feat(domain-hunter): complete formula for domain-hunter

## Summary

The `domain-hunter` formula is currently incomplete and contains template placeholder values that fail Homebrew's linting checks.

## Current State

The formula at `Formula/d/domain-hunter.rb` has the following issues:
- Empty `desc` (description)
- Empty `homepage` (should start with http/https)
- Template comments not removed
- Empty `license`

## Required Changes

1. Add a proper description
2. Set homepage to `https://github.com/aRustyDev/domain-hunter`
3. Remove all template comments
4. Set the correct license
5. Add proper `url` and `sha256` for a release (not just `head`)
6. Update the `test` block with a real test

## References

- Upstream repo: https://github.com/aRustyDev/domain-hunter
- [Homebrew Formula Cookbook](https://docs.brew.sh/Formula-Cookbook)

Start with Formula/d/domain-hunter.rb and compare its structure with the Homebrew Formula Cookbook. Check the upstream domain-hunter repository for a released version, license, executable behavior, and a suitable test command. Done means the formula has populated metadata, a release url and sha256, no template comments, and a real passing test that satisfies Homebrew linting.

Written by the indexing model from the issue text.