feat: add Grocy kitchen ERP service

- Add grocy subdomain to domains.yml
- Create Docker Compose template using LinuxServer image
- Add Ansible task for service deployment
- Configure Caddy reverse proxy with Authentik auth and API bypass
- Add DNS record for grocy subdomain
- Integrate with productivity services category

🤖 Generated with [Claude Code](https://claude.ai/code)

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

roles/docker/tasks/productivity/main.yml

@@ -35,4 +35,8 @@
 
 - name: Install kanboard
   import_tasks: kanboard.yml
-  tags: kanboard
+  tags: kanboard
+
+- name: Install grocy
+  import_tasks: grocy.yml
+  tags: grocy