Add Lidarr/Readarr backend support

- Add MUSIC and BOOK to MediaType enum
- Add permission flags for music/book requests
- Create Lidarr API adapter (artist/album search, add, remove)
- Create Readarr API adapter (book/author search, add, remove)
- Add Lidarr/Readarr settings interfaces and routes
- Add music and book API routes for search/detail
- Register all new routes in main router and settings router

server/constants/media.ts

@@ -9,6 +9,8 @@ export enum MediaRequestStatus {
 export enum MediaType {
   MOVIE = 'movie',
   TV = 'tv',
+  MUSIC = 'music',
+  BOOK = 'book',
 }
 
 export enum MediaStatus {