Performance budgets in tests (usePerformanceBudget)

Declares named time budgets (in milliseconds) and lets tests start/stop labeled trackers around code to measure and (optionally) enforce them. Demonstrated in performance-budget-demo.test.ts.

const budgets = {quickOp: 100, heavyOp: 5};

const {usePerformanceBudget} = useNodeBoot(EmptyApp, ({useConfig, usePerformanceBudget}) => {
    useConfig({app: {port: 35005}});
    usePerformanceBudget({budgets, failOnExceeded: false}); // true fails the test on overrun instead of warning
});