[Platform] Director Handoff / Leadership Transfer

Raised Sept 25. Co-op leadership turns over, and there's no clean way to hand the director role and all its access to a new person without an account-sharing workaround. Real risk: whoever holds the login effectively owns the co-op's data and Stripe connection. Scope: a formal director-transfer flow (outgoing director initiates or an org owner reassigns), moving admin access and Stripe Connect ownership cleanly to a new account, with an audit trail of the handoff.