Get Active Prospecting Goal

Return the org's currently-active prospecting goal so the AI Zone intake can reflect the goal the next run will default to (instead of the generic 'Everything/Everyone' placeholder).

Active goal = the goal of the org's most recent run (latest non-null deal.goal_id), falling back to the most recently created non-archived goal, else null (fresh org → the UI shows the broad Everything/Everyone default). The UI pre-fills the intake fields only for user-specified goals (source user_intake/manual); for a derived_default it shows the broad default plus a label, since the run re-derives when intake is empty. When include_derived_default is true, derived_default additionally lets the UI show what an empty-intake run will actually use instead of the broad placeholder.