feat(dashboard): 构建基于 Big.js 的持仓聚合引擎与总览卡片

app/dashboard/page.tsx

@@ -1,14 +1,53 @@
 import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
+import { getPortfolioPositions } from '@/actions/portfolio';
+import { formatQuantity } from '@/lib/formatters';
+
+export default async function DashboardPage() {
+  const positions = await getPortfolioPositions();
 
-export default function DashboardPage() {
   return (
-    <Card className="max-w-md">
-      <CardHeader>
-        <CardTitle>欢迎来到 Omniledger</CardTitle>
-      </CardHeader>
-      <CardContent>
+    <div className="space-y-6">
+      <div>
+        <h1 className="text-3xl font-bold">欢迎来到 Omniledger</h1>
         <p className="text-muted-foreground">您的跨界记账中枢。</p>
-      </CardContent>
-    </Card>
+      </div>
+
+      <div className="grid grid-cols-1 md:grid-cols-3 gap-4">
+        {positions.length === 0 ? (
+          <Card>
+            <CardContent className="pt-6">
+              <p className="text-muted-foreground">暂无持仓，请先添加资产和交易记录。</p>
+            </CardContent>
+          </Card>
+        ) : (
+          positions.map((pos) => (
+            <Card key={pos.assetId}>
+              <CardHeader>
+                <CardTitle className="flex items-center justify-between">
+                  <span>{pos.symbol}</span>
+                  <span className="text-sm font-normal text-muted-foreground">
+                    {pos.type}
+                  </span>
+                </CardTitle>
+              </CardHeader>
+              <CardContent>
+                <div className="space-y-2">
+                  <div className="flex justify-between">
+                    <span className="text-muted-foreground">持仓数量</span>
+                    <span className="font-medium">
+                      {formatQuantity(pos.quantity, pos.type)}
+                    </span>
+                  </div>
+                  <div className="flex justify-between">
+                    <span className="text-muted-foreground">结算币种</span>
+                    <span className="font-medium">{pos.baseCurrency}</span>
+                  </div>
+                </div>
+              </CardContent>
+            </Card>
+          ))
+        )}
+      </div>
+    </div>
   );
-}
+}