fix: playlist cover art, compilation tag, and year

- ripPlaylist/ripTrackCollection: pre-fetch playlist artwork once, embed in all tracks
- ripTrack: skip per-track album cover when playlist embed is provided
- buildTagMetadata: set COMPILATION=1 and year from playlist publish_date
- beatport: normalize playlistMetadata to include date fields for year extraction
- qobuz: normalize playlist image_rectangle to standard image map

internal/provider/beatport/client.go

@@ -610,12 +610,15 @@ func (c *Client) releaseCollectionMetadata(raw map[string]any, releases []any) m
 func playlistMetadata(raw map[string]any, tracks []any) map[string]any {
 	name := jsonutil.StringFromAny(raw["name"])
 	return map[string]any{
-		"id":           jsonutil.StringFromAny(raw["id"]),
-		"name":         name,
-		"title":        name,
-		"tracks_count": firstPositiveInt(jsonutil.IntFromAny(raw["track_count"]), len(tracks)),
-		"image":        imageMap(raw["image"]),
-		"tracks":       map[string]any{"items": tracks},
+		"id":               jsonutil.StringFromAny(raw["id"]),
+		"name":             name,
+		"title":            name,
+		"tracks_count":     firstPositiveInt(jsonutil.IntFromAny(raw["track_count"]), len(tracks)),
+		"image":            imageMap(raw["image"]),
+		"publish_date":     jsonutil.StringFromAny(raw["publish_date"]),
+		"new_release_date": jsonutil.StringFromAny(raw["new_release_date"]),
+		"release_date":     jsonutil.StringFromAny(raw["release_date"]),
+		"tracks":           map[string]any{"items": tracks},
 	}
 }