Refactor user management in Ansible playbooks to standardize on keeper_user

- Updated user addition tasks across multiple playbooks (mcp_switchboard, mcpo, neo4j, neo4j_mcp, openwebui, postgresql, rabbitmq, searxng, smtp4dev) to replace references to ansible_user and remote_user with keeper_user.
- Modified PostgreSQL deployment to create directories and manage files under keeper_user's home.
- Enhanced documentation to clarify account taxonomy and usage of keeper_user in playbooks.
- Introduced new deployment for Agent S, including environment setup, desktop environment installation, XRDP configuration, and accessibility support.
- Added staging playbook for preparing release tarballs from local repositories.
- Created templates for XRDP configuration and environment activation scripts.
- Removed obsolete sunwait documentation.

ansible/searxng/deploy.yml

@@ -22,9 +22,9 @@
       group: "{{searxng_group}}"
       system: true
 
-  - name: Add group searxng to ansible_user
+  - name: Add group searxng to keeper_user
     ansible.builtin.user:
-      name: "{{ansible_user}}"
+      name: "{{keeper_user}}"
       groups: "{{searxng_group}}"
       append: true