Add Atlas Cloud as a built-in provider

[binyangzhu000-sudo]

Summary

• add Atlas Cloud as a built-in OpenAI-compatible provider with https://api.atlascloud.ai/v1, ATLASCLOUD_API_KEY, and qwen/qwen3.5-flash as the default model
• wire Atlas Cloud through provider validation, key-prefix detection, onboarding IPC parsing, provider shortlist, public base-url fallback, and provider error help URLs
• update the existing English/Chinese provider lists only; no sponsor blocks, logos, credits, or partner copy were added

Validation

• vitest run packages/shared/src/config.test.ts packages/shared/src/base-url.test.ts packages/providers/src/index.test.ts packages/providers/src/validate.test.ts packages/core/src/errors.test.ts apps/desktop/src/main/onboarding-ipc.test.ts (228 tests passed)
• biome check on changed source/test/README files
• tsc --noEmit for packages/shared, packages/providers, packages/core, and apps/desktop/tsconfig.node.json
• live Atlas Cloud /v1/models check returned 118 models, including qwen/qwen3.5-flash and deepseek-ai/deepseek-v4-pro
• commit hook ran full-repo biome check . successfully

Note: the repository pre-push hook runs the full test suite. In this local environment, desktop suites that import Electron fail because Electron's install script is blocked by pnpm's approve-builds policy (Electron failed to install correctly). The targeted provider/onboarding tests and typechecks above pass.

[github-actions]

Review mode: initial

Findings

• [Minor] Missing changeset for a user-visible change — Atlas Cloud is a new built-in provider that appears in onboarding, settings, model picker, and provider lists. According to the project conventions (CONTRIBUTING.md, PR template checklist), every user-visible change should include a changeset via pnpm changeset. Without one, the changelog will not reflect this addition for users who upgrade.
  Suggested fix: run pnpm changeset with a patch-level bump and a description such as "feat: add Atlas Cloud as a built-in OpenAI-compatible provider" before merging.

• [Nit] The PROVIDER_KEY_HELP_URL entry for Atlas Cloud (https://atlascloud.ai/) is a generic landing page, not a direct key-settings URL. While acceptable as a starting point, consider updating it to the exact key-management page if Atlas Cloud provides one (e.g., https://atlascloud.ai/account/api-keys). This would reduce user friction when they encounter a 4xx error and click the link.

Summary

The PR cleanly adds Atlas Cloud as a built-in OpenAI-compatible provider across all relevant layers (config schema, onboarding IPC, provider validation, key-prefix detection, error rewriting, base URL models endpoint, provider shortlist, and documentation). The changes are additive, follow existing patterns, and include tests for each new path. No regressions, security issues, or dependency/license concerns were identified. The only actionable item before merging is adding a changeset for changelog tracking.

Testing

• New test cases added for key detection (packages/providers/src/index.test.ts), provider validation (packages/providers/src/validate.test.ts), onboarding IPC forwarding (apps/desktop/src/main/onboarding-ipc.test.ts), error URL rewriting (packages/core/src/errors.test.ts), base URL models endpoint (packages/shared/src/base-url.test.ts), and config schema/shortlist (packages/shared/src/config.test.ts). Existing tests continue to pass. No E2E tests for Atlas Cloud-specific UI workflows (e.g., onboarding flow with Atlas Cloud selected) — acceptable for an initial integration.

Open-CoDesign Bot

[github-actions]

Review mode: follow-up after new commits

Findings

• [Resolved] The missing changeset (previously [Minor]) is now present at .changeset/atlascloud-provider.md. Thank you.

Residual observations

• The key-help URL for Atlas Cloud (https://atlascloud.ai/) remains a generic landing page rather than a direct key-management link. This is a non-blocking polish item — if Atlas Cloud provides a dedicated key-settings URL (e.g., https://atlascloud.ai/account/api-keys), consider updating it to reduce user friction on 4xx errors.

Summary
All material issues from the previous review are resolved. The PR correctly wires Atlas Cloud across config, onboarding, validation, error rewriting, and documentation. Tests cover each new path. No regressions or security concerns. Ready to merge.

Testing

• Existing tests pass; the new changeset does not affect runtime.

Open-CoDesign Bot