Add installable PWA support

app/layout.tsx

@@ -1,5 +1,6 @@
 import type { Metadata } from "next";
 import "./globals.css";
+import PwaRegister from "./pwa-register";
 
 export const metadata: Metadata = {
   title: "大学英语六级 · 90天打卡",
@@ -8,6 +9,9 @@ export const metadata: Metadata = {
     icon: "/favicon.svg",
     shortcut: "/favicon.svg",
   },
+  manifest: "/manifest.webmanifest",
+  applicationName: "大学英语六级 · 90天打卡",
+  themeColor: "#1d4ed8",
 };
 
 export default function RootLayout({
@@ -17,7 +21,7 @@ export default function RootLayout({
 }>) {
   return (
     <html lang="zh-CN">
-      <body className="antialiased">{children}</body>
+      <body className="antialiased"><PwaRegister />{children}</body>
     </html>
   );
 }