feat: 新增预算费控模型与报销审批流引擎

后端新增预算费控服务和报销单审批流模块，引入申请人费用画像
算法，优化知识库 RAG 运行时和同步逻辑，完善报销单工作流常
量和明细同步，更新差旅报销规则电子表格，前端新增预算分析
组件和数字员工模型，完善审批对话框和洞察面板交互，优化侧
边栏和顶栏样式，补充单元测试。

server/src/app/services/budget.py

@@ -20,6 +20,7 @@ from app.schemas.budget import (
     BudgetSummaryRead,
     BudgetTransactionRead,
 )
+from app.services.budget_expense_control import BudgetExpenseControlModel
 from app.services.budget_support import BudgetSupportMixin
 from app.services.budget_types import BudgetControlError, SUPPORTED_BUDGET_SUBJECT_CODES
 
@@ -112,6 +113,9 @@ class BudgetService(BudgetSupportMixin):
             warnings=warnings,
         )
 
+    def analyze_claim_budget(self, claim: ExpenseClaim) -> dict[str, Any]:
+        return BudgetExpenseControlModel().assess(self.build_claim_budget_context(claim), claim)
+
     def create_or_update_allocation(
         self,
         payload: BudgetAllocationCreate,