sku v13: Explicitly define entrypoints via `package.json#exports`

[askoufis]

This enforces the newly documented API entrypoints.

[changeset-bot[bot]]

🦋 Changeset detected

Latest commit: cf8d944f5b914c05c3ca4794cd994b13b56904d2

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

| Name | Type | | ---- | ----- | | sku | Major |

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