Golang Safety

Prevents the classic Go footguns: nil interface traps, append aliasing, defer in loops, silent integer truncation, and map concurrent writes. Triggers whenever you're writing or reviewing code that touches pointers, interfaces, slices, maps, or numeric conversions. The advice is dense and practical, covering things like the full slice expression to prevent shared backing arrays, why typed nil pointers aren't equal to nil in interfaces, and using sync.Once for lazy init. Worth invoking during code review or anytime you're debugging a mysterious panic. Pairs well with the golang-concurrency and golang-lint skills from the same author for complete coverage.