feat: deduct personal expenses from deposit refunds

apps/server/src/deposits/deposits.refund.spec.ts

@@ -2,9 +2,10 @@ import { DepositsService } from './deposits.service';
 import { Deposit } from '../entities/deposit.entity';
 
 describe('DepositsService — direct refund', () => {
-  it('refunds the full available balance and stores audit fields', async () => {
+  it('deducts unbilled personal expenses before refunding the remaining balance', async () => {
     const deposit = {
       id: 1,
+      studentId: 10,
       amount: 500,
       status: 'paid',
     } as Deposit;
@@ -12,7 +13,17 @@ describe('DepositsService — direct refund', () => {
       findOne: jest.fn().mockResolvedValue(deposit),
       save: jest.fn().mockImplementation(async (value: Deposit) => value),
     };
-    const service = new DepositsService(repo as never, {} as never, {} as never);
+    const personalExpenseRepo = {
+      createQueryBuilder: jest.fn().mockReturnValue({
+        select: jest.fn().mockReturnThis(),
+        addSelect: jest.fn().mockReturnThis(),
+        where: jest.fn().mockReturnThis(),
+        andWhere: jest.fn().mockReturnThis(),
+        groupBy: jest.fn().mockReturnThis(),
+        getRawMany: jest.fn().mockResolvedValue([{ studentId: 10, amount: '120' }]),
+      }),
+    };
+    const service = new DepositsService(repo as never, {} as never, {} as never, personalExpenseRepo as never);
 
     const result = await service.refund(
       1,
@@ -23,7 +34,9 @@ describe('DepositsService — direct refund', () => {
     expect(result).toMatchObject({
       refundDate: '2026-07-13',
       amount: 0,
-      refundAmount: 500,
+      refundAmount: 380,
+      deductionAmount: 120,
+      deductionReason: '自动扣除个人附加费用 ¥120.00',
       notes: '退还剩余押金',
       status: 'refunded',
       refundedBy: 42,