Make email handling case-insensitive (queries + model normalization) to prevent duplicate accounts. Add SiteDomainService.panel_origin() helper and use it across services to build public URLs (Gitea, WordPress, Roundcube) and Django ALLOWED_HOSTS. Add optional custom-domain support when creating WordPress sites and propagate domain to Roundcube install. Improve environment domain fallback to prefer panel/base domains over .localhost. Small Dockerfile healthcheck tweak (use 127.0.0.1). Update install/update/build scripts to always (re)create virtualenv locally for release installs. Remove unused frontend CreateSiteModal and expose domain field in WordPress page.
