* 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.
lukaszraczylo