feat(web): align the web UI with the design prototype

- Ambient background in the app shell: three drifting blurred blobs,
  the third one tinted with the current track's cover; can be turned off
  in settings and stays still with reduced motion.
- Island player variant (floating glass panel) next to the bar, chosen
  in settings; player source line ("Album · …", "My Wave"), reactions
  around the transport controls, queue drawer.
- Sidebar: like / dislike counters, pending uploads badge on Queue,
  admin Settings page holding the upload queue limits.
- Collection: header tile with kicker, underline tabs, time / number
  lead column with an equalizer for the current track, album column,
  dimmed dislikes with undo, Play all / Shuffle pills.
- Album: cover-tinted header and Play / Shuffle; artist: artist wave,
  Play and popular tracks (new GET /artists/{id}/top-tracks).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

services/api/internal/library/handler.go

@@ -469,6 +469,26 @@ func (h *Handler) GetAlbum(ctx context.Context, req gen.GetAlbumRequestObject) (
 	return out, nil
 }
 
+// ListArtistTopTracks реализует gen.StrictServerInterface.
+func (h *Handler) ListArtistTopTracks(ctx context.Context, req gen.ListArtistTopTracksRequestObject) (gen.ListArtistTopTracksResponseObject, error) {
+	if _, err := h.store.Artist(ctx, req.Id); err != nil {
+		return nil, catalogErr(err)
+	}
+	limit := 10
+	if req.Params.Limit != nil {
+		limit = min(max(*req.Params.Limit, 1), 50)
+	}
+	rows, err := h.store.ArtistTopTracks(ctx, req.Id, limit)
+	if err != nil {
+		return nil, err
+	}
+	items, err := h.Tracks(ctx, rows)
+	if err != nil {
+		return nil, err
+	}
+	return gen.ListArtistTopTracks200JSONResponse{Items: items}, nil
+}
+
 // GetTrack реализует gen.StrictServerInterface.
 func (h *Handler) GetTrack(ctx context.Context, req gen.GetTrackRequestObject) (gen.GetTrackResponseObject, error) {
 	t, err := h.store.Track(ctx, req.Id)