* gosec govulncheck runs
* Fix flaky TestRateLimiter_Matrix test
The test was failing due to two issues:
1. Test name generation used invalid character conversion (string(rune('0'+limit)))
which produced non-printable characters for limits >= 10
2. Using 10ms windows with 100 requests caused race conditions - early requests
would expire before all 100 were made, allowing the 101st request
Changed to use struct-based test cases with proper fmt.Sprintf naming and
a consistent 1-second window that won't expire during rapid test execution.
The verified parameter is only needed when the URL domain differs
from the homepage domain. Since both point to github.com, Homebrew
audit flags this as unnecessary.