feat: 添加可配置场景注册表与规则引擎

- 新增场景基类、配置加载、注册表与原语模块
- 添加 r10_refund_split 规则及场景 JSON Schema
- 扩展 scan 引擎与 scenarios API
- 新增场景注册表/配置/集成测试
- 更新前端 App、api、labels 支持新场景

backend/tests/integration/test_run_scenarios.py

@@ -0,0 +1,62 @@
+"""通用场景调度器 run_scenarios 的落库集成测试（需 PostgreSQL）。
+
+验证「场景插件 → 统一调度 → 阈值过滤 → 落库」链路，且与旧 run_xxx_scan 行为一致。
+"""
+
+from __future__ import annotations
+
+from app.clues.models import ClueStatus, ConfidenceTier
+from app.engines import scan
+from app.scenarios.churn_fraud import ChurnFraudScenario, CohortPoint
+from app.scenarios.split_contract import ContractRecord, SplitContractScenario
+
+
+def test_run_scenarios_creates_clues(session):
+    contracts = [ContractRecord(f"C{i}", f"CUST{i}", 850000) for i in range(8)]
+    curve = [CohortPoint(0, 1.0), CohortPoint(1, 0.95), CohortPoint(2, 0.1)]
+    scenarios = [
+        SplitContractScenario(
+            contracts, approval_threshold=1_000_000, shared_controller=True
+        ),
+        ChurnFraudScenario(
+            retention_curve=curve,
+            commission_paid=300000,
+            active_ratio=0.05,
+            zero_usage_ratio=0.9,
+            channel_key="CH-001",
+        ),
+    ]
+    results = scan.run_scenarios(session, scenarios)
+    by_code = {r.scenario_code: r for r in results}
+
+    assert by_code["R8"].scanned_count == 8
+    assert len(by_code["R8"].clues) == 1
+    r8_clue = by_code["R8"].clues[0]
+    assert r8_clue.confidence == ConfidenceTier.HIGH
+    assert r8_clue.status == ClueStatus.NEW
+    assert r8_clue.amount_involved > 0
+    assert r8_clue.model_version == scan.MODEL_VERSION
+
+    assert by_code["R9"].scanned_count == 3
+    assert len(by_code["R9"].clues) == 1
+    assert by_code["R9"].clues[0].scenario_code == "R9"
+    assert by_code["R9"].clues[0].subjects["channel"] == "CH-001"
+
+
+def test_run_scenarios_filters_below_threshold(session):
+    # 干净数据：拆单不命中、养卡曲线平滑且佣金匹配 → 均不应生成线索
+    contracts = [ContractRecord("C1", "A", 100000), ContractRecord("C2", "B", 3_000_000)]
+    curve = [CohortPoint(0, 1.0), CohortPoint(1, 0.98), CohortPoint(2, 0.97)]
+    scenarios = [
+        SplitContractScenario(contracts, approval_threshold=1_000_000),
+        ChurnFraudScenario(
+            retention_curve=curve,
+            commission_paid=10000,
+            active_ratio=0.9,
+            zero_usage_ratio=0.05,
+            channel_key="CH-X",
+        ),
+    ]
+    results = scan.run_scenarios(session, scenarios)
+    for r in results:
+        assert r.clues == []

backend/tests/test_config_scenarios.py

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+"""配置驱动场景（B 快捷通道）测试：原语库、YAML 加载与校验、ConfigScenario 扫描。
+
+纯逻辑，无需数据库。验证「新增 YAML → 自动注册 → 可扫描产出线索草稿」链路。
+"""
+
+from __future__ import annotations
+
+import pytest
+from pydantic import ValidationError
+
+from app.scenarios.config import (
+    ScenarioConfig,
+    load_yaml_scenarios,
+)
+from app.scenarios.primitives import cliff_drop, ratio_threshold, threshold_edge
+from app.scenarios.registry import SCENARIO_REGISTRY, get_scenario
+
+
+# ---------- 原语库 ----------
+
+def test_threshold_edge_primitive_hits():
+    rows = [{"refund_amount": 450000, "customer": f"C{i}"} for i in range(5)]
+    res = threshold_edge(
+        rows,
+        {"amount_field": "refund_amount", "threshold": 500000, "key_field": "customer"},
+    )
+    assert res.hit
+    assert res.score > 0
+    assert res.evidence["near_count"] == 5
+    assert len(res.subjects["keys"]) == 5
+
+
+def test_threshold_edge_primitive_no_hit_when_spread():
+    rows = [{"refund_amount": 100000}, {"refund_amount": 900000}]
+    res = threshold_edge(rows, {"amount_field": "refund_amount", "threshold": 500000})
+    assert not res.hit
+    assert res.score == 0.0
+
+
+def test_threshold_edge_requires_positive_threshold():
+    with pytest.raises(ValueError):
+        threshold_edge([], {"amount_field": "x", "threshold": 0})
+
+
+def test_cliff_drop_primitive():
+    rows = [{"m": 0, "v": 1.0}, {"m": 1, "v": 0.95}, {"m": 2, "v": 0.1}]
+    res = cliff_drop(rows, {"index_field": "m", "value_field": "v"})
+    assert res.hit
+    assert res.evidence["cliff_at"] == 2
+
+
+def test_ratio_threshold_primitive():
+    rows = [{"z": 0.9}, {"z": 0.95}]
+    res = ratio_threshold(
+        rows, {"value_field": "z", "agg": "mean", "op": ">=", "threshold": 0.8}
+    )
+    assert res.hit
+    assert res.score == 0.8
+
+
+# ---------- YAML 配置校验 ----------
+
+def test_scenario_config_validation_error():
+    with pytest.raises(ValidationError):
+        ScenarioConfig(code="R99")  # 缺 title/risk_domain/label/detector
+
+
+def test_load_yaml_scenarios_registers_r10():
+    load_yaml_scenarios()  # 加载内置 rules/*.yaml（含 R10 示例）
+    assert "R10" in SCENARIO_REGISTRY
+    cls = get_scenario("R10")
+    assert cls is not None
+    assert cls.label == "退款拆分"
+    assert cls.risk_domain == "收入"
+
+
+# ---------- ConfigScenario 扫描 ----------
+
+def test_config_scenario_scan_produces_clue_draft():
+    load_yaml_scenarios()
+    cls = get_scenario("R10")
+    rows = [{"refund_amount": 460000 + i * 5000, "customer": f"政企{i}"} for i in range(6)]
+    outcome = cls(rows=rows).scan(None)
+    assert outcome.scanned_count == 6
+    assert len(outcome.drafts) == 1
+    draft = outcome.drafts[0]
+    assert draft.score > 0
+    assert "退款" in draft.rationale  # rationale_template 生效
+    assert "keys" in draft.subjects
+
+
+def test_config_scenario_no_draft_when_clean():
+    load_yaml_scenarios()
+    cls = get_scenario("R10")
+    rows = [
+        {"refund_amount": 100000, "customer": "A"},
+        {"refund_amount": 2_000_000, "customer": "B"},
+    ]
+    outcome = cls(rows=rows).scan(None)
+    assert outcome.drafts == []

backend/tests/test_scenario_registry.py

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+"""场景插件框架测试：注册表、场景 scan() 产出、/scenarios API（纯逻辑，无需数据库）。"""
+
+from __future__ import annotations
+
+from fastapi.testclient import TestClient
+
+from app.main import app
+from app.scenarios.base import ScanOutcome
+from app.scenarios.churn_fraud import ChurnFraudScenario, CohortPoint
+from app.scenarios.registry import SCENARIO_REGISTRY, get_scenario, scenario_meta
+from app.scenarios.split_contract import ContractRecord, SplitContractScenario
+
+
+def test_registry_contains_builtin_scenarios():
+    # 导入 app.scenarios.* 已通过自动发现触发 @register_scenario 注册 R8/R9
+    assert "R8" in SCENARIO_REGISTRY
+    assert "R9" in SCENARIO_REGISTRY
+    assert get_scenario("R8") is SplitContractScenario
+    assert get_scenario("R9") is ChurnFraudScenario
+
+
+def test_scenario_meta_fields():
+    meta = {m["code"]: m for m in scenario_meta()}
+    assert meta["R8"]["label"] == "政企拆单"
+    assert meta["R8"]["risk_domain"] == "收入"
+    assert meta["R9"]["label"] == "养卡骗补"
+    assert set(meta["R8"]) == {"code", "title", "label", "risk_domain"}
+
+
+def test_split_scenario_scan_hits():
+    contracts = [ContractRecord(f"C{i}", f"CUST{i}", 850000) for i in range(8)]
+    scenario = SplitContractScenario(
+        contracts, approval_threshold=1_000_000, shared_controller=True
+    )
+    outcome = scenario.scan(None)
+    assert isinstance(outcome, ScanOutcome)
+    assert outcome.scanned_count == 8
+    assert len(outcome.drafts) == 1
+    draft = outcome.drafts[0]
+    assert draft.score >= scenario.score_threshold
+    assert draft.amount_involved > 0
+    assert draft.evidence["shared_controller"] is True
+
+
+def test_split_scenario_no_draft_when_clean():
+    contracts = [ContractRecord("C1", "A", 100000), ContractRecord("C2", "B", 3_000_000)]
+    outcome = SplitContractScenario(contracts, approval_threshold=1_000_000).scan(None)
+    assert outcome.drafts == []
+    assert outcome.scanned_count == 2
+
+
+def test_churn_scenario_scan_produces_draft():
+    curve = [CohortPoint(0, 1.0), CohortPoint(1, 0.95), CohortPoint(2, 0.1)]
+    scenario = ChurnFraudScenario(
+        retention_curve=curve,
+        commission_paid=300000,
+        active_ratio=0.05,
+        zero_usage_ratio=0.9,
+        channel_key="CH-001",
+    )
+    outcome = scenario.scan(None)
+    assert outcome.scanned_count == 3
+    assert len(outcome.drafts) == 1
+    draft = outcome.drafts[0]
+    assert draft.subjects["channel"] == "CH-001"
+    assert draft.score >= scenario.score_threshold
+
+
+def test_scenarios_api_endpoint():
+    client = TestClient(app)
+    resp = client.get("/scenarios")
+    assert resp.status_code == 200
+    codes = {item["code"] for item in resp.json()}
+    assert {"R8", "R9"} <= codes