Added
- Budget: a new Plan tab for planned/estimated budgets, so a household can see whether its spending and savings targets are being met. Set a monthly savings goal (shown as a progress ring comparing planned savings against the month's income minus expenses, with a reached/short/negative status) and a monthly budget per expense category (shown as planned-vs-actual progress bars that turn amber near the limit and red when over budget, each with a plain-text "X left"/"X over budget" label so status never relies on colour alone). Budgets and the goal are set, edited, and removed from a modal; deleting is confirmation-gated. The Statistics tab draws a target marker on each category bar at its planned amount (month range), and the dashboard Budget widget shows savings-goal progress when a goal is set. (#468)