feat(gacha): add /api/gachabeta toon-shaded wish style

The beta wish renders an 8-second astrology-themed night sky in toon
shading through a perspective action camera: it dollies toward a hero
cloud, a comet lights the cloud's rim from behind and bursts through it,
the camera chases the comet as its flare builds to a starburst, and the
label appears with an S, SS, or SSS rank. It shares the /api/gacha request
contract and render slots.

renderer/scripts/api-smoke.js

@@ -65,6 +65,21 @@ try {
   }
 
   console.log(`api-smoke gacha: ${gacha.rawPayload.byteLength} bytes`);
+
+  const beta = await app.inject({
+    method: 'POST',
+    url: '/api/gachabeta',
+    headers: {
+      authorization: 'Bearer smoke-token',
+    },
+    payload: {label: 'Bún bò', rarity: 5},
+  });
+
+  if (beta.statusCode !== 200 || beta.rawPayload.subarray(4, 8).toString() !== 'ftyp') {
+    throw new Error(`Expected gachabeta MP4, got ${beta.statusCode}: ${beta.body.slice(0, 200)}`);
+  }
+
+  console.log(`api-smoke gachabeta: ${beta.rawPayload.byteLength} bytes`);
 } finally {
   await app.close();
 }