feat: 新增客服备用金台账与后台用户中文显示名

- 新增备用金账户、流水、支出、对账与权限
- 后台用户支持中文显示名并同步备用金姓名
- 审计、登录记录、任务及工单操作人优先展示中文名
- 补充备用金与人工支出方案文档

apps/frontend/src/layouts/AdminLayout.tsx

@@ -17,6 +17,7 @@ import {
   TrophyOutlined,
   UnorderedListOutlined,
   UserOutlined,
+  WalletOutlined,
 } from '@ant-design/icons'
 import {
   App,
@@ -45,10 +46,12 @@ import {
 } from '@/services/admin'
 import {
   clearAdminSession,
+  getAdminDisplayName,
   getAdminRole,
   getAdminToken,
   getAdminTokenExpiresAt,
   getAdminUsername,
+  setAdminDisplayName,
   setAdminPermissions,
 } from '@/utils/admin-auth'
 import { formatAdminDateTime } from '@/utils/admin-time'
@@ -89,9 +92,13 @@ export default function AdminLayout() {
     const session = adminSessionQuery.data?.data
     if (session?.authenticated && session.user) {
       setAdminPermissions(session.user.permissions || [])
+      setAdminDisplayName(session.user.displayName || session.user.username)
     }
   }, [adminSessionQuery.data])
 
+  const displayName =
+    adminSessionQuery.data?.data.user?.displayName || getAdminDisplayName() || username
+
   const devMockStatusQuery = useQuery({
     queryKey: ['admin-dev-mock-status'],
     queryFn: () => fetchDevMockStatus(),
@@ -124,11 +131,17 @@ export default function AdminLayout() {
       role === 'finance'
         ? [
             { key: '/admin/finance', icon: <AccountBookOutlined />, label: '财务' },
+            { key: '/admin/fund', icon: <WalletOutlined />, label: '备用金' },
             { key: '/admin/worker-platform', icon: <TrophyOutlined />, label: '资金审核' },
           ]
         : [
             { key: '/admin/dashboard', icon: <DashboardOutlined />, label: '概览' },
             { key: '/admin/orders', icon: <OrderedListOutlined />, label: '订单' },
+            {
+              key: '/admin/fund',
+              icon: <WalletOutlined />,
+              label: role === 'support' ? '我的备用金' : '备用金',
+            },
             ...(role === 'support'
               ? []
               : [{ key: '/admin/finance', icon: <AccountBookOutlined />, label: '财务' }]),
@@ -291,7 +304,10 @@ export default function AdminLayout() {
 
           {!collapsed ? (
             <div className="admin-sidebar-profile">
-              <Typography.Text strong>{username}</Typography.Text>
+              <Typography.Text strong>{displayName}</Typography.Text>
+              {displayName !== username ? (
+                <Typography.Text type="secondary">@{username}</Typography.Text>
+              ) : null}
               <Typography.Text type="secondary">{roleLabel(role)}</Typography.Text>
               {expiresAt ? (
                 <Typography.Text type="secondary">