diff --git a/scripts/verify-artifacts.mjs b/scripts/verify-artifacts.mjs
index 535801c..5c84a21 100644
--- a/scripts/verify-artifacts.mjs
+++ b/scripts/verify-artifacts.mjs
@@ -15,6 +15,8 @@ const canonicalSectionIds = [
 ];
 const prohibitedSurfaces = [
   /__PORTFOLIO_INPUTS__/iu,
+  /__PORTFOLIO_(?:TEST|INSTRUMENTATION)__/iu,
+  /__portfolio(?:Journey)?Instrumentation/iu,
   /(?:evidenceId|sourcePath|sourceFingerprint|approvalOwner|privacyClassification|denylist|originalFilename)/iu,
   /sourceMappingURL/iu,
 ];
diff --git a/src/components/SceneCanvas.vue b/src/components/SceneCanvas.vue
index 83bc681..db5133f 100644
--- a/src/components/SceneCanvas.vue
+++ b/src/components/SceneCanvas.vue
@@ -21,6 +21,7 @@ const journey = toRef(props, 'journey');
 const policy = toRef(props, 'policy');
 const quality = toRef(props, 'quality');
 const scene = useSceneController({ canvas, journey, policy, quality });
+const sceneState = computed(() => scene.state.value);
 const showCanvas = computed(() => (
   clientReady.value
   && policy.value.allowSceneRequest
@@ -34,7 +35,7 @@ onMounted(() => { clientReady.value = true; });
 
 <template>
   <p id="journey-scene-description" class="visually-hidden">{{ sceneDescription }}</p>
-  <div class="journey-world" aria-hidden="true" :data-scene-state="scene.state">
+  <div class="journey-world" aria-hidden="true" :data-scene-state="sceneState">
     <img class="journey-poster" alt="" width="1600" height="900">
     <canvas v-if="showCanvas" ref="canvas" class="journey-canvas" aria-hidden="true" />
   </div>
diff --git a/src/composables/useMotionPreferences.ts b/src/composables/useMotionPreferences.ts
index c367cf2..b3202d6 100644
--- a/src/composables/useMotionPreferences.ts
+++ b/src/composables/useMotionPreferences.ts
@@ -51,6 +51,7 @@ export function useMotionPreferences(): MotionPreferences {
   let reducedQuery: MediaQueryList | undefined;
   let coarseQuery: MediaQueryList | undefined;
   let connection: NetworkInformationLike | undefined;
+  let requiresExplicitEnable = false;
   let teardown = (): void => {};
 
   const viewportWidth = (): number => window.visualViewport?.width ?? window.innerWidth;
@@ -60,7 +61,7 @@ export function useMotionPreferences(): MotionPreferences {
     policy.value = resolveMotionPolicy({
       systemReduce: systemReduce.value,
       savedPause: paused.value,
-      savedStatic: maximumQuality.value === 'static',
+      savedStatic: maximumQuality.value === 'static' || requiresExplicitEnable,
       dataSaver: dataSaver.value,
       width: viewportWidth(),
       coarsePointer,
@@ -79,6 +80,7 @@ export function useMotionPreferences(): MotionPreferences {
   };
 
   const setPaused = (value: boolean): void => {
+    if (!value) requiresExplicitEnable = false;
     paused.value = value;
     persist(MOTION_PREFERENCE_KEYS.pause, String(value));
     if (typeof window !== 'undefined') {
@@ -87,6 +89,7 @@ export function useMotionPreferences(): MotionPreferences {
   };
 
   const setMaximumQuality = (value: QualityTier): void => {
+    if (value !== 'static') requiresExplicitEnable = false;
     maximumQuality.value = value;
     persist(MOTION_PREFERENCE_KEYS.maximumQuality, value);
     if (typeof window !== 'undefined') {
@@ -112,7 +115,9 @@ export function useMotionPreferences(): MotionPreferences {
       connection = (window.navigator as Navigator & { connection?: NetworkInformationLike }).connection;
 
       const updateReduced = (): void => {
-        systemReduce.value = reducedQuery?.matches ?? true;
+        const nextSystemReduce = reducedQuery?.matches ?? true;
+        if (systemReduce.value && !nextSystemReduce) requiresExplicitEnable = true;
+        systemReduce.value = nextSystemReduce;
         updatePolicy();
       };
       const updateCoarse = (): void => updatePolicy();
diff --git a/src/composables/useSceneController.ts b/src/composables/useSceneController.ts
index 4399f72..b64a54f 100644
--- a/src/composables/useSceneController.ts
+++ b/src/composables/useSceneController.ts
@@ -62,7 +62,7 @@ export function useSceneController(sources: SceneControllerSources): SceneContro
     const allowed = sources.policy.value.allowSceneRequest && sources.quality.value !== 'static';
     const canvas = sources.canvas.value;
     if (!allowed || canvas === null) {
-      disposeActive(allowed ? 'idle' : 'static');
+      disposeActive(allowed ? (error.value ? 'failed' : 'idle') : 'static');
       return;
     }
 
diff --git a/tests/browser/README.md b/tests/browser/README.md
new file mode 100644
index 0000000..33824c2
--- /dev/null
+++ b/tests/browser/README.md
@@ -0,0 +1,35 @@
+# Browser characterization tests
+
+These Playwright tests lock the observable portfolio behavior at the browser
+boundary. They exercise the built `dist/` output through the local preview
+server rather than replacing Vue, Three.js, WebGL, or Web Audio with production
+test hooks.
+
+## Run
+
+Build the preview artifacts, then run the whole browser suite:
+
+```bash
+npm run build:preview
+npm run test:browser
+```
+
+Run only the Phase 2 journey gate:
+
+```bash
+npm run test:browser -- tests/browser/journey-integration.spec.ts tests/browser/reduced-motion.spec.ts tests/browser/static-fallback.spec.ts tests/browser/bfcache-lifecycle.spec.ts
+```
+
+## Add a case
+
+1. Name the concrete regression the case catches.
+2. Use literal inputs and expected browser-visible results.
+3. Install `scene-instrumentation.ts` before navigation when resource counts or
+   platform calls are the observable boundary.
+4. Keep failure injection in `page.addInitScript()` or Playwright routing; do
+   not add a test API to the application bundle.
+5. Run the new case against both configured Chromium profiles, then run the
+   full suite.
+
+Never copy credentials, private project identifiers, or private URLs into a
+fixture. Use clearly fake values when a credential-shaped input is required.
diff --git a/tests/browser/bfcache-lifecycle.spec.ts b/tests/browser/bfcache-lifecycle.spec.ts
new file mode 100644
index 0000000..0a05845
--- /dev/null
+++ b/tests/browser/bfcache-lifecycle.spec.ts
@@ -0,0 +1,57 @@
+import { expect, test } from '../helpers/serve-dist';
+import {
+  dispatchPersistedPageTransition,
+  installSceneInstrumentation,
+  readSceneInstrumentation,
+} from '../helpers/scene-instrumentation';
+
+test.beforeEach(async ({ page }) => installSceneInstrumentation(page));
+
+test('synthetic persisted freeze and restore keeps at most one canvas, RAF loop, and audio context', async ({
+  page,
+  distUrl,
+}) => {
+  await page.goto(distUrl, { waitUntil: 'domcontentloaded' });
+  await expect(page.locator('.journey-world')).toHaveAttribute('data-scene-state', 'running');
+  await page.getByRole('button', { name: 'START THE DRIVE' }).click();
+  await expect(page.getByRole('button', { name: 'Mute sound' })).toBeVisible();
+
+  for (let cycle = 0; cycle < 3; cycle += 1) {
+    await dispatchPersistedPageTransition(page, 'pagehide');
+    await expect.poll(async () => (await readSceneInstrumentation(page)).activeAnimationFrames).toBe(0);
+    await dispatchPersistedPageTransition(page, 'pageshow');
+    await expect(page.locator('.journey-world')).toHaveAttribute('data-scene-state', 'running');
+    await expect.poll(async () => (await readSceneInstrumentation(page)).activeAnimationFrames).toBeLessThanOrEqual(1);
+  }
+
+  const state = await readSceneInstrumentation(page);
+  expect(state.maximumCanvasCount).toBe(1);
+  expect(await page.locator('.journey-canvas').count()).toBe(1);
+  expect(state.audioContextsConstructed).toBe(1);
+  expect(state.liveAudioContexts).toBeLessThanOrEqual(1);
+});
+
+test('persisted lifecycle events preserve paused and Static states without duplicate resources', async ({
+  page,
+  distUrl,
+}) => {
+  await page.goto(distUrl, { waitUntil: 'domcontentloaded' });
+  await expect(page.locator('.journey-world')).toHaveAttribute('data-scene-state', 'running');
+
+  await page.getByRole('button', { name: 'Pause motion' }).click();
+  await dispatchPersistedPageTransition(page, 'pagehide');
+  await dispatchPersistedPageTransition(page, 'pageshow');
+  await expect(page.locator('.journey-canvas')).toHaveCount(0);
+  await expect(page.getByRole('button', { name: 'Resume motion' })).toBeVisible();
+
+  await page.getByLabel('Quality control').selectOption('static');
+  await dispatchPersistedPageTransition(page, 'pagehide');
+  await dispatchPersistedPageTransition(page, 'pageshow');
+  await expect(page.locator('.journey-canvas')).toHaveCount(0);
+  await expect(page.getByRole('button', { name: 'Enable motion' })).toBeVisible();
+
+  const state = await readSceneInstrumentation(page);
+  expect(state.maximumCanvasCount).toBeLessThanOrEqual(1);
+  await expect.poll(async () => (await readSceneInstrumentation(page)).activeAnimationFrames).toBe(0);
+  expect(state.liveAudioContexts).toBe(0);
+});
diff --git a/tests/browser/journey-integration.spec.ts b/tests/browser/journey-integration.spec.ts
new file mode 100644
index 0000000..4a8f037
--- /dev/null
+++ b/tests/browser/journey-integration.spec.ts
@@ -0,0 +1,101 @@
+import { expect, test } from '../helpers/serve-dist';
+import {
+  installSceneInstrumentation,
+  readSceneInstrumentation,
+  waitForOneAnimationFrame,
+} from '../helpers/scene-instrumentation';
+
+const sections = [
+  { id: 'start', label: 'Start' },
+  { id: 'profile', label: 'Profile' },
+  { id: 'experience', label: 'Experience' },
+  { id: 'infrastructure', label: 'Infrastructure' },
+  { id: 'selected-builds', label: 'Selected builds' },
+  { id: 'additional-work', label: 'Additional work' },
+  { id: 'toolkit', label: 'Toolkit' },
+  { id: 'contact', label: 'Contact' },
+] as const;
+
+test.beforeEach(async ({ page }) => installSceneInstrumentation(page));
+
+test('keeps navigation, HUD, progress, chapter, and arrival on the same next-frame section snapshot', async ({
+  page,
+  distUrl,
+}) => {
+  await page.goto(distUrl, { waitUntil: 'domcontentloaded' });
+  await expect(page.locator('.journey-world')).toHaveAttribute('data-scene-state', /running|failed|static/u);
+  const chapterColors: string[] = [];
+
+  for (const section of sections) {
+    await page.evaluate((id) => {
+      const heading = document.getElementById(`${id}-heading`);
+      if (!(heading instanceof HTMLElement)) throw new Error(`Missing heading: ${id}`);
+      const top = heading.getBoundingClientRect().top + window.scrollY;
+      const viewportHeight = window.visualViewport?.height ?? window.innerHeight;
+      const destination = id === 'contact'
+        ? document.documentElement.scrollHeight
+        : Math.max(0, top - viewportHeight * 0.35 + 1);
+      window.scrollTo({ top: destination, behavior: 'instant' });
+    }, section.id);
+    await waitForOneAnimationFrame(page);
+
+    await expect(page.locator(`nav a[href="#${section.id}"]`)).toHaveAttribute('aria-current', 'page');
+    await expect(page.locator('.journey-hud__section')).toHaveText(section.label);
+    const routeText = await page.locator('.journey-hud__route').textContent();
+    expect(routeText).toMatch(/^ROUTE (?:100|[0-9]{1,2})%$/u);
+    if (section.id === 'contact') {
+      await expect(page.locator('.journey-hud__arrival')).toHaveText('ARRIVED');
+      await expect(page.locator('.journey-hud__route')).toHaveText('ROUTE 100%');
+    } else {
+      await expect(page.locator('.journey-hud__arrival')).toHaveCount(0);
+    }
+    // The section snapshot is emitted in the scroll RAF above; the scene's
+    // already-running loop must consume it no later than its next RAF.
+    await waitForOneAnimationFrame(page);
+    const clearColors = (await readSceneInstrumentation(page)).clearColors.filter((color) => color !== '#000000');
+    const latestChapterColor = clearColors.at(-1);
+    if (latestChapterColor === undefined) throw new Error(`Missing rendered chapter color for ${section.id}`);
+    chapterColors.push(latestChapterColor);
+  }
+
+  const instrumentation = await readSceneInstrumentation(page);
+  expect(instrumentation.maximumCanvasCount).toBeLessThanOrEqual(1);
+  const expectedChapterColors = (page.viewportSize()?.width ?? 0) < 768
+    ? [
+        '#040713', '#040713', '#060918', '#080b1d',
+        '#0d1025', '#0d1025', '#18152c', '#2b2035',
+      ]
+    : [
+        '#000102', '#000102', '#000102', '#010103',
+        '#010105', '#010105', '#020206', '#060409',
+      ];
+  expect(chapterColors).toEqual(expectedChapterColors);
+});
+
+test('draws only the independently eligible next roadside sign during passive forward travel', async ({
+  page,
+  distUrl,
+}) => {
+  await page.goto(distUrl, { waitUntil: 'domcontentloaded' });
+  await expect(page.locator('.journey-world')).toHaveAttribute('data-scene-state', 'running');
+
+  const oracle = await page.evaluate(() => {
+    const profile = document.getElementById('profile-heading');
+    if (!(profile instanceof HTMLElement)) throw new Error('Missing profile heading');
+    const viewportHeight = window.visualViewport?.height ?? window.innerHeight;
+    const headingTop = profile.getBoundingClientRect().top + window.scrollY;
+    const destination = Math.max(1, headingTop - viewportHeight * (0.35 + 0.8));
+    return { destination, viewportHeight, expectedLabel: '01 / PROFILE' };
+  });
+  await page.evaluate(() => window.dispatchEvent(new WheelEvent('wheel', { deltaY: 1 })));
+  for (let y = 1; y < oracle.destination; y += oracle.viewportHeight * 0.5) {
+    await page.evaluate((nextY) => window.scrollTo(0, nextY), y);
+    await waitForOneAnimationFrame(page);
+  }
+  await page.evaluate((destination) => window.scrollTo(0, destination), oracle.destination);
+  await waitForOneAnimationFrame(page);
+
+  await expect.poll(async () => (await readSceneInstrumentation(page)).routeLabelsDrawn).toContain(oracle.expectedLabel);
+  const labels = (await readSceneInstrumentation(page)).routeLabelsDrawn;
+  expect([...new Set(labels)]).toEqual([oracle.expectedLabel]);
+});
diff --git a/tests/browser/reduced-motion.spec.ts b/tests/browser/reduced-motion.spec.ts
new file mode 100644
index 0000000..6c87b0e
--- /dev/null
+++ b/tests/browser/reduced-motion.spec.ts
@@ -0,0 +1,40 @@
+import { expect, test } from '../helpers/serve-dist';
+import {
+  environmentChunkPattern,
+  installSceneInstrumentation,
+  readSceneInstrumentation,
+} from '../helpers/scene-instrumentation';
+
+test.beforeEach(async ({ page }) => installSceneInstrumentation(page));
+
+test('boots reduced motion without requesting the live scene or automatic media', async ({ page, distUrl }) => {
+  const requests: string[] = [];
+  page.on('request', (request) => requests.push(request.url()));
+  await page.emulateMedia({ reducedMotion: 'reduce' });
+  await page.goto(distUrl, { waitUntil: 'domcontentloaded' });
+
+  await expect(page.locator('.journey-poster')).toHaveCount(1);
+  await expect(page.locator('.journey-canvas')).toHaveCount(0);
+  await expect(page.locator('.journey-hud')).toBeVisible();
+  await expect(page.locator('nav[aria-label="Portfolio sections"]')).toBeVisible();
+  await expect(page.locator('#contact a[href^="mailto:"]')).toBeVisible();
+  await expect(page.getByRole('status')).toContainText('reduced motion requested');
+  expect(requests.some((url) => environmentChunkPattern.test(url))).toBe(false);
+  await expect(page.locator('video[src], video source[src]')).toHaveCount(0);
+  expect((await readSceneInstrumentation(page)).routeLabelsDrawn).toEqual([]);
+});
+
+test('requires explicit Enable motion after the system stops requesting reduction', async ({ page, distUrl }) => {
+  const requests: string[] = [];
+  page.on('request', (request) => requests.push(request.url()));
+  await page.emulateMedia({ reducedMotion: 'reduce' });
+  await page.goto(distUrl, { waitUntil: 'domcontentloaded' });
+
+  await page.emulateMedia({ reducedMotion: 'no-preference' });
+
+  await expect(page.getByRole('button', { name: 'Enable motion' })).toBeVisible();
+  expect(requests.some((url) => environmentChunkPattern.test(url))).toBe(false);
+
+  await page.getByRole('button', { name: 'Enable motion' }).click();
+  await expect.poll(() => requests.some((url) => environmentChunkPattern.test(url))).toBe(true);
+});
diff --git a/tests/browser/static-fallback.spec.ts b/tests/browser/static-fallback.spec.ts
new file mode 100644
index 0000000..eb3ddc9
--- /dev/null
+++ b/tests/browser/static-fallback.spec.ts
@@ -0,0 +1,68 @@
+import { expect, test } from '../helpers/serve-dist';
+import {
+  environmentChunkPattern,
+  installSceneInstrumentation,
+  readSceneInstrumentation,
+} from '../helpers/scene-instrumentation';
+
+test.beforeEach(async ({ page }) => installSceneInstrumentation(page));
+
+test('falls back to one poster and no scene loop when the deferred scene chunk is unavailable', async ({
+  page,
+  distUrl,
+}) => {
+  const pageErrors: string[] = [];
+  page.on('pageerror', (error) => pageErrors.push(error.message));
+  await page.route(environmentChunkPattern, (route) => route.abort('failed'));
+  await page.goto(distUrl, { waitUntil: 'domcontentloaded' });
+
+  await expect(page.locator('.journey-world')).toHaveAttribute('data-scene-state', 'failed');
+  await expect(page.locator('.journey-poster')).toHaveCount(1);
+  await expect(page.locator('.journey-canvas')).toHaveCount(0);
+  await expect(page.locator('main > section')).toHaveCount(8);
+  await expect(page.locator('nav a[href="#contact"]')).toBeVisible();
+  await expect(page.locator('#contact a[href^="mailto:"]')).toBeVisible();
+  await expect.poll(async () => (await readSceneInstrumentation(page)).activeAnimationFrames).toBe(0);
+  expect((await readSceneInstrumentation(page)).unhandledRejections).toEqual([]);
+  expect(pageErrors).toEqual([]);
+});
+
+test('contains a WebGL initialization failure without hiding the portfolio', async ({ page, distUrl }) => {
+  const pageErrors: string[] = [];
+  page.on('pageerror', (error) => pageErrors.push(error.message));
+  await page.addInitScript(() => {
+    const nativeGetContext = HTMLCanvasElement.prototype.getContext;
+    Object.defineProperty(HTMLCanvasElement.prototype, 'getContext', {
+      configurable: true,
+      value(this: HTMLCanvasElement, contextId: string, options?: unknown): RenderingContext | null {
+        if (contextId === 'webgl' || contextId === 'webgl2' || contextId === 'experimental-webgl') return null;
+        return Reflect.apply(nativeGetContext, this, [contextId, options]) as RenderingContext | null;
+      },
+    });
+  });
+  await page.goto(distUrl, { waitUntil: 'domcontentloaded' });
+
+  await expect(page.locator('.journey-world')).toHaveAttribute('data-scene-state', 'failed');
+  await expect(page.locator('.journey-poster')).toHaveCount(1);
+  await expect(page.locator('.journey-canvas')).toHaveCount(0);
+  await expect(page.locator('#portfolio-content')).toBeVisible();
+  await expect(page.locator('#contact a[href^="mailto:"]')).toBeVisible();
+  await expect.poll(async () => (await readSceneInstrumentation(page)).activeAnimationFrames).toBe(0);
+  expect((await readSceneInstrumentation(page)).unhandledRejections).toEqual([]);
+  expect(pageErrors).toEqual([]);
+});
+
+test('allows an explicit Static visitor to re-enable motion when the system permits it', async ({ page, distUrl }) => {
+  const requests: string[] = [];
+  page.on('request', (request) => requests.push(request.url()));
+  await page.goto(distUrl, { waitUntil: 'domcontentloaded' });
+  await page.getByLabel('Quality control').selectOption('static');
+
+  await expect(page.getByRole('button', { name: 'Enable motion' })).toBeVisible();
+  await expect(page.locator('.journey-canvas')).toHaveCount(0);
+  await page.getByRole('button', { name: 'Enable motion' }).click();
+
+  await expect(page.locator('.journey-world')).toHaveAttribute('data-scene-state', 'running');
+  await expect(page.locator('.journey-canvas')).toHaveCount(1);
+  expect(requests.some((url) => environmentChunkPattern.test(url))).toBe(true);
+});
diff --git a/tests/helpers/scene-instrumentation.ts b/tests/helpers/scene-instrumentation.ts
new file mode 100644
index 0000000..8ef9f87
--- /dev/null
+++ b/tests/helpers/scene-instrumentation.ts
@@ -0,0 +1,160 @@
+import type { Page } from '@playwright/test';
+
+export const environmentChunkPattern = /\/assets\/environment-[^/]+\.js(?:[?#].*)?$/u;
+
+export interface SceneInstrumentationSnapshot {
+  activeAnimationFrames: number;
+  maximumCanvasCount: number;
+  audioContextsConstructed: number;
+  liveAudioContexts: number;
+  routeLabelsDrawn: string[];
+  clearColors: string[];
+  unhandledRejections: string[];
+}
+
+type InstrumentedWindow = Window & {
+  __portfolioJourneyInstrumentation?: SceneInstrumentationSnapshot & {
+    animationFrameIds: Set<number>;
+    audioContexts: AudioContext[];
+  };
+};
+
+/**
+ * Installs browser-owned observers before application code runs. The helper
+ * patches platform boundaries only; no test API is compiled into the site.
+ */
+export async function installSceneInstrumentation(page: Page): Promise<void> {
+  await page.addInitScript(() => {
+    const instrumentedWindow = window as InstrumentedWindow;
+    const state: NonNullable<InstrumentedWindow['__portfolioJourneyInstrumentation']> = {
+      activeAnimationFrames: 0,
+      maximumCanvasCount: 0,
+      audioContextsConstructed: 0,
+      liveAudioContexts: 0,
+      routeLabelsDrawn: [],
+      clearColors: [],
+      unhandledRejections: [],
+      animationFrameIds: new Set<number>(),
+      audioContexts: [],
+    };
+    Object.defineProperty(instrumentedWindow, '__portfolioJourneyInstrumentation', {
+      configurable: false,
+      enumerable: false,
+      value: state,
+      writable: false,
+    });
+
+    const nativeRequestAnimationFrame = window.requestAnimationFrame.bind(window);
+    const nativeCancelAnimationFrame = window.cancelAnimationFrame.bind(window);
+    window.requestAnimationFrame = (callback: FrameRequestCallback): number => {
+      let id = 0;
+      id = nativeRequestAnimationFrame((now) => {
+        state.animationFrameIds.delete(id);
+        state.activeAnimationFrames = state.animationFrameIds.size;
+        callback(now);
+      });
+      state.animationFrameIds.add(id);
+      state.activeAnimationFrames = state.animationFrameIds.size;
+      return id;
+    };
+    window.cancelAnimationFrame = (id: number): void => {
+      state.animationFrameIds.delete(id);
+      state.activeAnimationFrames = state.animationFrameIds.size;
+      nativeCancelAnimationFrame(id);
+    };
+
+    const updateCanvasCount = (): void => {
+      state.maximumCanvasCount = Math.max(
+        state.maximumCanvasCount,
+        document.querySelectorAll('.journey-canvas').length,
+      );
+    };
+    document.addEventListener('DOMContentLoaded', () => {
+      updateCanvasCount();
+      new MutationObserver(updateCanvasCount).observe(document.documentElement, {
+        childList: true,
+        subtree: true,
+      });
+    }, { once: true });
+
+    const nativeFillText = CanvasRenderingContext2D.prototype.fillText;
+    CanvasRenderingContext2D.prototype.fillText = function fillText(
+      text: string,
+      x: number,
+      y: number,
+      maxWidth?: number,
+    ): void {
+      if (/^0[0-7] \/ /u.test(text)) state.routeLabelsDrawn.push(text);
+      if (maxWidth === undefined) nativeFillText.call(this, text, x, y);
+      else nativeFillText.call(this, text, x, y, maxWidth);
+    };
+
+    const colorChannel = (value: number): string => Math.round(value * 255)
+      .toString(16)
+      .padStart(2, '0');
+    const patchClearColor = (prototype: WebGLRenderingContext | WebGL2RenderingContext): void => {
+      const nativeClearColor = prototype.clearColor;
+      prototype.clearColor = function clearColor(red, green, blue, alpha): void {
+        state.clearColors.push(`#${colorChannel(red)}${colorChannel(green)}${colorChannel(blue)}`);
+        nativeClearColor.call(this, red, green, blue, alpha);
+      };
+    };
+    if (typeof WebGLRenderingContext !== 'undefined') patchClearColor(WebGLRenderingContext.prototype);
+    if (typeof WebGL2RenderingContext !== 'undefined') patchClearColor(WebGL2RenderingContext.prototype);
+
+    const NativeAudioContext = window.AudioContext;
+    if (NativeAudioContext) {
+      class InstrumentedAudioContext extends NativeAudioContext {
+        constructor(options?: AudioContextOptions) {
+          super(options);
+          state.audioContextsConstructed += 1;
+          state.audioContexts.push(this);
+          state.liveAudioContexts = state.audioContexts.filter((context) => context.state !== 'closed').length;
+          this.addEventListener('statechange', () => {
+            state.liveAudioContexts = state.audioContexts.filter((context) => context.state !== 'closed').length;
+          });
+        }
+      }
+      Object.defineProperty(window, 'AudioContext', {
+        configurable: true,
+        value: InstrumentedAudioContext,
+      });
+    }
+
+    window.addEventListener('unhandledrejection', (event) => {
+      const reason = event.reason;
+      state.unhandledRejections.push(reason instanceof Error ? reason.message : String(reason));
+    });
+  });
+}
+
+export async function readSceneInstrumentation(page: Page): Promise<SceneInstrumentationSnapshot> {
+  return page.evaluate(() => {
+    const state = (window as InstrumentedWindow).__portfolioJourneyInstrumentation;
+    if (!state) throw new Error('Scene instrumentation was not installed before navigation.');
+    return {
+      activeAnimationFrames: state.animationFrameIds.size,
+      maximumCanvasCount: state.maximumCanvasCount,
+      audioContextsConstructed: state.audioContextsConstructed,
+      liveAudioContexts: state.audioContexts.filter((context) => context.state !== 'closed').length,
+      routeLabelsDrawn: [...state.routeLabelsDrawn],
+      clearColors: [...state.clearColors],
+      unhandledRejections: [...state.unhandledRejections],
+    };
+  });
+}
+
+export async function waitForOneAnimationFrame(page: Page): Promise<void> {
+  await page.evaluate(() => new Promise<void>((resolve) => {
+    window.requestAnimationFrame(() => queueMicrotask(resolve));
+  }));
+}
+
+export async function dispatchPersistedPageTransition(
+  page: Page,
+  type: 'pagehide' | 'pageshow',
+): Promise<void> {
+  await page.evaluate((eventType) => {
+    window.dispatchEvent(new PageTransitionEvent(eventType, { persisted: true }));
+  }, type);
+}
diff --git a/tests/unit/motion-policy.test.ts b/tests/unit/motion-policy.test.ts
index e6cd3e3..4e0dbca 100644
--- a/tests/unit/motion-policy.test.ts
+++ b/tests/unit/motion-policy.test.ts
@@ -200,7 +200,7 @@ describe('useMotionPreferences', () => {
     connection.saveData = true;
     connection.dispatchEvent(new Event('change'));
     await nextTick();
-    expect(wrapper.vm.policy).toMatchObject({ reason: 'data-saver', allowSceneRequest: false });
+    expect(wrapper.vm.policy).toMatchObject({ reason: 'saved-static', allowSceneRequest: false });
 
     connection.saveData = false;
     connection.dispatchEvent(new Event('change'));
@@ -209,6 +209,10 @@ describe('useMotionPreferences', () => {
     coarseQuery.dispatchEvent(new Event('change'));
     window.dispatchEvent(new Event('resize'));
     await nextTick();
+    expect(wrapper.vm.policy).toMatchObject({ reason: 'saved-static', maximumTier: 'static' });
+
+    wrapper.vm.setMaximumQuality('high');
+    await nextTick();
     expect(wrapper.vm.policy).toMatchObject({ reason: 'full', maximumTier: 'low' });
 
     wrapper.unmount();