the sheet scrims its own window, not the screen

surfaces/quickshell/modules/souveraine/windowSheet/WindowSheet.qml

@@ -70,6 +70,10 @@ Scope {
             return;
         }
         scope.target = id;
+        // Ask where that window is, now. The poll runs every two seconds, and
+        // a sheet that opened against two-second-old geometry would scrim the
+        // wrong rectangle for exactly as long as it took to notice.
+        ViewtopControl.refreshWindows();
         scope.sheetOpen = true;
     }
 
@@ -197,18 +201,45 @@ Scope {
             WlrLayershell.keyboardFocus: WlrKeyboardFocus.OnDemand
             exclusionMode: ExclusionMode.Ignore
 
-            // The scrim. Also the outside-tap target: dismissal by tapping away
+            // The tap-away target. Transparent and full-screen: dismissal by
-            // is load-bearing on a phone, and it is the only exit that needs no
+            // tapping outside is load-bearing on a phone and is the only exit
-            // explanation.
+            // that needs no explanation, so the *catcher* still spans the
-            Rectangle {
+            // glass even though the *scrim* no longer does.
-                anchors.fill: parent
-                color: "#99000000"
-
             MouseArea {
                 anchors.fill: parent
                 onClicked: scope.dismiss()
             }
 
+            // The scrim, over the target window only.
+            //
+            // Casey, 2026-08-05: *"Three finger tap overlay should overlay the
+            // app it's talking about; not all apps."* Dimming everything said
+            // the sheet was about the device; it is about one window, and on a
+            // split screen it was covering the app you were not asking about.
+            //
+            // Geometry comes from the compositor's `workspaces` reply rather
+            // than being computed here — the strip offset and any pose are
+            // facts only it holds, which is the same reason the tap carries its
+            // target instead of a raw point.
+            Rectangle {
+                id: scrim
+                readonly property var target: {
+                    for (const w of ViewtopControl.windows)
+                        if (w.id === scope.target && w.at && w.size)
+                            return w;
+                    return null;
+                }
+                // Falls back to the whole screen when the compositor reported
+                // no geometry. A sheet with no visible subject is confusing;
+                // one that dims everything is merely less precise, and the
+                // buttons still work.
+                x: scrim.target ? scrim.target.at.x : 0
+                y: scrim.target ? scrim.target.at.y : 0
+                width: scrim.target ? scrim.target.size.width : parent.width
+                height: scrim.target ? scrim.target.size.height : parent.height
+                color: "#99000000"
+                radius: scrim.target ? 12 : 0
+
                 Behavior on opacity { NumberAnimation { duration: 120 } }
             }
 
@@ -271,11 +302,13 @@ Scope {
                 }
             }
 
-            // The row. Above centre so a thumb does not cover the window.
+            // The row, centred on the window it acts on rather than on the
+            // panel — a sheet floating mid-screen while the app it names is in
+            // the top half reads as belonging to neither.
             RowLayout {
                 visible: !scope.choosing
-                anchors.horizontalCenter: parent.horizontalCenter
+                x: scrim.x + (scrim.width - width) / 2
-                y: parent.height * 0.38
+                y: scrim.y + scrim.height * 0.38
                 spacing: 28
 
                 SheetButton {