Allow multiple users (e.g., spouses or partners) to access the same Piere household under their own login. Currently, each person must create their own separate account and household. Many couples and families track shared finances together – being able to log in independently and view the same accounts, transactions, budgets, and net worth would make Piere significantly more useful for households where more than one person manages money. This could be implemented as an invite/share flow where the primary account holder grants access to a second user.