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/test_config_scenarios.py

@@ -0,0 +1,100 @@
+"""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 == []