Agent Skills: review-perf

General application performance review for non-Django code (Flask, FastAPI, Go, Node, generic Python). Use when asked to "review performance", "audit performance", "find slow code", "perf review", or audit app-tier code for blocking I/O on async paths, algorithmic blow-ups, per-item network loops, unbounded memory accumulation, or missing application caching. Find-only — use `optimize-perf` to apply fixes with benchmarks. Covers the application surface that `review-django-perf` (Django ORM) and `sql-reviewer` (raw SQL / migrations) do not. Validation-first — no flag without traced evidence.