Client plans — assign a pricing plan to a client

A client's billing is no longer a placeholder:

• Assign a plan. On a client → Plan, pick any of your active pricing plans (the ones linked to a service). The client gets an active plan with its price, cycle, and — for recurring plans — a renewal date.
• One active plan at a time. Assigning a new plan automatically retires the previous one, so the Plan tab always reflects what the client is currently on.
• Change or cancel. Swap a client to a different plan, or cancel the current one. Cancellations stay in the record as history.
• Payment stays manual. This tracks which plan a client is on; you still record each payment with mark-as-paid in Payments. No automatic recurring charge is created.