Fix UI lag when switching virtual desktop

Fixes the UI lag caused by the floating panel animation

sonic-workspace/sonic-workspace-6.6.4-x11-panel-lag.patch

@@ -0,0 +1,42 @@
+From: Anders da Silva Rytter Hansen <andersrh@users.noreply.github.com>
+Date: Thu, 2 Jul 2026 09:40:00 -0300
+Subject: [PATCH] shell: handle zero-duration floating panel animation
+
+The QML side now disables the floating panel animation by setting
+floatingnessAnimationDuration to 0. With a zero-duration
+QPropertyAnimation the valueChanged signal may not be emitted, so update
+m_floatingness and the QML property synchronously before doing the
+geometry/mask/strut updates.
+
+References: https://bugs.kde.org/show_bug.cgi?id=484501 and https://github.com/orgs/Sonic-DE/discussions/20
+---
+ shell/panelview.cpp | 11 +++++++++++
+ 1 file changed, 11 insertions(+)
+
+diff --git a/shell/panelview.cpp b/shell/panelview.cpp
+--- a/shell/panelview.cpp
++++ b/shell/panelview.cpp
+@@ -1782,6 +1782,13 @@ void PanelView::updateFloating()
+     m_topFloatingPadding = rootObject()->property("fixedTopFloatingPadding").toInt();
+     m_bottomFloatingPadding = rootObject()->property("fixedBottomFloatingPadding").toInt();
+ 
++    const bool instantAnimation = m_floatingnessAnimation.duration() == 0;
++    if (instantAnimation) {
++        // Skip the animation; jump straight to the target value.
++        m_floatingness = m_floatingnessAnimation.endValue().toDouble();
++        rootObject()->setProperty("floatingness", m_floatingness);
++    }
++
+     positionAndResizePanel();
+     updateExclusiveZone();
+     updateShadows();
+@@ -1789,6 +1796,10 @@ void PanelView::updateFloating()
+     // positionPanel and updateMask are called by m_floatingnessAnimation
+     if (m_floatingnessAnimation.targetObject()) {
++        if (instantAnimation) {
++            updateMask();
++            return;
++        }
+         m_floatingnessAnimation.start();
+     }
+ }