fix(ai): route Copilot Grok 4.5 to responses

[jay-tau]

Summary

• Route GitHub Copilot grok-4.5 through the OpenAI Responses API.
• Regenerate the Copilot model catalog and add regression coverage.

Testing

• npx tsx ../../node_modules/vitest/dist/cli.js --run test/github-copilot-models.test.ts
• npm run check

Fixes #875

Note

Route GitHub Copilot grok-4.5 to the Responses API instead of Chat Completions

The grok-4.5 model under the github-copilot provider does not support the Chat Completions endpoint, so it is now assigned openai-responses in generate-models.ts alongside the existing gpt-5 and oswe models. The generated catalog and a new test in github-copilot-models.test.ts confirm the correct routing.

^{Macroscope summarized 76b84a2.}

[kevinjosethomas]

Hi, thanks for taking the time to contribute to Prime Agent! Since open sourcing the project, we’ve received far more pull requests than we can responsibly review and validate. Prime Agent runs directly on users’ machines, so we need to be deliberate about which changes we accept and how they are reviewed. Rather than leave a large backlog that we cannot meaningfully work through, we’re closing the current PR queue and moving to a discussion-first contribution process.

We have established new contribution guidelines to help us continue iterating on Prime Agent and better manage contributions from the community. Going forward, we won’t review unsolicited pull requests. Instead, please start with a GitHub Discussion. We’ll identify recurring bugs and feature requests, create Issues for work we want to pursue, and invite pull requests from maintainers or vouched contributors when implementation is ready. Please read the full process documented in our contribution guidelines.

While we’re closing this backlog, we’re still reviewing it at a high level to identify recurring bugs, useful ideas, and important problems that we should address ourselves. Thanks again for the time you put into this!