The stable registry key of the operation (e.g. RecordProcess.GetRunStatus).
The operation's typed input payload.
Invocation options (the acting user and optional onProgress).
The provider to hand to the operation for data access.
OptionalfallbackUser: UserInfoUser to use when options.user is absent (typically the provider's CurrentUser).
The operation result.
Resolves a Remote Operation by key from the ClassFactory and executes it in-process via BaseRemotableOperation.ExecuteServer. Returns a structured failure (never throws) when the operation is unknown or no acting user is available.