Get savings-goal progress

What your assistant is told

Read savings-goal progress for the calling user. Omit goal_id to list ALL goals with their current vs target totals; pass a goal_id UUID to fetch just that one. Each goal returns its id, name, target and current amounts (minor units), currency, and optional target date. Use this to find a goal's id before log_savings_deposit, or to answer "how close am I?". Read-only.