Bulk Update Object Records

Apply the same values to every record in an explicit or filtered scope.

Registered before /{object_slug}/records/{record_id}: routes match by path shape, so "bulk" would otherwise bind to {record_id}. Needs objects:read as well as objects:write (a filtered scope echoes the ids that match caller-chosen predicates). Delegates to the Studio function, so the server-side filter resolution, the 500-row cursor, the per-row savepoints and the per-org records_core switch (404 while off) are identical.