test: CMA自动化测试补覆盖 226→452用例, 覆盖率36%→60%

- 新增8个测试文件(bot_bridge/kpi_causality/cash/predict/reports/tax_compliance/expenses/probe_cost)
- 增强 budget/auth/users + conftest账套模式适配
- 测试驱动修复: bot_bridge导入batch_id→source_batch; cash_forecast extra空dict
- 全量: 451 passed, 1 xfailed; 报告 docs/cma-test-coverage-report.md

backend/app/api/bot_bridge.py

@@ -529,7 +529,7 @@ def bot_import_excel(
                 continue
             
             kv = KPIValue(kpi_id=kpi.id, period=period, actual_value=val,
-                          batch_id=hashlib.md5(f"{datetime.now()}".encode()).hexdigest()[:12])
+                          source_batch=hashlib.md5(f"{datetime.now()}".encode()).hexdigest()[:12])
             db.add(kv)
             count += 1
         except Exception as e:

backend/app/utils/cash_forecast_engine.py

@@ -320,6 +320,7 @@ def calculate_accuracy(entity_id: int, db: Session) -> list:
 
 def generate_scenario_suggestion(alert_type: str, kpi_name: str, extra: dict = None) -> dict:
     """根据预警类型生成情景建议"""
+    extra = extra or {}
     suggestions = {
         "cash_low": {
             "title": "现金流紧张缓解方案",
@@ -624,7 +625,7 @@ def forecast_cash_flow_with_plans(
 def check_cash_alerts(db: Session, entity_id: int = 1) -> dict:
     """资金预警 — 缺口前3天预警 + 到期未收款提醒，写入预警中心(kpi_alerts)"""
     import json as _json
-    from app.models import KPIAlert, CashPlan
+    from app.models import KPIAlert, CashPlan, KPIDefinition
 
     result = forecast_cash_flow_with_plans(entity_id, db, days=30)
     new_alerts = []