How does Pinia 3's typed stores eliminate Vuex boilerplate?

// stores/dashboard.ts
interface DashboardState {
  metrics: Record<string, number>
  alerts: string[]
}

export const useDashboard = defineStore('dashboard', () => {
  const metrics = ref<Record<string, number>({})
  const alerts = ref<string[]>([])
  
  const updateMetrics = (newMetrics: Record<string, number>) => {
    metrics.value = newMetrics  // Direct mutation + TS safety
  }
  
  return { metrics, alerts, updateMetrics }
}, { 
  // Full type inference
}) satisfies StoreDefinition<DashboardState>