Refactored DnsHelper for maintainability and added automatic DNS testing for the public config hostname after creation/update of vrp-public.json to automatically enable fallback DNS and proxy if system DNS fails for that
Introduced DnsHelper to detect system DNS failures and fall back to Cloudflare (1.1.1.1 / 1.0.0.1) DNS resolving, with caching and helpers for downloads. When fallback is required a lightweight local proxy is started and HTTP_PROXY/HTTPS_PROXY are set for spawned rclone processes so rclone uses the proxy’s DNS resolution; the proxy is cleaned up on exit. This finally resolves the very common ISP DNS blockage issues of users.
