"Personal" Spaces and User-linked Holders

Right now Spaces and Holders are fairly independent, just modeling abstractions. If people start gravitating toward using accurate numbers, it could get tedious updating your state across multiple spaces you’re a member of (e.g., household space and extended family space).

A personal space has exactly one holder: you. And whenever you get added to a space, there’s an option to automatically bring in and link your holdings into that space.