Catalog-only Provider wrapper for the OpenCode CLI. See Agentic.LLM.Provider.ClaudeCode for the design rationale.

OpenCode pulls its model list from https://models.dev/api.json — the same source Agentic.LLM.Canonical uses. We seed the catalog with a small static set covering the providers OpenCode is most often pointed at; users can extend via default_models/0 overrides.