Is your feature request related to a problem? Please describe.

The current fixed output format [LIVE] [US] [203.0.113.1] http://proxy.example.com:8080 (245ms) makes it difficult to:

• Parse output programmatically for automation workflows
• Generate CSV or JSON formats for data analysis
• Extract specific fields w/o complex regex parsing
• Integrate with monitoring systems that expect structured data
• Create custom reports with only the information I need
• Currently, users have to write custom parsers or use complex text processing tools to extract useful information from the checker output, which is time-consuming and error-prone.

Describe the solution you'd like

Introduce a --output-format flag that allows customizable output formatting using template syntax. This would enable users to define exactly what information they want and how it should be formatted.

Describe alternatives you've considered

N/A

Additional context

This feature would significantly improve mubeng's usability in automated environments and integration scenarios. Many users need to feed proxy checker results into:

• Monitoring dashboards (requiring JSON/structured data)
• Spreadsheet analysis (requiring CSV format)
• Other security tools (requiring simple proxy lists)
• Custom reporting systems (requiring specific formatting)