feat(radio): render stations and clusters on Navara

Preserve native clustering, selection and direct-action playback through renderer ports. Record both-engine dev/preview, legacy, contract, shell and build evidence with remaining W2 limits.

scripts/fixtures/w2/radio.mjs

@@ -0,0 +1,38 @@
+// Shared 750-station directory for legacy and both-engine radio QA.
+const tags = [
+  'news',
+  'talk',
+  'weather,emergency',
+  'public safety,scanner',
+  'aviation,atc',
+  'marine,maritime',
+  'traffic,transit',
+  'music,jazz',
+  'music,rock',
+  'community',
+];
+export const stations = Array.from({ length: 750 }, (_, index) => {
+  const row = Math.floor(index / 30);
+  const column = index % 30;
+  return {
+    id: `00000000-0000-4000-8000-${index.toString(16).padStart(12, '0')}`,
+    name:
+      index === 360
+        ? '100.3 The River - WQRV - Meridianville/Huntsville, AL'
+        : index === 390
+          ? 'La Zeta (Hermosillo) - 93.9 FM - XHHY - Uniradio - Hermosillo, Sonora'
+          : `QA Radio ${String(index + 1).padStart(3, '0')}`,
+    lat: -72 + row * 6,
+    lon: -174 + column * 12,
+    streamUrl: `https://audio.example.test/${index}.mp3`,
+    homepage: `https://station.example.test/${index}`,
+    tags: tags[index % tags.length].split(','),
+    languages: index === 360 ? ['Spanish'] : ['English'],
+    state: `Region ${row + 1}`,
+    country: 'United States',
+    countryCode: 'US',
+    metadataTrust: 'untrusted-community',
+    codec: index % 2 ? 'AAC' : 'MP3',
+    bitrate: 128,
+  };
+});