Migrate the Gemini engine to Antigravity CLI

[Copilot]

This change makes the Google engine migration explicit and breaking: engine: gemini is removed, engine: antigravity becomes the supported replacement, execution moves to agy, and workflows now require ANTIGRAVITY_API_KEY. It also adds codemod support so repository workflows, scripts, tests, docs, and generated references can be rewritten consistently.

• Engine/runtime migration

  • Replaces the Gemini runtime entry with antigravity in the engine registry, catalog, constants, and built-in engine definition.
  • Switches command generation from gemini to agy.
  • Renames engine-specific runtime files, log parser hooks, MCP config writers, artifact names, and engine metadata from Gemini to Antigravity.

• Breaking failure mode

  • Adds an explicit migration diagnostic for legacy frontmatter:
    • engine: gemini is no longer supported. Run the Antigravity migration codemod and configure ANTIGRAVITY_API_KEY.
  • Rejects legacy inline/runtime engine definitions that still resolve to gemini.

• Credential migration

  • Moves the engine secret from GEMINI_API_KEY to ANTIGRAVITY_API_KEY.
  • Updates secret validation to fail fast when only GEMINI_API_KEY is present, instead of silently accepting legacy configuration.
  • Renames model/base-url/trust env vars to Antigravity equivalents.

• Setup, MCP, and log parsing

  • Renames Gemini-specific setup assets to Antigravity equivalents:
    • gateway config conversion
    • log parsing
    • workspace config directory
    • engine-specific settings output
  • Keeps the same integration shape for MCP/tool config, but writes it under .antigravity/settings.json.

• Codemod support

  • Adds scripts/antigravity_codemod.py for repository-wide migration with:
    • dry-run mode
    • write mode
    • changed file list output
    • diff output
    • failure summary
  • Rewrites engine IDs, credentials, CLI references, config paths, and related text references across tracked text files.

• Tests and generated references

  • Renames engine-focused tests and fixtures to Antigravity terminology.
  • Updates generated engine references and smoke workflow naming to the new engine.

Example migration:

# before
engine: gemini
env:
  GEMINI_API_KEY: ${{ secrets.GEMINI_API_KEY }}
run: gemini --prompt "$(cat prompt.txt)"

# after
engine: antigravity
env:
  ANTIGRAVITY_API_KEY: ${{ secrets.ANTIGRAVITY_API_KEY }}
run: agy --prompt "$(cat prompt.txt)"

---

pr-sous-chef: updated branch via run 26382126309.

Generated by 👨‍🍳 PR Sous Chef · gpt54 2.2M · ◷

[pelikhan]

@copilot implement codemod in go using existing codemod infrastructure

[Copilot]

@copilot implement codemod in go using existing codemod infrastructure

Implemented in 0fba22e: the standalone Python script is replaced with a Go codemod registered in the existing gh aw fix codemod registry, the Gemini deprecation guidance now points to gh aw fix --write, and the smoke Antigravity workflow/lockfile were refreshed to remove the remaining Gemini-era references.

[pelikhan]

@copilot rename smoke-Gemini to smoke-antigravity, update cli version checker

[Copilot]

@copilot rename smoke-Gemini to smoke-antigravity, update cli version checker

Addressed in 295d650: renamed the remaining smoke Antigravity prompt text/file names and updated the CLI version checker to include Antigravity CLI plus the correct version constants source.

[pelikhan]

@copilot track all occurrences of Gemini and upgrade if necessary. Keep codemod and historical blogs, docs. Add note in docs that Gemini is now antigravity

[Copilot]

@copilot track all occurrences of Gemini and upgrade if necessary. Keep codemod and historical blogs, docs. Add note in docs that Gemini is now antigravity

Addressed in 6bc8972: swept the remaining non-historical Gemini references, kept the migration codemod/legacy diagnostics intact, added docs notes that Gemini is now Antigravity, renamed the daily model inventory Antigravity collector job, and refreshed the generated lockfile and WASM goldens.

[Copilot]

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[pelikhan]

@copilot merge main and recompile

[Copilot]

@copilot merge main and recompile

81d10d5: main was already merged into this branch, so I recompiled the generated workflow output and also removed the leftover merge markers in the CLI tests that validation surfaced.

[pelikhan]

@copilot review all changes

[Copilot]

@copilot review all changes

Reviewed the branch and fixed two real issues in 33844cd: Antigravity secret validation now respects engine.env overrides, and the built-in Antigravity model alias fallback chain/goldens were corrected. Re-ran go test ./pkg/workflow ./pkg/cli and make test-wasm-golden.

[pelikhan]

@copilot GEMINI_API_KEY is outdated and should not be supported anymore.

[Copilot]

@copilot GEMINI_API_KEY is outdated and should not be supported anymore.

Addressed in e71d991: Antigravity no longer wires GEMINI_API_KEY into its validation step, and the regenerated smoke workflow now requires only ANTIGRAVITY_API_KEY.