#21257: # feat: add Gemini 3.1 Pro (low/high reasoning) model support

## Summary This PR implements **Gemini 3.1 model support** for: - `google` (Google API provider) - `google-antigravity` The goal is to make Gemini 3.1 usable through OpenClaw’s existing model selection, catalog, and fallback paths for those two providers. ## What this adds - Gemini 3.1 forward-compat resolution for `google` and `google-antigravity` - Gemini 3.1 catalog synthesis so models appear even when upstream discovery still exposes Gemini 3 templates - Gemini 3.1 model listing synthesis in `models list` - Google-provider normalization alignment: Gemini 3.1 aliases follow the same preview-ID normalization pattern used by existing Google models ## Provider Scope Implemented in this PR: - `google` - `google-antigravity` Not implemented in this PR: - `google-gemini-cli` Gemini 3.1 Reason: current upstream Cloud Code Assist responses for Gemini 3.1 are not reliably available in this environment (404 `Requested entity was not found`). This PR stays focused on the providers that are validated and working. ## Change Type - [x] Feature - [x] Bug fix - [ ] Refactor - [ ] Docs - [ ] Security hardening - [ ] Chore/infra ## Scope - [x] Gateway / orchestration - [x] Integrations - [x] UI / DX (model catalog/list visibility) - [ ] Skills / tool execution - [ ] Auth / tokens - [ ] Memory / storage - [ ] API / contracts - [ ] CI/CD / infra ## Linked Issue/PR - Closes #21176 ## User-visible behavior - `google` now accepts and resolves Gemini 3.1 IDs through forward-compat behavior. - `google-antigravity` resolves Gemini 3.1 aliases to runtime-safe low/high IDs. - Gemini 3.1 entries now appear in model catalog/listing for these providers when templates exist. ## Verification ### Tests run - `pnpm exec vitest run --config vitest.unit.config.ts src/agents/model-forward-compat.test.ts src/agents/model-catalog.test.ts src/commands/models.list.test.ts` - Passed: 3 files, 36 tests - `pnpm exec vitest run --config vitest.e2e.config.ts src/agents/models-config.normalizes-gemini-3-ids-preview-google-providers.e2e.test.ts` - Passed: 1 file, 1 test - `pnpm exec vitest run --config vitest.e2e.config.ts src/agents/pi-embedded-runner.applygoogleturnorderingfix.e2e.test.ts` - Passed: 1 file, 2 tests - `pnpm exec vitest run --config vitest.unit.config.ts src/media-understanding/providers/google/video.test.ts src/providers/google-shared.preserves-parameters-type-is-missing.test.ts` - Passed: 2 files, 11 tests ### Smoke check - `pnpm openclaw models list --provider google --all --json` - Confirmed Gemini 3.1 entries are listed for `google`. ### Not verified - Live inference against Google API with production credentials (credentials not configured in this environment). - `google-gemini-cli` Gemini 3.1 live calls (out of scope for this PR). ## Compatibility / Migration - Backward compatible: `Yes` - Config/env changes required: `No` - Migration required: `No`