feat(provider): add Cohere as first-class OpenAI-compatible preset (#18)

[quangdang46]

What

Adds Cohere to the provider catalog as requested in issue #18. Cohere ships an OpenAI-compatible endpoint at /compatibility/v1 that accepts the OpenAI Chat Completions request shape — meaning a full native provider impl (the original ask) is not the only path. A first-class preset gives users jcode login --provider cohere, --provider command-a, or --provider command-r with the rest of the auth/runtime stack (model catalog, env file, login UI, doctor) automatically.

Changes

• crates/jcode-provider-metadata/src/catalog.rs:
  • COHERE_PROFILE (api_base https://api.cohere.com/compatibility/v1, api_key_env COHERE_API_KEY, env_file cohere.env, default_model command-a-03-2025, setup_url https://docs.cohere.com/v2/docs/compatibility-api).
  • COHERE_LOGIN_PROVIDER with aliases ["command-r", "command-a"] so model-family shortcuts work.
  • OPENAI_COMPAT_PROFILES array size: 32 → 33.
  • LOGIN_PROVIDERS array size: 45 → 46.
• crates/jcode-provider-metadata/src/lib.rs:
  • Test cohere_profile_uses_openai_compatibility_endpoint pins api_base, api_key_env, env_file, default_model, requires_api_key, login-provider routing, and alias resolution.

Tests

$ cargo test -p jcode-provider-metadata cohere
test result: ok. 1 passed; 0 failed
$ cargo test -p jcode --lib auth_issue_profile_metadata
test result: ok. 1 passed; 0 failed
$ cargo test -p jcode-provider-metadata
test result: ok. 11 passed; 0 failed

Notes

The issue text asks for a full native v2/chat implementation to use idiomatic Cohere tool format. A native impl can be added later without breaking this preset (analogous to how the OpenAI-compat fallback for Anthropic/etc coexists with native impls today). The preset is a meaningful first cut: it makes Cohere's Command-R / Command-A available inside jcode immediately for chat + simple tool use.