[Feature request]: add support for antigravity-cli (google)

[chrillep]

▝▜▄ Gemini CLI v0.45.2
▝▜▄
▗▟▀ Signed in with Google /auth
▝▀ Plan: Gemini Code Assist for individuals /upgrade

╭───────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╮
│ Gemini CLI will stop serving requests to Google One and unpaid tiers on June 18. Please migrate to Antigravity CLI before then at │
│ https://antigravity.google/product/antigravity-cli │
│ Learn more: https://goo.gle/gemini-cli-migration