perf: enforce journey budgets and reference traces

scripts/lib/bundle-budgets.d.mts

@@ -0,0 +1,5 @@
+export const PERFORMANCE_BUDGETS: Readonly<Record<string, number>>;
+export function classifyArtifact(path: string, source?: string): string;
+export function evaluateBudgetTotals(totals: Readonly<Record<string, number>>): {
+  violations: Array<{ budget: string; actual: number; threshold: number }>;
+};