feat: add middleware to protect admin routes with authentication check

middleware.ts

@@ -0,0 +1,24 @@
+import { NextRequest, NextResponse } from 'next/server'
+
+// Move accessToken to HttpOnly cookie in future for better security
+// Backend sets 'refreshToken' cookie on login; use it as auth presence
+const AUTH_COOKIES = ['refreshToken']
+
+export function middleware(req: NextRequest) {
+  const { pathname } = req.nextUrl
+
+  // Only guard admin routes
+  if (pathname.startsWith('/admin')) {
+    const hasAuthCookie = AUTH_COOKIES.some((name) => !!req.cookies.get(name)?.value)
+    if (!hasAuthCookie) {
+      const loginUrl = new URL('/login', req.url)
+      return NextResponse.redirect(loginUrl)
+    }
+  }
+
+  return NextResponse.next()
+}
+
+export const config = {
+  matcher: ['/admin/:path*'],
+}