Agent Skills: go-profiling-optimization

Profile and optimize Go performance: pprof CPU/memory/block/mutex profiles, allocation analysis, escape analysis, sync.Pool, GOGC/GOMEMLIMIT tuning, benchmarks with -benchmem, PGO workflow, execution tracing. Use when user asks 'why is this slow', 'is this allocating', mentions pprof/profiling, runs benchmarks, or needs to reduce p99 latency. SKIP for general Go idioms — use `go` skill.