Add Docker deployment option for the server with multi-stage build.
Changes:
- Dockerfile: multi-stage build (golang:1.26-alpine → alpine:3.21, ~23MB)
- docker-compose.yml: server service on port 5300/udp with iptables redirect
- .env.example: documented environment variables template
- .dockerignore: optimized build context
- README.md & README-FA.md: Docker deployment guide, port 53 safety checks,
and troubleshooting instructions (both EN and FA)
- configs: added more Telegram channels and X accounts
The container listens on port 5300 to avoid conflict with systemd-resolved.
External DNS traffic (port 53) is redirected via iptables PREROUTING.
No changes to existing Go source code.
- Refactor fetcher tests to improve coverage and add new tests for resolver scoring and query handling.
- Update ResolverChecker to retry every minute until a healthy resolver is found and adjust timeout settings.
- Introduce scatter parameter in the configuration to allow concurrent DNS requests, with UI adjustments for user input.
- Modify metadata fetching logic to utilize cached data efficiently and ensure fresh data is fetched when necessary.
- Implement server-side handling for fetch progress, including countdowns and UI updates during long fetch operations.