fix(route/apple/podcast): adapt to new serialized-server-data structure (#21387)

Apple Podcasts changed the `#serialized-server-data` element from a
direct array to an object wrapper `{ data: [...], userTokenHash }`.

This broke the route with:
  TypeError: Cannot read properties of undefined (reading 'data')

Changes:
- Handle both old (array) and new (object with `data` key) formats
  using `Array.isArray()` check for backward compatibility
- Add defensive optional chaining on the `channel` relationship
  access chain to prevent crashes when episodes lack channel data

Fixes the same underlying issue reported by yt-dlp (yt-dlp/yt-dlp#15926).

Made-with: Cursor

Co-authored-by: xbankeradmin <admin@xbanker.ai>

lib/routes/apple/podcast.ts

@@ -43,8 +43,9 @@ async function handler(ctx) {
 
     const $ = load(response);
 
-    const serializedServerData = JSON.parse($('#serialized-server-data').text());
-    const header = serializedServerData[0].data.shelves.find((item) => item.contentType === 'showHeaderRegular').items[0];
+    const rawServerData = JSON.parse($('#serialized-server-data').text());
+    const serverData = (Array.isArray(rawServerData) ? rawServerData : rawServerData.data)[0].data;
+    const header = serverData.shelves.find((item) => item.contentType === 'showHeaderRegular').items[0];
 
     const bearerToken = await cache.tryGet(
         'apple:podcast:bearer',
@@ -93,7 +94,7 @@ async function handler(ctx) {
         };
     });
 
-    const channel = episodeReponse.data.find((d) => d.type === 'podcast-episodes').relationships.channel.data.find((d) => d.type === 'podcast-channels')?.attributes;
+    const channel = episodeReponse.data.find((d) => d.type === 'podcast-episodes')?.relationships?.channel?.data?.find((d) => d.type === 'podcast-channels')?.attributes;
 
     return {
         title: channel?.name ?? header.title,