[FEATURE] Sharable Results

## Feature Summary
Enable users to export and share their DNS benchmarking results in multiple formats—Markdown, JSON, HTML, and image. Users can optionally input their ISP name, which, along with the test data (like download speed and resolver used), can be stored anonymously. Over time, this aggregated data can be used to build a global DNS performance map for public insight.

## Problem Statement
Users currently get local test results, but there's no easy way to:

- Share those results with others or teams
- Compare their results against others in similar regions/ISPs
- Contribute to a larger understanding of DNS resolver performance globally

Without a share/export feature and optional result submission, the value of these tests remains limited to single-user context.

Proposed Solution
Allow users to export results in:

📄 Markdown (for GitHub sharing)
🧾 JSON (for automation)
🌐 HTML (for self-hosted dashboards or copy-paste)
🖼️ Image (screenshot-style card to share on social media or Telegram)
Prompt users (optional) to input:
ISP name
City(optional or auto-detected)
With permission, submit anonymized data (DNS, download time, resolver IP, ISP) to a central backend
Display an interactive map or chart of global DNS performance trends, with filters like resolver name, ISP, Average download speed

## Additional Context
Similar projects: [speedtest.net](https://www.speedtest.net/) for ISPs, [dnsperf](https://www.dnsperf.com/) for resolver latency

Could also generate a badge like:

Users on Telegram/Discord groups often want a quick visual to compare DNSs—this can serve that use case too