Fix album_type field missing from Deezer and Spotify Track dataclasses

Both clients have their own Track class separate from iTunes. The
album preference commit added album_type/total_tracks to from_*_track()
constructors but not to the class definitions, crashing all Deezer and
Spotify discovery searches.

core/deezer_client.py

@@ -58,6 +58,8 @@ class Track:
     release_date: Optional[str] = None
     track_number: Optional[int] = None
     disc_number: Optional[int] = None
+    album_type: Optional[str] = None
+    total_tracks: Optional[int] = None
 
     @classmethod
     def from_deezer_track(cls, track_data: Dict[str, Any]) -> 'Track':

core/spotify_client.py

@@ -297,6 +297,8 @@ class Track:
     external_urls: Optional[Dict[str, str]] = None
     image_url: Optional[str] = None
     release_date: Optional[str] = None
+    album_type: Optional[str] = None
+    total_tracks: Optional[int] = None
 
     @classmethod
     def from_spotify_track(cls, track_data: Dict[str, Any]) -> 'Track':