Add Drupal headless stack with Next.js frontend

- Add Next.js frontend service (nextjs) with Dockerfile and source
- Update docker-compose.yml: image names, Drupal 11.3.3, nextjs service
- Add docker-compose.override.yml.disabled for dev hot-reload
- Add install-headless-modules.sh for OAuth/JSON:API module setup
- Add README.md with full setup and configuration guide
- Update nginx/Dockerfile and nginx.conf.template for cms. subdomain
- Update drupal/Dockerfile PHP-FPM build args
- Gitignore **/.vscode/ to prevent IDE workspace files from being tracked

drupal/nextjs/components/node-article.tsx

@@ -0,0 +1,35 @@
+import type { DrupalNode } from "@/lib/types"
+
+interface NodeArticleProps {
+  node: DrupalNode
+}
+
+export function NodeArticle({ node }: NodeArticleProps) {
+  return (
+    <article className="mx-auto max-w-4xl">
+      <h1 className="mb-4 text-4xl font-bold tracking-tight text-emerald-600">
+        {node.title}
+      </h1>
+      <div className="mb-8 flex items-center gap-3 text-sm text-slate-600">
+        {node.uid?.display_name && (
+          <span>By {node.uid.display_name}</span>
+        )}
+        <time dateTime={node.created}>
+          {new Date(node.created).toLocaleDateString("en-US", {
+            year: "numeric",
+            month: "long",
+            day: "numeric",
+          })}
+        </time>
+      </div>
+      {(node.body?.processed ?? node.body?.value) && (
+        <div
+          className="pemerald pemerald-slate max-w-none pemerald-a:text-emerald-600 pemerald-a:underline hover:pemerald-a:text-emerald-500"
+          dangerouslySetInnerHTML={{
+            __html: node.body.processed ?? node.body?.value ?? "",
+          }}
+        />
+      )}
+    </article>
+  )
+}