Antigravity support rebuilt on Google's own ACP binary

[Takalele]

The old google-antigravity provider spoofed Cloud Code Assist traffic and held Google credentials inside omp. That path is gone, for ToS reasons.

What replaces it: a new antigravity provider that spawns Google's official Antigravity ACP binary as a model. omp manages the binary (omp antigravity install|update|remove|status), relays the binary's own Google sign-in through /login antigravity, and streams turns over ACP. No Google tokens in omp, oauth-personal only, honest clientInfo, no quota scraping. Plan-Gemini models show up in the picker like any other provider.

The compliance question was answered on the board: Google staff confirmed in writing that running the unmodified official antigravity-acp binary from the ACP Registry, signed in through its native oauth-personal flow, is permitted for single-user interactive development — while token extraction, proxying, and wrapping agy -p in third-party loops stay banned. That ruling is exactly the architecture this provider implements: https://discuss.ai.google.dev/t/tos-clarification-is-t3-code-official-antigravity-acp-agent-permitted-under-the-antigravity-terms-of-service/192027

The part I'd like eyes on is rendering. The binary runs edits and commands itself, in your working directory, so omp mirrors those calls as ordinary tool cards. Two things needed fixing, and both also affect Cursor's server-executed cards:

• Auto-approved runs execute under a different toolCall id whose frames never carry a diff; the diff only exists on the permission echo. The echo is now linked to the execution frame by kind and target, so the edit card shows its diff.
• Provider-executed results arrive as bare message_end messages, so the live card never settled and streamed forever. The event controller now attaches the result at message_end.

Suites: ai 6682/0, tui 4222/0, utils 956/0, catalog 1273/0, coding-agent clean apart from pre-existing load flakes. Live runs against the real 1.4.5 binary confirm diff cards, command output, and files on disk.

The code is up for testing and review at feat/antigravity-acp-compliance — build it, run it against your Antigravity account, and tell me what you find. If it holds up for you, I'll open the PR against upstream.

[CREAsTIVE]

Any updates on that?