Fix gitignore blocking deploy override from being tracked

The pattern docker-compose.override.yml matched at all levels,
preventing website/deploy/docker-compose.override.yml from being
committed. Changed to /docker-compose.override.yml (root-only).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

website/deploy/docker-compose.override.yml

@@ -0,0 +1,11 @@
+# Marketing site overlay — adds the static marketing site to the nginx container
+# This file is auto-merged by Docker Compose when placed in the project root.
+# It does NOT modify any core WebsiteBox files.
+#
+# Usage: cp website/deploy/docker-compose.override.yml . && docker compose up -d
+
+services:
+  nginx:
+    volumes:
+      - ./website:/var/www/marketing:ro
+      - ./website/deploy/active-marketing.conf:/etc/nginx/conf.d/marketing.conf:ro