✨ feat(expenses): 优化费用金额输入体验

- 替换Input为InputNumber组件，提供更精确的数字输入控制
- 添加金额最小值限制为0.01元
- 设置数字精度为2位小数，确保金额格式规范
- 添加步长控制为0.01，方便微调金额数值

src/client/admin/pages/Expenses.tsx

@@ -1,4 +1,5 @@
 import React, { useState, useEffect } from 'react';
+import { InputNumber } from 'antd';
 import { Table, Button, Space, Input, Modal, Form, Select, DatePicker, Card, Typography, Layout, Spin, Tag } from 'antd';
 import { App } from 'antd';
 import { PlusOutlined, EditOutlined, DeleteOutlined, SearchOutlined, FilterOutlined, DownloadOutlined, ReloadOutlined } from '@ant-design/icons';
@@ -629,12 +630,12 @@ const Expenses: React.FC = () => {
               label="费用金额"
               rules={[
                 { required: true, message: '请输入费用金额' },
-                { type: 'number', message: '金额必须是数字' },
-                { min: 0.01, message: '金额必须大于0' }
               ]}
             >
-              <Input 
-                type="number" 
+              <InputNumber 
+                min={0.01}
+                precision={2}
+                step={0.01}
                 placeholder="请输入费用金额" 
                 style={{ width: '100%' }}
               />