VS Code extension rejects non-gpt-5 model IDs and overrides Other models config (always calls gpt-5)

What version of Codex is running?

codex-cli 0.23.0

Which model were you using?

_No response_

What platform is your computer?

_No response_

What steps can reproduce the bug?

Steps to Reproduce

1. Open VS Code and set the extension to use OpenRouter with the config above.
2. Start a chat or any request from the extension.
3. Check OpenRouter usage dashboard: requests arrive as gpt-5.

What is the expected behavior?

The extension should accept arbitrary model IDs when provider is OpenRouter (e.g., anthropic/claude-sonnet-4, etc.).
Requests should be sent to the configured provider/baseUrl and use the exact model string supplied.

What do you see instead?

Settings validation only accepts "gpt-5" for chatgpt.model.
Extension sends requests to gpt-5 despite provider/model overrides pointing to OpenRouter.

Additional information

_No response_