feat(ui): 引入 sonner 消息反馈系统，并在首页部署全局行情同步按钮

app/dashboard/page.tsx

@@ -2,6 +2,7 @@ import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
 import { getPortfolioSummary } from '@/actions/portfolio';
 import { formatQuantity, formatAmount } from '@/lib/formatters';
 import AllocationChart from '@/components/dashboard/allocation-chart';
+import { SyncButton } from '@/components/assets/sync-button';
 import Big from 'big.js';
 
 const CHART_COLORS = [
@@ -33,6 +34,10 @@ export default async function DashboardPage() {
       </div>
 
       <Card>
+        <CardHeader className="flex flex-row items-center justify-between space-y-0 pb-2">
+          <CardTitle className="text-sm font-medium">总资产概览</CardTitle>
+          <SyncButton />
+        </CardHeader>
         <CardContent className="pt-6 pb-6">
           <div className="flex items-center gap-3">
             <span className="text-2xl font-semibold text-muted-foreground">