perf: enforce journey budgets and reference traces

tests/performance/budgets.test.ts

@@ -0,0 +1,41 @@
+import { describe, expect, it } from 'vitest';
+import { classifyArtifact, evaluateBudgetTotals, PERFORMANCE_BUDGETS } from '../../scripts/lib/bundle-budgets.mjs';
+
+describe('release budgets', () => {
+  it('pins every exact section 14 threshold', () => {
+    expect(PERFORMANCE_BUDGETS).toMatchObject({
+      initialHtmlCriticalCss: 100 * 1024,
+      initialApplicationJs: 120 * 1024,
+      heroPoster: 220 * 1024,
+      initialFonts: 120 * 1024,
+      firstLiveScene: 650 * 1024,
+      projectVideo: 2.5 * 1024 * 1024,
+      projectVideoDurationSeconds: 10,
+      projectVideoWidth: 1280,
+      projectVideoHeight: 720,
+      projectStill: 400 * 1024,
+      chart: 100 * 1024,
+      deferredProjectVisuals: 2.5 * 1024 * 1024,
+      highTierExtras: 750 * 1024,
+      deferredNonVideo: 3.5 * 1024 * 1024,
+      imageSceneConcurrency: 2,
+      videoConcurrency: 1,
+      mobileTextureDimension: 2048,
+      lowTierGpuEstimate: 96 * 1024 * 1024,
+      highTierGpuEstimate: 192 * 1024 * 1024,
+    });
+  });
+
+  it('classifies every artifact once and keeps the scene chunk deferred', () => {
+    expect(classifyArtifact('index.html', '<script src="/assets/index-a.js"></script>')).toBe('initial-html');
+    expect(classifyArtifact('assets/index-a.css', '')).toBe('critical-css');
+    expect(classifyArtifact('assets/index-a.js', 'import("./environment-b.js")')).toBe('initial-application-js');
+    expect(classifyArtifact('assets/environment-b.js', 'three scene')).toBe('first-live-scene');
+    expect(() => classifyArtifact('assets/mystery.bin', '')).toThrow(/unclassified/u);
+  });
+
+  it('fails exact byte boundaries and accepts equality', () => {
+    expect(evaluateBudgetTotals({ initialHtmlCriticalCss: 100 * 1024 }).violations).toEqual([]);
+    expect(evaluateBudgetTotals({ initialHtmlCriticalCss: 100 * 1024 + 1 }).violations).toContainEqual(expect.objectContaining({ budget: 'initialHtmlCriticalCss' }));
+  });
+});