Claude Opus 4.5 has been replaced by Claude Opus 4.6 on the
Antigravity (Google Cloud Code Assist) platform.
- Update model definition in generate-models.ts
- Update generated models output
The process.env access was outside the typeof process check, which
would throw in browser environments. Moved inside the Node.js/Bun
block for consistency with other env var access.
Also added changelog entry for #1320 and improved docs clarity.