feat: 完善报销单审批流程及退回原因追踪

新增直属领导审批通过接口和审批待办列表查询，报销单退回
支持原因码分类和审批环节标记，优化票据附件去重和路径
回退查找，前端新增退回原因对话框、审批收件箱和工作台
图标组件，补充工具函数和单元测试覆盖。

server/src/app/api/v1/endpoints/reimbursements.py

@@ -12,6 +12,7 @@ from app.schemas.reimbursement import (
     ExpenseClaimAttachmentActionResponse,
     ExpenseClaimActionResponse,
     ExpenseClaimAttachmentRead,
+    ExpenseClaimApprovalPayload,
     ExpenseClaimItemCreate,
     ExpenseClaimItemActionResponse,
     ExpenseClaimItemUpdate,
@@ -59,6 +60,16 @@ def list_expense_claims(db: DbSession, current_user: CurrentUser) -> list[Expens
     return ExpenseClaimService(db).list_claims(current_user)
 
 
+@router.get(
+    "/claims/approvals",
+    response_model=list[ExpenseClaimRead],
+    summary="查询当前用户审批待办报销单列表",
+    description="返回当前登录用户有权处理的待审批报销单据，不混入个人报销列表。",
+)
+def list_expense_claim_approvals(db: DbSession, current_user: CurrentUser) -> list[ExpenseClaimRead]:
+    return ExpenseClaimService(db).list_approval_claims(current_user)
+
+
 @router.get(
     "/claims/{claim_id}",
     response_model=ExpenseClaimRead,
@@ -420,7 +431,7 @@ def submit_expense_claim(claim_id: str, db: DbSession, current_user: CurrentUser
     "/claims/{claim_id}/return",
     response_model=ExpenseClaimRead,
     summary="退回报销单",
-    description="财务人员或高级管理人员可将可见报销单退回到待提交状态。",
+    description="财务人员、高级管理人员或当前审批人可将可见报销单退回到待提交状态。",
     responses={
         status.HTTP_404_NOT_FOUND: {
             "model": ErrorResponse,
@@ -440,7 +451,40 @@ def return_expense_claim(
 ) -> ExpenseClaimRead:
     service = ExpenseClaimService(db)
     try:
-        claim = service.return_claim(claim_id, current_user, reason=payload.reason)
+        claim = service.return_claim(claim_id, current_user, reason=payload.reason, reason_codes=payload.reason_codes)
+    except ValueError as error:
+        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail=str(error)) from error
+
+    if claim is None:
+        raise HTTPException(status_code=status.HTTP_404_NOT_FOUND, detail="Claim not found")
+    return claim
+
+
+@router.post(
+    "/claims/{claim_id}/approve",
+    response_model=ExpenseClaimRead,
+    summary="直属领导审批通过报销单",
+    description="当前审批人确认报销信息无误后，将报销单从直属领导审批流转到财务审批。",
+    responses={
+        status.HTTP_404_NOT_FOUND: {
+            "model": ErrorResponse,
+            "description": "报销单不存在。",
+        },
+        status.HTTP_400_BAD_REQUEST: {
+            "model": ErrorResponse,
+            "description": "当前用户或单据状态不允许审批通过。",
+        },
+    },
+)
+def approve_expense_claim(
+    claim_id: str,
+    payload: ExpenseClaimApprovalPayload,
+    db: DbSession,
+    current_user: CurrentUser,
+) -> ExpenseClaimRead:
+    service = ExpenseClaimService(db)
+    try:
+        claim = service.approve_claim(claim_id, current_user, opinion=payload.opinion)
     except ValueError as error:
         raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail=str(error)) from error