Narrows DeepPartial<T> down to exactly the keys TOwnership (a
FieldOwnership<T> value) permits, mirroring its shape one-for-one. A
processor/optimistic callback declared against writes: {user: {email: true}} cannot type-check while returning {post: ...}, or even
{user: {name: ...}} -- a sibling field it doesn't own. This narrows the
legal shape at compile time only; resolveOperationPatch still enforces
the same boundary at runtime regardless, since a processor's actual
return value is never statically provable to match its declared type.
Narrows
DeepPartial<T>down to exactly the keysTOwnership(aFieldOwnership<T>value) permits, mirroring its shape one-for-one. Aprocessor/optimisticcallback declared againstwrites: {user: {email: true}}cannot type-check while returning{post: ...}, or even{user: {name: ...}}-- a sibling field it doesn't own. This narrows the legal shape at compile time only;resolveOperationPatchstill enforces the same boundary at runtime regardless, since a processor's actual return value is never statically provable to match its declared type.