chore: create production-v2 branch with content only

This branch contains ONLY:
- Pages (config/www/user/pages/)
- Themes (config/www/user/themes/)
- Plugins (config/www/user/plugins/)
- PRODUCTION.md
- Minimal .gitignore

Clean slate for production deployment.
All development files, configs, scripts removed.

config/www/user/plugins/error/pages/error.md

@@ -0,0 +1,14 @@
+---
+title: Page not Found
+robots: noindex,nofollow
+template: error
+routable: false
+http_response_code: 404
+twig_first: true
+process:
+  twig: true
+expires: 0
+---
+
+{{ 'PLUGIN_ERROR.ERROR_MESSAGE'|t }}
+