未命中）。
+        _min_score = min_source_score() if min_score is None else min_score
+        _min_score_domain = "vector" if min_score is not None else "final"
         _below_min = len(ranked) - sum(
             1 for item in ranked if item.final_score >= _min_score
         )  # 被下限过滤的候选数（审计用，见 return 处）
@@ -3376,6 +3404,7 @@ class QAV1Pipeline:
             "graph_quota_satisfied": graph_selected >= graph_min_evidence,
             "min_source_score": _min_score,
             "below_min_source_score": _below_min,
+            "min_score_domain": _min_score_domain,
             "note": "Graph quota is enforced after BGE rerank. If fewer graph candidates exist, all available graph candidates are retained and the deficit is reported.",
         }
 

agent/qa/src/rag/qa_v1_1_73/score_gate.py

@@ -1,23 +1,20 @@
-"""score_gate.py —— 检索相关性下限（缺陷 #28，2026-09-11）。
+"""score_gate.py —— 检索相关性下限（缺陷 #28 回改 v2，2026-09-11）。
 
-语义：候选证据的最终得分（EvidenceItem.final_score）低于下限即视为
-「与问题无关」，不得进入 evidence_top30 / sources。
+双域双常量（TL 2026-09-11 在 175 裸进程 Qdrant 27433 + Ollama bge-m3:567m 实测）：
+- 垃圾问题「景甜是谁」top10 vector_score(cosine) 全部 0.32-0.34；
+- arginine 正常问题 top10 vector_score 0.63+；
+- 垃圾 final_score（BGE rerank 后）仍为 0.19-0.20（测试 agent 实测）。
 
-证据与阈值依据（2026-09-11 实测）：
-- 无关问题「景甜是谁」实测 30 条 final_score 全部 0.19-0.20（纯植物学
-  无关文献）；正常命中（DISCOVERY.md §4.1 金标样本）vector_score=0.714、
-  rerank_score=0.989、final_score=0.982。
-- BGE rerank 路径 final_score = 0.8*bge(sigmoid) + 0.2*rrf/max_rrf；
-  bge 是 sigmoid 概率，0.20 垃圾分对应 raw logit ≈ -1.4，0.25 对应 -1.1，
-  0.30 对应 -0.85，正常命中的 sigmoid 通常 >0.9。
-- Qdrant collection distance=Cosine（score ∈ [-1,1]；bge-m3 文本嵌入对
-  随机中文问题的 top-k 得分通常 <0.2）。
+MIN_VECTOR_SCORE = 0.45（env QA_MIN_VECTOR_SCORE）
+- 语义：向量域（Qdrant Cosine 分数）相关性下限。0.45 位于垃圾带
+  （0.32-0.34）与正常带（0.63+）之间并各留余量。
+- 用途：仅 search / retrieval-only 路径——Qdrant score_threshold 与
+  检索模式预筛。chat 模式不使用（保召回，rerank 后用 MIN_SOURCE_SCORE 兜底）。
 
-默认 0.25：与垃圾实测带（0.19-0.20）留 ~25% 余量，又显著低于正常命中
-（>0.7），同时为 0.2~0.3 边缘问题保留再排序机会（阈值过滤器只是预筛，
-被过滤者已低于下限，保留也无意义）。
-env `QA_MIN_SOURCE_SCORE` 可覆盖（0-1，非法值回落默认），供复测按
-acceptance-r4 §8.3 授权临时调参。
+MIN_SOURCE_SCORE = 0.25（env QA_MIN_SOURCE_SCORE）
+- 语义：最终域（final_score = 0.8*sigmoid(bge) + 0.2*rrf/max_rrf）相关性
+  下限。垃圾 final 0.19-0.20 与其留 ~25% 余量，正常命中 final >0.7。
+- 用途：chat 模式 _select_graph_balanced 的后置过滤（r4-28 语义不变）。
 
 本模块无第三方依赖、无 IO，可被 v16_retriever / direct_flow_retriever /
 pipeline 直接 import（编译期与运行期均安全）。
@@ -26,28 +23,35 @@ from __future__ import annotations
 
 import os
 
-# 相关性下限（与 Qdrant score_threshold 同源同值，双保险）
+DEFAULT_MIN_VECTOR_SCORE = 0.45
 DEFAULT_MIN_SOURCE_SCORE = 0.25
-_ENV_KEY = "QA_MIN_SOURCE_SCORE"
+_ENV_VECTOR = "QA_MIN_VECTOR_SCORE"
+_ENV_SOURCE = "QA_MIN_SOURCE_SCORE"
 
 
-def _env_override() -> float:
-    """env 覆盖：QA_MIN_SOURCE_SCORE ∈ [0,1] 才生效，否则回落默认。"""
-    raw = os.environ.get(_ENV_KEY, "").strip()
+def _env_value(env_key: str, default: float) -> float:
+    """env 覆盖：值 ∈ [0,1] 才生效，否则回落默认。"""
+    raw = os.environ.get(env_key, "").strip()
     if not raw:
-        return DEFAULT_MIN_SOURCE_SCORE
+        return default
     try:
         value = float(raw)
     except ValueError:
-        return DEFAULT_MIN_SOURCE_SCORE
+        return default
     if not (0.0 <= value <= 1.0):
-        return DEFAULT_MIN_SOURCE_SCORE
+        return default
     return value
 
 
+def min_vector_score() -> float:
+    """向量域下限（Qdrant score_threshold / search 预筛）。"""
+    return min_vector_score.value
+
+
 def min_source_score() -> float:
-    """当前生效的相关性下限（模块导入期缓存 env 值，与部署环境一致）。"""
+    """最终域下限（chat 模式 final_score 后置过滤）。"""
     return min_source_score.value
 
 
-min_source_score.value = _env_override()  # type: ignore[attr-defined]
+min_vector_score.value = _env_value(_ENV_VECTOR, DEFAULT_MIN_VECTOR_SCORE)  # type: ignore[attr-defined]
+min_source_score.value = _env_value(_ENV_SOURCE, DEFAULT_MIN_SOURCE_SCORE)  # type: ignore[attr-defined]

agent/qa/src/rag/qa_v1_1_73/test_score_gate.py

@@ -1,16 +1,15 @@
-"""test_score_gate.py —— 相关性下限选择单测（缺陷 #28，acceptance-r4 §2.4）。
+"""test_score_gate.py —— 相关性下限单测（缺陷 #28 回改 v2，2026-09-11）。
 
 运行（venv 内，源码树）：
     cd agent/qa/src/rag/qa_v1_1_73
     python -m pytest test_score_gate.py -v
-（编译期 compile_qa.sh 会把全部 test_*.py 一并编进 .so 树，部署时不冲突；
-正式单测都在源码树跑。）
 
 覆盖：
-- 30 条全部低于下限 -> 选入 0（acceptance 桩）
-- 5 高 + 25 低 -> 仅选入 5（遵循现有配额逻辑）
-- graph 配额不受影响；低于下限的 graph 候选不入选
-- env 覆盖 QA_MIN_SOURCE_SCORE 生效与非法值回落
+- search（retrieval_only）模式：无 LLM 调用、无 rerank 调用；
+  vector 域 0.45 预筛滤掉 0.32 垃圾、保留 0.63 正常；
+  sources 的 score 字段取 vector_score（final_score=vector_score 域）。
+- chat 模式：final 域 0.25 后置过滤语义不变（5 高+25 低 -> 5、30 低 -> 0）；
+  Qdrant score_threshold 不传（None，保召回）。
 """
 from __future__ import annotations
 
@@ -25,7 +24,9 @@ from rag.qa_v1_1_73.schemas import EvidenceItem  # noqa: E402
 from rag.qa_v1_1_73.pipeline import QAV1Pipeline  # noqa: E402
 
 
-def _item(idx: int, *, final: float, graph: bool = False, key: str = "") -> EvidenceItem:
+def _item(
+    idx: int, *, final: float = 0.0, vector: float = 0.0, graph: bool = False, key: str = ""
+) -> EvidenceItem:
     return EvidenceItem(
         evidence_id=f"E{idx}",
         kb="V16",
@@ -35,6 +36,7 @@ def _item(idx: int, *, final: float, graph: bool = False, key: str = "") -> Evid
         evidence=f"evidence body {idx}",
         relation_id=(key or f"rid-{idx}"),
         retrieval_methods=(["neo4j_bounded_expand"] if graph else ["qdrant_vector"]),
+        vector_score=vector,
         final_score=final,
     )
 
@@ -46,30 +48,31 @@ def _select(items, *, top_k=30, graph_min=0):
     return selected, audit
 
 
-def test_all_below_threshold_selects_zero():
-    """acceptance §2.4：30 条全部低于下限 -> 选入 0。"""
+# ---------------------------------------------------------------------------
+# chat 模式 final 域 0.25（r4-28 语义不变）
+# ---------------------------------------------------------------------------
+
+def test_chat_all_below_source_threshold_selects_zero():
+    """30 条 final 全部低于 0.25 -> 选入 0。"""
     items = [_item(i, final=0.20) for i in range(30)]
     selected, audit = _select(items)
     assert selected == []
-    assert audit["policy"].startswith("graph_balanced_top30")
     assert audit["below_min_source_score"] == 30
     assert audit["min_source_score"] == score_gate.min_source_score()
 
 
-def test_five_high_twentyfive_low_selects_only_five():
-    """acceptance §2.4：5 高 + 25 低 -> 仅选入 5（沿用现有配额与 rerank 序）。"""
+def test_chat_five_high_twentyfive_low_selects_only_five():
+    """5 高（final>=0.25）+ 25 低 -> 仅选入 5（保 rerank 序）。"""
     items = [_item(i, final=0.90 - i * 0.01) for i in range(5)]
     items += [_item(5 + i, final=0.20) for i in range(25)]
     selected, audit = _select(items)
     assert len(selected) == 5
-    assert {item.evidence_id for item in selected} == {f"E{i}" for i in range(5)}
-    # 顺序保持 rerank 序
     assert [item.evidence_id for item in selected] == [f"E{i}" for i in range(5)]
     assert audit["below_min_source_score"] == 25
 
 
-def test_below_threshold_graph_candidates_excluded():
-    """低分 graph 候选不占用 graph 配额（配额逻辑语义不变）。"""
+def test_chat_below_threshold_graph_candidates_excluded():
+    """低分 graph 候选不占用 graph 配额。"""
     items = [
         _item(1, final=0.30, graph=True),
         _item(2, final=0.21, graph=True),
@@ -82,17 +85,151 @@ def test_below_threshold_graph_candidates_excluded():
     assert audit["below_min_source_score"] == 2
 
 
-def test_env_override_and_invalid_fallback(monkeypatch):
-    """env 解析函数行为：合法值生效；非法值/越界回落默认。"""
-    monkeypatch.setenv("QA_MIN_SOURCE_SCORE", "0.35")
-    assert score_gate._env_override() == 0.35
-    monkeypatch.setenv("QA_MIN_SOURCE_SCORE", "abc")
-    assert score_gate._env_override() == score_gate.DEFAULT_MIN_SOURCE_SCORE
+# ---------------------------------------------------------------------------
+# search / retrieval-only 模式：免 LLM、免 rerank、vector 域 0.45 预筛
+# ---------------------------------------------------------------------------
+
+class _StubLLM:
+    available = True  # 可用也必须不调用（回改核心断言）
+
+    def complete_json(self, *args, **kwargs):
+        raise AssertionError("search 模式不得调用 LLM")
+
+    def complete(self, *args, **kwargs):
+        raise AssertionError("search 模式不得调用 LLM")
+
+
+class _StubDirectRetriever:
+    """捕获 retrieve 入参，供断言 Qdrant score_threshold 传递。"""
+
+    def __init__(self, items):
+        self.items = items
+        self.last_kwargs = {}
+
+    def retrieve(self, question, queries, hypothesis, **kwargs):
+        self.last_kwargs = kwargs
+        return list(self.items), {
+            "qdrant": [],
+            "seed_extraction": {},
+            "neo4j": [],
+            "dedup": {"qdrant_items": len(self.items)},
+            "options": dict(kwargs),
+        }
+
+    def close(self):
+        pass
+
+
+def _make_pipeline(graph_schema):
+    from rag.qa_v1_1_73.config import QAConfig
+
+    cfg = QAConfig.from_env()
+    if graph_schema == "legacy":
+        object.__setattr__(cfg, "graph_schema", "legacy")
+    import threading
+
+    p = QAV1Pipeline.__new__(QAV1Pipeline)
+    p.config = cfg
+    p._reranker_lock = threading.Lock()
+    p.llm = _StubLLM()
+    p.provisional = _RaisingComposer("provisional")
+    p.hypothesis_extractor = _RaisingComposer("hypothesis")
+    p.query_builder = _StubQueryBuilder()
+    p.reranker = _StubReranker()
+    p.agentic_controller = None
+    p.question_decomposer = None
+    p.subquestion_orchestrator = None
+    p._retriever_stub = _StubDirectRetriever(ITEMS)
+    p.direct_retriever_factory = lambda: p._retriever_stub
+    p.audit = _NullAudit()
+    p.domain = _StubDomain()
+    return p
+
+
+class _RaisingComposer:
+    def __init__(self, name):
+        self.name = name
+
+    def generate(self, *args, **kwargs):
+        raise AssertionError(f"{self.name} 不得被调用")
+
+    def extract(self, *args, **kwargs):
+        raise AssertionError(f"{self.name} 不得被调用")
+
+
+class _StubQueryBuilder:
+    def build(self, question, provisional_answer, hypothesis):
+        return {"hypothesis_lane": [], "direct": [], "concept": []}
+
+
+class _StubReranker:
+    def rerank(self, question, items):
+        raise AssertionError("search 模式不得调用 rerank")
+
+
+class _NullAudit:
+    def new_query_id(self):
+        return "qid"
+
+    def write(self, query_id, payload):
+        return None
+
+
+class _StubDomain:
+    def normalize_hypothesis(self, hypothesis):
+        return {"entities": []}
+
+    def direct_entities_from_question(self, question):
+        return []
+
+
+# 集成（answer()）路径：search 免 rerank，final_score = vector_score（同域），
+# 按 TL 实测向量域构造：垃圾 0.32（< 0.45 滤掉）、正常 0.63（保留）。
+JUNK = _item(1, vector=0.32)
+GOOD = _item(2, vector=0.63)
+ITEMS = [JUNK, GOOD]
+
+
+def test_search_mode_no_llm_no_rerank_keeps_good_only():
+    p = _make_pipeline("legacy")
+    out = p.answer(
+        "景甜是谁",
+        retrieval_only=True,
+        native_chain_enabled=False,
+        progress_callback=None,
+    )
+    assert out["sources"] != []  # vector 0.63 保留
+    titles = [src["source"] for src in out["sources"]]
+    assert "src2" in titles and "src1" not in titles  # 0.32 垃圾被 0.45 预筛滤掉
+    assert p._retriever_stub.last_kwargs["qdrant_score_threshold"] == 0.45
+    assert out["retrieval_audit"]["options"]["qdrant_score_threshold"] == 0.45
+    assert out["query_plan"]["agentic_plan"]["plan_source"] == "deterministic_retrieval_only_plan"
+    assert out["degraded_execution"] is False
+    # 跳过 rerank 后：final_score = vector_score（TL 回改语义，与 Qdrant 阈值
+    # 同域）；rerank_score 未精排（0.0）。BFF normalize 的 score 取 final_score。
+    for src in out["sources"]:
+        assert src["rerank_score"] == 0.0
+        assert src["final_score"] == src["vector_score"]
+
+
+def test_chat_mode_passes_no_threshold():
+    p = _make_pipeline("legacy")
+    object.__setattr__(p.config, "enable_bge_rerank", False)
+    out = p.answer(
+        "景甜是谁",
+        retrieval_only=False,
+        native_chain_enabled=False,
+        progress_callback=None,
+    )
+    assert p._retriever_stub.last_kwargs["qdrant_score_threshold"] is None
+
+
+def test_env_overrides(monkeypatch):
+    monkeypatch.setenv("QA_MIN_VECTOR_SCORE", "0.5")
+    assert score_gate._env_value("QA_MIN_VECTOR_SCORE", 0.45) == 0.5
+    monkeypatch.setenv("QA_MIN_VECTOR_SCORE", "abc")
+    assert score_gate._env_value("QA_MIN_VECTOR_SCORE", 0.45) == 0.45
     monkeypatch.setenv("QA_MIN_SOURCE_SCORE", "1.5")
-    assert score_gate._env_override() == score_gate.DEFAULT_MIN_SOURCE_SCORE
+    assert score_gate._env_value("QA_MIN_SOURCE_SCORE", 0.25) == 0.25
+    monkeypatch.delenv("QA_MIN_VECTOR_SCORE", raising=False)
     monkeypatch.delenv("QA_MIN_SOURCE_SCORE", raising=False)
-    # 生效值（value 属性）驱动 _select_graph_balanced 的过滤
-    monkeypatch.setattr(score_gate.min_source_score, "value", 0.35)
-    items = [_item(i, final=0.30) for i in range(5)]
-    selected, _ = _select(items)
-    assert selected == []

agent/qa/src/rag/qa_v1_1_73/v16_retriever.py

@@ -9,7 +9,6 @@ from typing import Any, Dict, List
 import requests
 from neo4j import GraphDatabase
 from qdrant_client import QdrantClient
-from .score_gate import min_source_score
 
 
 TOKEN_RE = re.compile(r"[A-Za-z][A-Za-z0-9_.-]{2,}|[\u4e00-\u9fff]{2,}")
@@ -101,15 +100,11 @@ class V16IndependentRetriever:
         self, question: str, limit: int, include_candidate: bool
     ) -> List[Dict[str, Any]]:
         try:
-            # 缺陷 #28（2026-09-11）：相关性下限双保险（与 pipeline
-            # _select_graph_balanced 同源同值）。collection distance=Cosine，
-            # 阈值语义 = 余弦相似度下限；低于下限的点直接不返回。
             response = self.qdrant.query_points(
                 collection_name=self.collection,
                 query=self.embed(question),
                 limit=limit * 2,
                 with_payload=True,
-                score_threshold=min_source_score(),
             )
         except Exception:
             return []