- Add download_candidates helper in core/url.uc to auto-generate ghproxy mirror URLs (ghproxy.net, mirror.ghproxy.com, gh-proxy.com) for GitHub and external downloads
- Enhance download_to_file and download_subscription to try mirror candidates if direct download fails due to DPI or blocking
- Fallback to disk cache if all download attempts fail, preventing sing-box and service crashes on network outages
- Add 'Load Current Records' button in UI hosts import modal to pre-fill editor from saved configuration
- Synchronize localization catalogs