feat: 增强风险规则生成引擎与预算中心页面

后端拆分风险规则生成为解释器、语义分析、本体对齐等子模块，
优化模板执行和流程图生成，完善员工种子数据和导入逻辑，增强
报销单权限策略和草稿持久化，前端新增预算中心视图和趋势图
组件，重构审计页面和风险规则测试对话框交互，完善文档中心
和报销创建页面细节，补充单元测试覆盖。

server/src/app/services/expense_claim_draft_persistence.py

@@ -33,6 +33,7 @@ from app.services.agent_asset_spreadsheet import RISK_RULES_LIBRARY
 from app.services.agent_foundation import AgentFoundationService
 from app.services.audit import AuditLogService
 from app.services.document_intelligence import build_document_insight
+from app.services.document_numbering import generate_unique_expense_claim_no
 from app.services.expense_claim_access_policy import ExpenseClaimAccessPolicy
 from app.services.expense_claim_attachment_presentation import ExpenseClaimAttachmentPresentation
 from app.services.expense_claim_attachment_storage import ExpenseClaimAttachmentStorage
@@ -250,23 +251,11 @@ class ExpenseClaimDraftPersistenceMixin:
         )
 
     def _generate_claim_no(self, occurred_at: datetime) -> str:
-        month_code = occurred_at.strftime("%Y%m")
-        prefix = f"EXP-{month_code}-"
-        existing_claim_nos = list(
-            self.db.scalars(
-                select(ExpenseClaim.claim_no).where(ExpenseClaim.claim_no.like(f"{prefix}%"))
-            )
+        return generate_unique_expense_claim_no(
+            self.db,
+            "reimbursement",
+            timestamp=datetime.now(UTC),
         )
-        max_suffix = 0
-        for claim_no in existing_claim_nos:
-            normalized = str(claim_no or "").strip()
-            if not normalized.startswith(prefix):
-                continue
-            suffix = normalized[len(prefix):]
-            if not suffix.isdigit():
-                continue
-            max_suffix = max(max_suffix, int(suffix))
-        return f"{prefix}{max_suffix + 1:03d}"
 
     @staticmethod
     def _resolve_claim_no_retry_count(context_json: dict[str, Any]) -> int: