Add Command Code GOAT provider

[Astro-Han]

Summary

Adds Command Code (commandcode.ai) as a first-class provider, covering its GOAT plan.

Command Code exposes every plan model through an OpenAI-compatible provider API:

• base URL https://api.commandcode.ai/provider/v1, auth via a bearer API key from Studio (GOAT and above include API access; only the free Go plan does not)
• POST /chat/completions on the OpenAI wire and GET /models for model discovery, with streaming and end-of-stream usage

packages/core/src/provider-registry.ts registers commandcode with the standard openai-compatible "provider" runtime adapter (same shape as zenmux/opencode), kind: 'protocol' model discovery — the live /models catalog becomes authoritative once a key is saved — and a GOAT model baseline transcribed from commandcode.ai/models. Command Code is not on models.dev, so there is no generated metadata for it; the shipped list is the offline offer.

apps/desktop/src/renderer/settings/provider-display-copy.ts gains the bilingual (zh-CN / zh-TW / en) catalog card; the compile-time Record<ProviderType, …> contract requires an entry for every registered provider.

No change to existing connections; no migration.

Verification

• @maka/core: build + full suite — 816 pass (includes provider catalog contract invariants over the new entry)
• @maka/runtime: provider-conformance 26 pass; provider-contract-matrix / model-fetcher / model-adapter / provider-error-classification / model-factory — 247 pass (the conformance matrix derives rows from the registry, so commandcode is exercised generically)
• renderer tsc --noEmit clean; biome format + lint clean
• Provider catalog story (Add Connection Catalog) renders the new card via the registry-driven catalog path (DOM-checked headlessly: [data-provider="commandcode"] present only with this change)

Remaining end-to-end check: wiring a GOAT API key and sending one request. No key was available in this environment; if a keyed run surfaces a model id mismatch, the /models discovery refreshes the baseline and brokenModelIds can quarantine the id.

AI use

• No generative tool made a substantive contribution
• Generative tooling made a substantive contribution

Tool(s) and scope: Maka authored the registry entry, model baseline, catalog copy, storybook evidence, and this PR text. Both commits carry Generated-by: Maka trailers.

Checklist

• Tests cover the change and fail without it
• Lint, format, typecheck and the affected suites pass locally

Does this PR entail a change in behavior?

• Yes — the add-connection catalog now offers Command Code; described under Summary above
• No