Fix cache IDs and discover route for music/book types

server/lib/cache.ts

@@ -4,6 +4,8 @@ export type AvailableCacheIds =
   | 'tmdb'
   | 'radarr'
   | 'sonarr'
+  | 'lidarr'
+  | 'readarr'
   | 'rt'
   | 'imdb'
   | 'github'
@@ -50,6 +52,8 @@ class CacheManager {
     }),
     radarr: new Cache('radarr', 'Radarr API'),
     sonarr: new Cache('sonarr', 'Sonarr API'),
+    lidarr: new Cache('lidarr', 'Lidarr API'),
+    readarr: new Cache('readarr', 'Readarr API'),
     rt: new Cache('rt', 'Rotten Tomatoes API', {
       stdTtl: 43200,
       checkPeriod: 60 * 30,

server/routes/discover.ts

@@ -737,7 +737,9 @@ discoverRoutes.get('/trending', async (req, res, next) => {
       }),
     } as const;
 
-    const { data, mapper, type } = await trendingFetchers[mediaType]();
+    // Music/book don't have TMDB trending - fall back to 'all'
+    const fetcherKey = (mediaType === 'music' || mediaType === 'book') ? 'all' : mediaType;
+    const { data, mapper, type } = await trendingFetchers[fetcherKey]();
 
     const media = await Media.getRelatedMedia(
       req.user,