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/lib/drupal.ts

@@ -0,0 +1,20 @@
+import { NextDrupal } from "next-drupal"
+
+const baseUrl = process.env.NEXT_PUBLIC_DRUPAL_BASE_URL!
+
+const auth =
+  process.env.DRUPAL_CLIENT_ID && process.env.DRUPAL_CLIENT_SECRET
+    ? {
+        clientId: process.env.DRUPAL_CLIENT_ID,
+        clientSecret: process.env.DRUPAL_CLIENT_SECRET,
+        ...(process.env.DRUPAL_OAUTH_SCOPE && {
+          scope: process.env.DRUPAL_OAUTH_SCOPE,
+        }),
+      }
+    : undefined
+
+export const drupal = new NextDrupal(baseUrl, {
+  auth,
+  withAuth: !!auth,
+  debug: process.env.NODE_ENV === "development",
+})