Add missing Track, Album, Artist model types and client methods

Track: Added FileInfo, FileDownloadInfo, TrackFullInfo, SimilarTracks types
Album: Added AlbumSimilarEntities, AlbumTrailer, SimilarEntityItem types
Artist: Added ArtistSimilar, ArtistLinks, ArtistAbout, ArtistInfo, ArtistSkeleton,
       ArtistTrailerStatus, ArtistLink, Stats, SkeletonBlock types

Client methods added:
- artists.go: GetArtistBriefInfo, GetArtistSimilar, GetArtistLinks, GetArtistAlsoAlbums,
  GetArtistDiscographyAlbums, GetArtistSafeDirectAlbums, GetArtistTrackIds, GetArtistAbout,
  GetArtistDonation, GetArtistInfo, GetArtistSkeleton, GetArtistTrailer
- albums.go: GetAlbumSimilarEntities, GetAlbumTrailer
- tracks.go: GetTracksFileInfo, GetTracksSimilar, GetTrackTrailer, GetTrackFullInfo

internal/models/track.go

@@ -535,3 +535,121 @@ func (tt *TrackTrailer) DeList(data []byte, c ClientInterface) ([]Model, error)
 	}
 	return result, nil
 }
+
+// FileInfo represents file info for a track.
+type FileInfo struct {
+	BaseModel
+	DownloadInfo *FileDownloadInfo `json:"download_info"`
+}
+
+// DeJSON deserializes FileInfo from JSON data.
+func (fi *FileInfo) DeJSON(data []byte, c ClientInterface) (Model, error) {
+	var raw map[string]json.RawMessage
+	if err := json.Unmarshal(data, &raw); err != nil {
+		return nil, err
+	}
+
+	info := &FileInfo{BaseModel: *NewBaseModel(c)}
+
+	if v, ok := raw["download_info"]; ok {
+		var di FileDownloadInfo
+		json.Unmarshal(v, &di)
+		info.DownloadInfo = &di
+	}
+
+	return info, nil
+}
+
+// DeList deserializes a list of FileInfo from JSON data.
+func (fi *FileInfo) DeList(data []byte, c ClientInterface) ([]Model, error) {
+	var rawList []json.RawMessage
+	if err := json.Unmarshal(data, &rawList); err != nil {
+		return nil, err
+	}
+
+	result := make([]Model, 0, len(rawList))
+	for _, item := range rawList {
+		info := &FileInfo{BaseModel: *NewBaseModel(c)}
+		if err := json.Unmarshal(item, info); err != nil {
+			continue
+		}
+		result = append(result, info)
+	}
+	return result, nil
+}
+
+// FileDownloadInfo represents file download info.
+type FileDownloadInfo struct {
+	BaseModel
+	TrackID   string `json:"track_id"`
+	Quality   string `json:"quality"`
+	Codec     string `json:"codec"`
+	Bitrate   int    `json:"bitrate"`
+	Transport string `json:"transport"`
+	URL       string `json:"url"`
+	URLs      []string `json:"urls"`
+	RealID    string `json:"real_id"`
+	Gain      bool   `json:"gain"`
+	Key       string `json:"key"`
+}
+
+// DeJSON deserializes FileDownloadInfo from JSON data.
+func (fdi *FileDownloadInfo) DeJSON(data []byte, c ClientInterface) (Model, error) {
+	var raw map[string]json.RawMessage
+	if err := json.Unmarshal(data, &raw); err != nil {
+		return nil, err
+	}
+
+	info := &FileDownloadInfo{BaseModel: *NewBaseModel(c)}
+
+	if v, ok := raw["track_id"]; ok {
+		json.Unmarshal(v, &info.TrackID)
+	}
+	if v, ok := raw["quality"]; ok {
+		json.Unmarshal(v, &info.Quality)
+	}
+	if v, ok := raw["codec"]; ok {
+		json.Unmarshal(v, &info.Codec)
+	}
+	if v, ok := raw["bitrate"]; ok {
+		json.Unmarshal(v, &info.Bitrate)
+	}
+	if v, ok := raw["transport"]; ok {
+		json.Unmarshal(v, &info.Transport)
+	}
+	if v, ok := raw["url"]; ok {
+		json.Unmarshal(v, &info.URL)
+	}
+	if v, ok := raw["urls"]; ok {
+		json.Unmarshal(v, &info.URLs)
+	}
+	if v, ok := raw["real_id"]; ok {
+		json.Unmarshal(v, &info.RealID)
+	}
+	if v, ok := raw["gain"]; ok {
+		json.Unmarshal(v, &info.Gain)
+	}
+	if v, ok := raw["key"]; ok {
+		json.Unmarshal(v, &info.Key)
+	}
+
+	return info, nil
+}
+
+// DeList deserializes a list of FileDownloadInfo from JSON data.
+func (fdi *FileDownloadInfo) DeList(data []byte, c ClientInterface) ([]Model, error) {
+	var rawList []json.RawMessage
+	if err := json.Unmarshal(data, &rawList); err != nil {
+		return nil, err
+	}
+
+	result := make([]Model, 0, len(rawList))
+	for _, item := range rawList {
+		info := &FileDownloadInfo{BaseModel: *NewBaseModel(c)}
+		if err := json.Unmarshal(item, info); err != nil {
+			continue
+		}
+		result = append(result, info)
+	}
+	return result, nil
+}