feat: 配置 NextAuth.js 认证系统

- 支持邮箱密码登录
- 支持 Magic Link 登录（Resend）
- 配置 Session Provider
- 添加 TypeScript 类型定义

src/app/api/auth/[...nextauth]/route.ts

@@ -0,0 +1,6 @@
+import NextAuth from 'next-auth';
+import { authOptions } from '@/lib/auth';
+
+const handler = NextAuth(authOptions);
+
+export { handler as GET, handler as POST };

src/app/layout.tsx

@@ -6,6 +6,7 @@ import { WebVitals } from "@/components/analytics/web-vitals";
 import { OrganizationSchema, WebsiteSchema } from "@/components/seo/structured-data";
 import { MobileTabBar } from "@/components/layout/mobile-tab-bar";
 import { ErrorBoundary } from "@/components/ui/error-boundary";
+import { SessionProvider } from "@/providers/session-provider";
 
 const geistSans = Geist({
   variable: "--font-geist-sans",
@@ -136,11 +137,13 @@ export default function RootLayout({
         style={{ fontFamily: "'Noto Sans SC', 'Geist', -apple-system, BlinkMacSystemFont, sans-serif" }}
       >
         <WebVitals />
-        <ThemeProvider>
-          <ErrorBoundary>
-            {children}
-          </ErrorBoundary>
-        </ThemeProvider>
+        <SessionProvider>
+          <ThemeProvider>
+            <ErrorBoundary>
+              {children}
+            </ErrorBoundary>
+          </ThemeProvider>
+        </SessionProvider>
         <MobileTabBar />
       </body>
     </html>