feat: add checkout domain verification status from api-specifications#2416

[cursor]

Summary

Adds the public Checkout Domains resource and folds in the pending DX-906 baseline so the status change from api-specifications#2416 is available in the Node SDK.

The public approval-status union includes action_required and verification_in_progress, excludes internal archived, and documents the corrected meaning of in_review. This additive surface bumps the package version to 3.11.0.

Linear issue: DX-1092

Spec-to-SDK mapping

Spec change	SDK files
Add public verification_in_progress response status and revise in_review documentation	src/enums/checkout-domains/checkout-domain-approval-status.ts, src/types/checkout-domains/checkout-domain-response.ts, src/entities/checkout-domains/checkout-domain.ts
Accept verification_in_progress in the list status filter	src/resources/checkout-domains/operations/list-checkout-domains-query-parameters.ts
Add the pending public Checkout Domains baseline (list/get/delete/verify)	src/resources/checkout-domains/**, src/entities/checkout-domains/**, src/types/checkout-domains/**, src/enums/checkout-domains/**, src/paddle.ts, and root barrels
Verify response deserialization and query serialization	src/__tests__/mocks/resources/checkout-domains.mock.ts, src/__tests__/resources/checkout-domains.test.ts
Document and version the additive SDK surface	CHANGELOG.md, package.json

Intentionally excluded

• CheckoutDomainStatusUpdate and its PATCH operation remain @internalUseOnly.
• Checkout-domain create and resubmit operations remain @partnerOnly.
• archived remains excluded because it is internal in the query enum.
• No notification types, entities, event classes, or webhook mocks were added because the changed Paddle Events contracts are internal rather than released webhook payloads.

Validation

• pnpm install --frozen-lockfile — passed
• pnpm build — passed
• pnpm typecheck:tests — passed
• pnpm test --runInBand — 35 suites and 281 tests passed, including 4 Checkout Domains tests
• pnpm lint — passed
• pnpm prettier — passed

This PR was created by an automated spec-sync agent.