The opencode provider test asserted models with "openai/" or
"openrouter/openai/" prefixes, but these are environment-dependent —
opencode returns whatever providers are connected, and CI may not have
OpenAI configured. Replace with a generic check that at least one
non-opencode/ namespaced model exists.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>