feat: initial project setup for Meme Studio

Next.js 14 App Router application for managing homophone pun game levels:

- Better Auth with Prisma adapter for authentication
- MySQL database with Prisma ORM
- Level CRUD operations with drag-and-drop reordering
- Tencent COS integration for image uploads
- shadcn/ui components with Tailwind CSS
- TanStack Query for server state management

middleware.ts

@@ -0,0 +1,35 @@
+import { NextRequest, NextResponse } from 'next/server'
+
+export async function middleware(request: NextRequest) {
+  const { pathname } = request.nextUrl
+
+  // Allow auth API routes and static files
+  if (
+    pathname.startsWith('/api/auth') ||
+    pathname.startsWith('/_next') ||
+    pathname.startsWith('/favicon') ||
+    pathname.includes('.')
+  ) {
+    return NextResponse.next()
+  }
+
+  // Allow login page
+  if (pathname === '/login') {
+    return NextResponse.next()
+  }
+
+  // Check if session cookie exists (simple check, full validation happens in server)
+  const sessionToken = request.cookies.get('better-auth.session_token')
+
+  if (!sessionToken?.value) {
+    const loginUrl = new URL('/login', request.url)
+    loginUrl.searchParams.set('callbackUrl', pathname)
+    return NextResponse.redirect(loginUrl)
+  }
+
+  return NextResponse.next()
+}
+
+export const config = {
+  matcher: ['/((?!api/auth|_next/static|_next/image|favicon.ico).*)'],
+}