polish: card hover overlay, reduce cover art shadow bleed

- Add subtle white overlay (4-6% opacity) to GameCard on hover/highlight for clearer feedback
- Reduce ConsoleGameDetail coverArt shadow blur from 0.7 to 0.25 and offset from 12 to 8 to prevent bleeding

src/qml/ConsoleGameDetail.qml

@@ -110,10 +110,10 @@ Item {
                 layer.enabled: true
                 layer.effect: MultiEffect {
                     shadowEnabled: true
-                    shadowColor: Qt.rgba(0, 0, 0, 0.7)
-                    shadowBlur: 0.7
+                    shadowColor: Qt.rgba(0, 0, 0, 0.5)
+                    shadowBlur: 0.25
                     shadowHorizontalOffset: 0
-                    shadowVerticalOffset: 12
+                    shadowVerticalOffset: 8
                 }
 
                 Image {

src/qml/GameCard.qml

@@ -77,6 +77,13 @@ Item {
                 visible: gameCard.coverStatus !== Image.Ready
             }
 
+            Rectangle {
+                anchors.fill: parent
+                radius: parent.radius
+                color: Qt.rgba(1, 1, 1, gameCard.isHighlighted ? 0.06 : (hoverHandler.hovered ? 0.04 : 0.0))
+                Behavior on color { ColorAnimation { duration: Kirigami.Units.shortDuration } }
+            }
+
             Rectangle {
                 anchors.left: parent.left
                 anchors.right: parent.right