Cross-model benchmark for gstack skills. Runs the same prompt through Claude,
GPT (via Codex CLI), and Gemini side-by-side — compares latency, tokens, cost,
and optionally quality via LLM judge. Answers "which model is actually best
for this skill?" with data instead of vibes. Separate from /benchmark, which
measures web page performance. Use when: "benchmark models", "compare models",
"which model is best for X", "cross-model comparison", "model shootout". (gstack)
Voice triggers (speech-to-text aliases): "compare models", "model shootout", "which model is best".
