Family tab — exposes the parent / child structure that the parallel primitive in Durable's runtime uses to fan a workflow out across multiple WorkflowExecution rows.

Layout:

• Parent card — when viewing a child, surfaces the root execution with its status + the step the current child handled.
• Children list — every direct + sibling child in the family, grouped by status, each with the parallel step name it ran, the child's own status pill, duration if recorded, and a deeplink.

Hidden entirely when the family has neither parent nor children — most workflows are flat, and the tab strip stays clean for them.