fix(slint): follow chip, playlist card size, track row hover, dedupe

- Follow button on the artist card is no longer a pill — Radius.sm
  rounded rectangle, matching the rest of the app (new ADR-008).
- PlaylistCard sized identically to AlbumCard (220x266) with the same
  220px artwork area; collage and the grid/carousel updated to match.
- Track row play overlay now appears anywhere over the row, not only
  when the pointer is directly over the cell. Slint does not propagate
  has-hover to ancestor TouchAreas, so each row OR-s its own ta with
  every nested TouchArea (play-cell, fav/dl/more) into row-hovered.
- EqualizerBars sit on a fixed 16px baseline so the animation stays
  perfectly centered while the bar heights oscillate.
- TrackPlayCell exposes out hovered so rows can OR it cleanly.
- Search dedupes a top-result artist that is also the first carousel
  entry, removing the redundant duplicate.

cc

crates/qbz-slint/ui/discover/ArtistCard.slint

@@ -4,6 +4,7 @@
 
 import { Theme } from "../foundation/semantic-colors.slint";
 import { Typography } from "../foundation/typography.slint";
+import { Radius } from "../foundation/radius.slint";
 import { SlimItem } from "../state.slint";
 import { QbzIcon } from "../primitives/QbzIcon.slint";
 
@@ -74,7 +75,9 @@ export component ArtistCard inherits Rectangle {
             Rectangle {
                 width: chip-row.preferred-width;
                 height: 30px;
-                border-radius: 15px;
+                // Rectangular with small rounded corners — QBZ never uses
+                // pill-shaped chips (ADR-008).
+                border-radius: Radius.sm;
                 background: follow-ta.has-hover
                     ? Theme.surface-hover
                     : Theme.surface-elevated;

crates/qbz-slint/ui/discover/PlaylistCard.slint

@@ -52,8 +52,8 @@ export component PlaylistCard inherits Rectangle {
     // "queue" | "favorite").
     callback media-action(string, string, string);
 
-    width: 162px;
-    height: 210px;
+    width: 220px;
+    height: 266px;
 
     property <bool> overlay-on: hover.has-hover
         || fav-btn.hovered || play-btn.hovered || more-btn.hovered;
@@ -64,14 +64,14 @@ export component PlaylistCard inherits Rectangle {
 
         // --- Cover collage + hover overlay -------------------------------
         Rectangle {
-            width: 162px;
-            height: 162px;
+            width: 220px;
+            height: 220px;
             border-radius: Radius.sm;
             clip: true;
 
             PlaylistCollage {
                 playlist: root.playlist;
-                size: 162px;
+                size: 220px;
             }
 
             Rectangle {
@@ -93,8 +93,8 @@ export component PlaylistCard inherits Rectangle {
 
             HorizontalLayout {
                 x: 0px;
-                y: 95px;
-                width: 162px;
+                y: 132px;
+                width: 220px;
                 height: 44px;
                 alignment: center;
                 spacing: 12px;
@@ -172,7 +172,7 @@ export component PlaylistCard inherits Rectangle {
 
         // --- Title / subtitle --------------------------------------------
         VerticalLayout {
-            height: 42px;
+            height: 40px;
             spacing: 2px;
             padding-left: Spacing.xs;
             Text {

crates/qbz-slint/ui/discover/PlaylistCarousel.slint

@@ -68,9 +68,9 @@ export component PlaylistCarousel inherits VerticalLayout {
     callback view-all-clicked();
     callback media-action(string, string, string);
 
-    property <length> card-width: 162px;
-    property <length> card-height: 210px;
-    property <length> gap: 24px;
+    property <length> card-width: 220px;
+    property <length> card-height: 266px;
+    property <length> gap: 32px;
 
     property <int> count: root.playlists.length;
     property <int> per-page: Math.max(

crates/qbz-slint/ui/discover/PlaylistCollage.slint

@@ -9,7 +9,7 @@ import { SearchPlaylistItem } from "../state.slint";
 
 export component PlaylistCollage inherits Rectangle {
     in property <SearchPlaylistItem> playlist;
-    in property <length> size: 162px;
+    in property <length> size: 220px;
 
     width: root.size;
     height: root.size;