Caveman Setup skill: what it does and how to install it

What it does. Finds live LLM callsites, routes them through Caveman with the appropriate gateway and provider-key headers, and stores credentials in environment variables. It derives an app slug, supports stored or BYOK provider keys, then verifies the wiring with one small real request and reports its usage.

When to use it. Applies when adding Caveman spend observability to a repository with existing LLM calls. It stops without changes when no callsites are found and reports the integration as unverified if the gateway or provider request fails.