fix: polish pass for traffic, nav, icons, contact email reveal and dashcam robustness

tests/unit/SceneCanvas.test.ts

@@ -187,6 +187,35 @@ describe("SceneCanvas", () => {
     wrapper.unmount();
   });
 
+  it("writes html[data-dawn] without the scene only when the step changes", async () => {
+    const wrapper = mount(SceneCanvas, {
+      props: {
+        journey: journey(),
+        policy: policy({ allowSceneRequest: false, maximumTier: "static", reason: "system-reduce" }),
+        quality: "static",
+        sceneDescription: "A decorative night road behind the portfolio content.",
+      },
+    });
+    await flushPromises();
+    expect(document.documentElement.dataset.dawn).toBe("night");
+    const writes: string[] = [];
+    const observer = new MutationObserver((records) => {
+      for (const record of records) if (record.attributeName === "data-dawn") writes.push(document.documentElement.dataset.dawn ?? "");
+    });
+    observer.observe(document.documentElement, { attributes: true, attributeFilter: ["data-dawn"] });
+    // A scroll replaces the snapshot every frame; the step does not change.
+    for (let frame = 1; frame <= 6; frame++) {
+      await wrapper.setProps({ journey: journey({ scrollY: frame * 40, routeProgress: 0.42 + frame / 100 }) });
+      await flushPromises();
+    }
+    await wrapper.setProps({ journey: journey({ scrollY: 9000, routeProgress: 1, arrived: true }) });
+    await flushPromises();
+    observer.disconnect();
+    expect(writes).toEqual(["day"]);
+    wrapper.unmount();
+    expect(document.documentElement.dataset.dawn).toBeUndefined();
+  });
+
   it("aborts and removes the canvas on a Static transition", async () => {
     const wrapper = mount(SceneCanvas, {
       props: {