feat: LLM provider for Grok

[3byss]

Summary

Added a file for a provider for the Grok AI, changed documentation for the introduction of the Grok provider, and implemented tests for grok

Additions

• lib/llm/grok.mjs
• test/llm-grok.test.mjs

Updated

• README.md
• lib/llm/index.mjs
• .env.example
• crucix.config.mjs

All configurations in a .env file are the same no additional information needed to run the provider

Addresses issue #54

[calesthio]

Thanks for opening this. Adding a Grok provider makes sense, but there are a few issues I think should be fixed before this is merged:

1. The Grok provider currently ignores opts.maxTokens. Every existing remote provider forwards that option, and the main call sites rely on it to bound outputs for trade ideas and alert evaluation. With LLM_PROVIDER=grok, those caps silently stop applying, which can increase latency/cost and produce oversized generations. Please pass through max_tokens here like the other providers do.

2. The response parsing is not null-safe in the same way as the other providers. data.choices?.[0].message?.content will throw if choices is an empty array, because [0] is not optional-chained before .message. Please change this to match the other providers so a 200 response with no choices degrades cleanly instead of breaking the sweep.

3. The default model should be updated. Right now this provider defaults to grok-3, but xAI?s current docs recommend the latest alias approach and their current flagship family is Grok 4. grok-4-latest should be the recommended default/model guidance here instead of grok-3, and the docs/config comments should be updated consistently.

There are also a couple README references that still list the old provider count/provider set, so those should be brought back into sync while you?re here.

[calesthio]

Applied the remaining fixes directly to this PR branch before approving. Specifically: wired the Grok provider to the shared \maxTokens\ interface, updated and expanded the Grok tests to cover the new default model and request payload, and synced the README so Grok is documented consistently with the other providers.