feat(slint): Playlist Manager + search most-popular hero polish

Playlist Manager: list view renders compact rows with total play time; folder grid cards no longer clip the playlist count (content-driven height); list view shows compact folder chips; the move-to-folder menu gains a folder search and a 4-row scroll cap. Search: the most-popular track hero is resized to the artist-card height with the quality shown as centered text instead of a clipped badge.

cc

crates/qbz-slint/ui/search/SearchResultsView.slint

@@ -491,6 +491,7 @@ export component SearchResultsView inherits Rectangle {
                         }
                         if SearchState.most-popular-kind == "track": SearchTrackHero {
                             track: SearchState.most-popular-track;
+                            quality-label: SearchState.most-popular-quality-label;
                             media-action(k, i, a) => { root.media-action(k, i, a); }
                         }
                     }