Fix body editor under the Breeze style

The body editor was a TextArea with a custom background inside a
ScrollView. Under the Breeze QML style that raised "Unable to assign
TextArea to QQuickTextInput" (Breeze's TextArea.qml rejects a custom
background in that nesting).

Switch to the Qt-recommended idiom: a Flickable with
TextArea.flickable: TextArea { background: null }, wrapped in a plain
Rectangle that provides the border/background. Keeps monospace wrapping,
seed-on-open, Ctrl+Enter save and Esc cancel; adds a vertical ScrollBar.

GUI builds clean.

(The separate "startDrag() drag must be active" log was the previous
binary; the a3d2c49 fix removes it — relaunch to clear.)

ui/qml/OutlineView.qml

@@ -1306,25 +1306,37 @@ ListView {
                         del.editingBody = false
                     }
 
-                    ScrollView {
+                    // Bordered scroll frame holding the editor. Uses the
+                    // Flickable + TextArea.flickable idiom (not ScrollView),
+                    // which the Breeze style accepts; a custom background on a
+                    // styled TextArea trips Breeze's TextArea internals.
+                    Rectangle {
                         Layout.fillWidth: true
                         Layout.preferredHeight: Math.min(
                             Math.max(bodyEditor.contentHeight + 16, outline.baseFontSize * 6),
                             outline.baseFontSize * 20)
-                        clip: true
+                        color: theme.baseColor
+                        border.color: theme.midColor
+                        border.width: 1
+                        radius: 3
 
-                        TextArea {
+                        Flickable {
+                            id: bodyFlick
+                            anchors.fill: parent
+                            anchors.margins: 4
+                            clip: true
+                            contentWidth: width
+                            contentHeight: bodyEditor.contentHeight
+                            boundsBehavior: Flickable.StopAtBounds
+                            ScrollBar.vertical: ScrollBar {}
+
+                            TextArea.flickable: TextArea {
                                 id: bodyEditor
                                 wrapMode: TextArea.Wrap
                                 font.family: "monospace"
                                 font.pointSize: outline.baseFontSize
                                 selectByMouse: true
-                            background: Rectangle {
-                                color: theme.baseColor
-                                border.color: theme.midColor
-                                border.width: 1
-                                radius: 3
-                            }
+                                background: null
                                 // Seed from the raw body when the editor opens.
                                 onVisibleChanged: {
                                     if (visible) {
@@ -1346,6 +1358,7 @@ ListView {
                                 }
                             }
                         }
+                    }
 
                     // Editor toolbar.
                     RowLayout {