Add GetAlbum RPC with track details and persist metadata on discovery

proto/music_agregator/v1/music_agregator.proto

@@ -5,6 +5,7 @@ option go_package = "homelab.lan/music-agregator/gen/music_agregator/v1/";
 service MusicAgregatorService {
   rpc MonitorAlbum(MonitorAlbumRequest) returns (MonitorAlbumResponse) {}
   rpc GetArtists(GetArtistsRequest) returns (GetArtistsResponse) {}
+  rpc GetAlbum(GetAlbumRequest) returns (GetAlbumResponse) {}
 }
 
 message MonitorAlbumRequest {
@@ -74,6 +75,39 @@ message DownloadInfo {
   string save_path = 4;
 }
 
+message GetAlbumRequest {
+  string album_id = 1;
+}
+
+message GetAlbumResponse {
+  AlbumDetail album = 1;
+  repeated TrackDetail tracks = 2;
+}
+
+message TrackDetail {
+  string id = 1;
+  string external_id = 2;
+  string title = 3;
+  int32 duration_ms = 4;
+  int32 disc_number = 5;
+  int32 track_number = 6;
+  string isrc = 7;
+  bool explicit = 8;
+  repeated ArtistCredit artists = 9;
+  TrackFile file = 10;
+}
+
+message ArtistCredit {
+  string id = 1;
+  string name = 2;
+}
+
+message TrackFile {
+  string path = 1;
+  string format = 2;
+  int64 size = 3;
+}
+
 message MonitoredRelease {
   string info_hash = 1;
   string artist = 2;