The local entries record type
The constraints type providing the inherited template via Inheritance
Subtracting keyof E from the inherited side before intersection is required because TypeScript intersection is
order-insensitive: without the subtraction the parent's contribution is retained alongside the child's narrowing,
leaving residue such as string & { readonly "0": string; readonly "1": Locales } on slots narrowed via
single-variant union narrowing (Form 1).
Composes the resource model from local entries and inherited template.
Locally-redeclared keys are taken from Prototype : the child slot replaces the inherited
contribution wholesale; non-overridden inherited keys flow through from Inheritance .
Mirrors at the type level the override semantics enforced by resource on the runtime side. The result is
merged into a single flat property list, so local and inherited entries read alike and both keep
the optional keys Relaxed assigns to entries admitting absence.