fix(launcher): fix search result items not responding to mouse clicks in windowed mode

The MouseArea was bound to `enabled: root.dndEnabled`, which defaults
to false in SearchResultView delegates. This caused the MouseArea to
be completely disabled, preventing onClicked from firing. Meanwhile,
the Button consumed mouse events, blocking the outer TapHandler from
receiving them — resulting in all three click mechanisms failing.

Changed MouseArea to always be enabled and conditionally set
drag.target instead, so click handling works regardless of dndEnabled
while drag behavior remains controlled.

Log: Fix search result items not responding to mouse clicks in windowed mode

Influence:
1. Open the launcher in windowed mode
2. Type a keyword in the search box to trigger the search result list
3. Click on an app icon in the search results and verify it launches correctly
4. Right-click on an app icon in the search results and verify the context menu appears
5. Verify click and drag operations still work correctly in the frequently used and recently installed views

fix: 修复小窗口模式搜索列表中应用无法鼠标点击的问题

MouseArea 的 enabled 绑定到了 root.dndEnabled，而搜索结果的 delegate
未设置该属性，默认值为 false，导致 MouseArea 被完全禁用，onClicked
无法触发。同时 Button 消费了鼠标事件，阻止了外层 TapHandler 接收
事件，导致三层点击机制全部失效。

将 MouseArea 改为始终启用，仅通过 drag.target 条件控制拖拽行为，
使点击处理不再依赖 dndEnabled 的值。

Log: 修复小窗口模式搜索列表中应用无法鼠标点击的问题

Influence:
1. 打开小窗口模式的启动器
2. 在搜索框中输入关键字，触发搜索结果列表
3. 点击搜索结果中的应用图标，验证应用能正常启动
4. 右键点击搜索结果中的应用图标，验证右键菜单正常弹出
5. 验证常用应用和最近安装区域的点击和拖拽操作仍然正常

PMS: BUG-352527

Author: robertkill

qml/windowed/IconItemDelegate.qml

@@ -50,8 +50,8 @@ Control {
             anchors.fill: parent
             hoverEnabled: false
             acceptedButtons: Qt.LeftButton
-            enabled: root.dndEnabled
-            drag.target: root
+            enabled: true
+            drag.target: root.dndEnabled ? root : null
             onPressed: function (mouse) {
                 if (mouse.button === Qt.LeftButton && root.dndEnabled) {
                     appIcon.grabToImage(function(result) {