- Implement --proxy <url> CLI option for configuring HTTP(S) or SOCKS proxy
- Add proxy handling in argument parsing with proper validation
- Update documentation in COMPILER_CLI.md, README.md, and README-CN.md
- Enhance Downloader class to support proxy configuration for curl commands
- Add stream context options for HTTP proxy with authentication support
- Include proxy error message sanitization to hide sensitive information
- Add unit tests for proxy functionality covering curl and stream scenarios
- Update bash completion script to include new --proxy option
- Validate proxy URL requirements with appropriate error messages