Add a coffee break

Every so often a mug appears at the cat's nose, it sits down, dips its head in
and takes a few slow sips while steam rises. M01, optional stop.

The mug lives in its own click-through window like the chip, or inside the
overlay on Wayland. It goes away as soon as the cat is petted, dragged, sent to
sleep or moves on to something else, so no mug is ever left standing.

Also renames OverlayWindow's mode flag, which shadowed QWindow::active.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

qml/OverlayWindow.qml

@@ -15,7 +15,7 @@ Window {
 
     // Fullscreen is a visibility, not a visible flag, so the mode switch has to
     // go through visibility or the two fight each other.
-    property bool active: false
+    property bool overlayActive: false
 
     readonly property int catW: settings.catSize
     readonly property int catH: Math.round(settings.catSize * 0.9)
@@ -26,14 +26,14 @@ Window {
         Platform.setInputRegion(win, Qt.rect(Math.round(cat.x), Math.round(groundY), catW, catH))
     }
 
-    visibility: active ? Window.FullScreen : Window.Hidden
+    visibility: overlayActive ? Window.FullScreen : Window.Hidden
     color: "transparent"
     flags: Qt.FramelessWindowHint | Qt.WindowStaysOnTopHint | Qt.Tool
            | Qt.NoDropShadowWindowHint | Qt.WindowDoesNotAcceptFocus
     title: qsTr("TNCat")
 
-    onActiveChanged: {
-        if (!active)
+    onOverlayActiveChanged: {
+        if (!overlayActive)
             return
         cat.stageWidth = width
         cat.catWidth = catW
@@ -51,7 +51,7 @@ Window {
     // Coalesce mask updates: one X11 round trip per frame of walking is plenty.
     Timer {
         interval: 33
-        running: win.active
+        running: win.overlayActive
         repeat: true
         onTriggered: win.refreshInputRegion()
     }
@@ -69,6 +69,14 @@ Window {
         }
     }
 
+    Cup {
+        x: win.cat.cupX - width / 2
+        y: win.height - height - win.settings.bottomMargin
+        width: Math.round(win.settings.catSize * 0.38)
+        height: Math.round(width * 1.18)
+        visible: win.cat.cupVisible
+    }
+
     Item {
         id: catItem
         x: win.cat.x