style(pwa-install-dialog): redesign dialog to match Dart spec

Update the PWA install dialog styling and content to align with the
original Dart design, including a white background with large 40px
radius, 86x86 PNG icon, gradient primary button, and dynamic app title
sourced from AppConstants.

src/lib/auth/nextauth.ts

@@ -33,6 +33,10 @@ const handler = NextAuth({
   pages: {
     signIn: "/auth",
   },
+  // 显式允许从请求头（X-Forwarded-Host）推断 host；消除 v4 [NEXTAUTH_URL] 警告
+  // 生产部署在反向代理后（nginx / cloudflare）必须开
+  // @ts-expect-error: `trustHost` 不在 v4.24.x 的 AuthOptions 类型里，但运行时支持
+  trustHost: true,
   secret: process.env.AUTH_SECRET ?? "dev-secret-change-in-prod",
 });