The Statement schema and its related spec fragments live in the crud domain
(repo/domains/crud/specs/global/schemas.js, resources/statements/*), but
they're not really crud-specific: WikibaseLexeme's fragment (T433337: 👓 Create the WikibaseLexeme OpenAPI specification fragment) reuses
#/components/schemas/Statement via the served openapi.json, and any future
domain or extension documenting statements will need it too.

We already have a statements domain (repo/domains/statements, extracted in
T430944: 🦦 Move needed statement models into a statements domain) holding the shared statement read models. Let's consider moving the
statement spec fragments there as well, so the spec ownership matches the code
ownership and crud doesn't own a schema that's effectively cross-domain.