feat: 多租户隔离P2批2 — 预算/成本/费用/预警规则/BI报表加entity_id

- 12表加entity_id列(预算/偏差/规则/成本4表/费用2表/BI2表/驱动预算)
- 模型: BudgetPlan/StandardCost/ActualCost/AbcActivity/AbcAllocation/DriverFactorBudget/BiReport/Template/BudgetDeviationAlert/ExpenseRule/Reimbursement/AlertRule
- API隔离: budget plans / cost standard+actual / expenses rules+reimb / bi_reports list / alert_rules list 按token企业过滤
- 回填: kpi_id关联按KPI归属, 无关联默认酣客(entity=1); 当前数据全归酣客
- 验证: import+全端点200+pytest 451 passed

backend/app/models/__init__.py

@@ -333,6 +333,7 @@ class BiReportTemplate(Base):
     """BI报表模板"""
     __tablename__ = "bi_report_templates"
     id = Column(Integer, primary_key=True, index=True)
+    entity_id = Column(Integer, default=1, comment="企业ID (P2多租户隔离 2026-08-23)")
     name = Column(String(200), nullable=False, comment="模板名称")
     report_type = Column(String(50), nullable=False, comment="overview/trend/comparison/topn/causality")
     config = Column(JSON, nullable=False, comment="报表配置")
@@ -346,6 +347,7 @@ class BiReport(Base):
     """用户保存的BI报表"""
     __tablename__ = "bi_reports"
     id = Column(Integer, primary_key=True, index=True)
+    entity_id = Column(Integer, default=1, comment="企业ID (P2多租户隔离 2026-08-23)")
     template_id = Column(Integer, ForeignKey("bi_report_templates.id"), nullable=True)
     name = Column(String(200), nullable=False, comment="报表名称")
     config = Column(JSON, nullable=False, comment="报表配置（行/列/值）")
@@ -466,6 +468,7 @@ class BudgetDeviationAlert(Base):
     """预算偏差预警记录"""
     __tablename__ = "budget_deviation_alerts"
     id = Column(Integer, primary_key=True, index=True)
+    entity_id = Column(Integer, default=1, comment="企业ID (P2多租户隔离 2026-08-23)")
     kpi_id = Column(Integer, ForeignKey("kpi_definitions.id"), nullable=False, comment="关联KPI")
     period = Column(String(20), nullable=False, comment="期间 YYYY-MM")
     budget_value = Column(Float, nullable=True, comment="预算值")
@@ -583,6 +586,7 @@ class ExpenseRule(Base):
     """费用规则 — 自动校验报销单的标准"""
     __tablename__ = "expense_rules"
     id = Column(Integer, primary_key=True, index=True)
+    entity_id = Column(Integer, default=1, comment="企业ID (P2多租户隔离 2026-08-23)")
     rule_name = Column(String(100), nullable=False, comment="规则名称")
     dimension = Column(String(20), nullable=False, comment="维度: department/person/expense_type")
     dimension_value = Column(String(100), nullable=True, comment="维度值: 部门名/人员名/费用类型(空=全局)")
@@ -600,6 +604,7 @@ class ExpenseReimbursement(Base):
     """费用报销单 — 提交后自动校验规则，超限自动打回"""
     __tablename__ = "expense_reimbursements"
     id = Column(Integer, primary_key=True, index=True)
+    entity_id = Column(Integer, default=1, comment="企业ID (P2多租户隔离 2026-08-23)")
     reimb_no = Column(String(50), unique=True, nullable=False, comment="报销单号")
     applicant = Column(String(100), nullable=False, comment="申请人")
     department = Column(String(100), nullable=True, comment="部门")