## What changed
Set `plugins_mcp.product_sku` to `"codex"` in cloud thread prewarm requests for both default environments and selected projects.
## Testing
Update request payload assertions to verify the Codex plugins configuration alongside managed environment defaults, model overrides, and deferred project readiness.
GitOrigin-RevId: c4ab95aa8e3440c816c5cd136444a038f4532eb9