fix: tailwind v4 postcss, auth-server session, eslint cleanups

frontend/lib/auth-server.js

@@ -0,0 +1,42 @@
+// File: frontend/lib/auth-server.js
+// frontend/lib/auth-server.js
+import 'server-only';
+import { cookies } from 'next/headers';
+
+export function getAccessToken() {
+  const cookieStore = cookies();
+  return cookieStore.get('access_token')?.value ?? null;
+}
+
+function buildCookieHeader() {
+  const store = cookies();
+  return store.getAll().map(c => `${c.name}=${c.value}`).join('; ');
+}
+
+export async function getSession() {
+  const token = getAccessToken();
+  if (!token) return null;
+
+  try {
+    const res = await fetch(`${process.env.NEXT_PUBLIC_API_BASE}/api/auth/me`, {
+      method: 'GET',
+      headers: { cookie: buildCookieHeader(), accept: 'application/json' },
+      cache: 'no-store',
+    });
+    if (!res.ok) return null;
+    const data = await res.json();
+    const user = data?.user ?? data; // รองรับทั้ง {user:{...}} หรือส่งตรง
+    return { user, token };
+  } catch {
+    return null;
+  }
+}
+
+export async function requireSession() {
+  const session = await getSession();
+  if (!session) {
+    const { redirect } = await import('next/navigation');
+    redirect('/login');
+  }
+  return session;
+}