feat: GPU切换回退保护逻辑

- switchGpu切换前写入备份文件(.gpu-switch-backup)记录之前模式
- init()检测未确认的切换，启动30秒自动回退计时器
- QML弹出'显示是否正常'确认覆盖层，支持手动确认/回退/超时自动回退
- confirmSwitchSuccess()用户确认正常后删除备份
- restoreFromBackup()自动恢复之前模式并发送通知
- primeOffloadEnabled属性检测当前PRIME offload状态
- switchGpu改用environment.d方式，不需要root/pkexec
- 翻译更新：回退确认相关8条新增

package/driverview.qml

@@ -28,13 +28,8 @@ AppletItem {
 
     // 当前 PRIME 模式（nvidia/on-demand/intel）
     readonly property string currentPrimeMode: {
-        if (root.gpuMode !== "PRIME" || !root.applet || !root.applet.gpuPrimary) return ""
-        var lines = root.deviceInfo.split("\n").filter(function(l) { return l.trim().length > 0 })
-        for (var i = 0; i < lines.length; i++) {
-            if (/nvidia/i.test(lines[i]) && root.applet.gpuPrimary[i] === "true") {
-                return "nvidia"
-            }
-        }
+        if (root.gpuMode !== "PRIME") return ""
+        if (root.applet && root.applet.primeOffloadEnabled) return "nvidia"
         return "on-demand"
     }
 
@@ -1071,6 +1066,98 @@ AppletItem {
             }
         }
 
+        // GPU 切换回退确认覆盖层（启动时检测到未确认的切换）
+        Rectangle {
+            id: restoreOverlay
+            anchors.fill: parent
+            color: Qt.rgba(0, 0, 0, 0.75)
+            radius: 12
+            visible: root.applet && root.applet.switchPending
+            z: 100
+
+            ColumnLayout {
+                anchors.centerIn: parent
+                width: parent.width - 48
+                spacing: 16
+
+                // 警告图标
+                Text {
+                    Layout.alignment: Qt.AlignHCenter
+                    text: "⚠"
+                    font.pixelSize: 36
+                    color: Qt.rgba(245/255, 158/255, 11/255, 1)
+                }
+
+                // 标题
+                Text {
+                    Layout.alignment: Qt.AlignHCenter
+                    text: qsTr("Display OK?")
+                    font.pixelSize: 18
+                    font.bold: true
+                    color: "#e8e8e8"
+                }
+
+                // 说明
+                Text {
+                    Layout.alignment: Qt.AlignHCenter
+                    Layout.fillWidth: true
+                    text: qsTr("GPU mode was changed. If display is abnormal, it will auto-revert in %1s.").arg(root.applet ? root.applet.restoreCountdown : 0)
+                    font.pixelSize: 12
+                    color: "#a0a0a0"
+                    horizontalAlignment: Text.AlignHCenter
+                    wrapMode: Text.WordWrap
+                }
+
+                // 按钮行
+                RowLayout {
+                    Layout.fillWidth: true
+                    spacing: 12
+
+                    // 回退按钮
+                    Button {
+                        Layout.fillWidth: true
+                        Layout.preferredHeight: 34
+                        font.pixelSize: 12
+
+                        background: Rectangle {
+                            color: parent.hovered ? Qt.rgba(220/255, 38/255, 38/255, 0.8) : Qt.rgba(220/255, 38/255, 38/255, 0.3)
+                            radius: 8
+                            border.width: 1
+                            border.color: Qt.rgba(220/255, 38/255, 38/255, 0.6)
+                        }
+                        contentItem: Text {
+                            text: qsTr("Revert")
+                            color: "#ff6b6b"
+                            font.pixelSize: 12
+                            font.bold: true
+                            horizontalAlignment: Text.AlignHCenter
+                        }
+                        onClicked: if (root.applet) root.applet.restoreSwitch()
+                    }
+
+                    // 确认正常按钮
+                    Button {
+                        Layout.fillWidth: true
+                        Layout.preferredHeight: 34
+                        font.pixelSize: 12
+
+                        background: Rectangle {
+                            color: parent.hovered ? Qt.darker(root.accentBlue, 1.2) : root.accentBlue
+                            radius: 8
+                        }
+                        contentItem: Text {
+                            text: qsTr("Display OK")
+                            color: "white"
+                            font.pixelSize: 12
+                            font.bold: true
+                            horizontalAlignment: Text.AlignHCenter
+                        }
+                        onClicked: if (root.applet) root.applet.confirmSwitchSuccess()
+                    }
+                }
+            }
+        }
+
         Component.onCompleted: {
             DockPanelPositioner.bounding = Qt.binding(function () {
                 const point = root.mapToItem(null, root.width / 2, root.height / 2)