refactor: 提取 buildNavUrl 工具函数，统一 room API 错误处理

- 将 MatchResult.tsx 和 profile/page.tsx 中重复的导航 URL 构建逻辑提取到 src/lib/navigation.ts
- 7 个 room API 路由从 return NextResponse.json({ error }, { status }) 统一改为 throw ApiError，由 apiHandler 统一捕获

src/lib/navigation.ts

@@ -0,0 +1,9 @@
+import type { Restaurant } from "@/types";
+
+export function buildNavUrl(restaurant: Restaurant): string {
+  if (restaurant.location) {
+    const [lng, lat] = restaurant.location.split(",");
+    return `https://uri.amap.com/marker?position=${lng},${lat}&name=${encodeURIComponent(restaurant.name)}&callnative=1`;
+  }
+  return `https://www.google.com/maps/search/?api=1&query=${encodeURIComponent(restaurant.name)}`;
+}