BucketRef
BucketRef = {
id:number;key?:never;name?:never; } | {id?:never;key?:never;name:string; }
Selects a bucket by exactly one identifier — { id } numeric or { name }
(folder-scoped). Used by the ref-based file-op signatures on
BucketServiceModel (uploadFile, deleteFile, getReadUri,
getFiles, getFileMetaData). { name } triggers an internal
folder-scoped lookup so runtime overrides apply; { id } skips the lookup.
Narrower than the generic ResourceRef — buckets don't have a public GUID key
on their operational routes, so { key } is intentionally not part of this union.