Switch repository references from rustdesk/rustdesk-server to lejianwen/rustdesk-server across container templates and installers. Updated GitHub API release lookups, download URLs (zip for Alpine) and fetch_and_deploy_gh_release targets so hbbs/hbbr/utils packages come from lejianwen's builds. Added frontend info explaining the change for API (SSO/OAuth) compatibility and updated source header comments accordingly.
* update selfhst icon-URLs to use @master path
Changed all icon URLs in JSON files from 'cdn.jsdelivr.net/gh/selfhst/icons/webp/' to 'cdn.jsdelivr.net/gh/selfhst/icons@master/webp/' for consistency and to ensure the latest icons are referenced.
* added missing icons
