feat: coordinate adaptive audio intent

tests/unit/use-audio-intent.test.ts

@@ -0,0 +1,66 @@
+import { defineComponent, h, readonly, shallowRef } from 'vue';
+import { mount } from '@vue/test-utils';
+import { describe, expect, it, vi } from 'vitest';
+import { resolveChapterIntent } from '@/audio/journey-music-state';
+import {
+  useAudioIntent,
+  type AudioIntentBinding,
+} from '@/composables/useAudioIntent';
+import type { JourneySectionsBinding } from '@/composables/useJourneySections';
+import type { SectionId } from '@/content/types';
+import type { NavigationState } from '@/journey/navigation-controller';
+import type { JourneySnapshot } from '@/journey/types';
+
+const sectionIds = [
+  'start', 'profile', 'experience', 'infrastructure',
+  'selected-builds', 'additional-work', 'toolkit', 'contact',
+] as const satisfies readonly SectionId[];
+
+describe('useAudioIntent', () => {
+  it('seeds the first measured deep-link section before audio activation', () => {
+    const snapshot = shallowRef<JourneySnapshot>({
+      scrollY: 7_200,
+      routeProgress: 1,
+      direction: 0,
+      acceleration: 0,
+      driveSpeed: 0.18,
+      activeSectionId: 'contact',
+      chapter: 'destination',
+      sign: null,
+      arrived: true,
+      sectionActivation: {
+        layoutRevision: 4,
+        activeHeadingOffsetVh: -0.2,
+        nextHeadingOffsetVh: null,
+      },
+    });
+    const navigation = shallowRef<NavigationState>({
+      epoch: 1,
+      source: 'initial',
+      phase: 'settled',
+      destinationId: 'contact',
+      signDestinationId: null,
+    });
+    let frame: ((now: number, value: JourneySnapshot) => boolean) | null = null;
+    const journey: JourneySectionsBinding = {
+      snapshot: readonly(snapshot),
+      requestFrame: vi.fn(),
+      subscribeFrame(listener) {
+        frame = listener;
+        return () => { frame = null; };
+      },
+    };
+    let binding: AudioIntentBinding | null = null;
+    const wrapper = mount(defineComponent({
+      setup() {
+        binding = useAudioIntent({ canonicalIds: sectionIds, journey, navigation });
+        return () => h('div');
+      },
+    }));
+
+    expect(frame).not.toBeNull();
+    frame!(16, snapshot.value);
+    expect(binding!.chapter.value).toEqual(resolveChapterIntent('contact'));
+    wrapper.unmount();
+  });
+});