OptionalEntityPopulated on success — the new entity's ID in MJ: Entities.
OptionalEntityPopulated on success — the MJ entity name (e.g. "Meetup Attendees").
OptionalErrorPopulated on failure.
OptionalPipelineStep-by-step pipeline trace from RuntimeSchemaManager.
OptionalSchemaSQL schema name (e.g. "__mj_UDT").
OptionalTablePhysical table name (e.g. "MeetupAttendees").
Outcome for a single table within a DatabaseDesignerResult batch. Maps 1-to-1 with SchemaDesignEntry and PipelineExecutionResult.