reveal lock screen background as first hex wave passes

shell/applets/HexWaveBackground.qml

@@ -7,6 +7,7 @@ Item {
 
     property bool running: false
     property bool reducedMotion: S.Theme.reducedMotion
+    readonly property real wavePhase: fx.uWavePhase
 
     Rectangle {
         anchors.fill: parent

shell/lock/LockSurface.qml

@@ -13,12 +13,9 @@ WlSessionLockSurface {
 
     color: S.Theme.base00
 
-    property real _bgOpacity: 0
-    NumberAnimation on _bgOpacity {
-        to: 1
-        duration: 400
-        easing.type: Easing.OutCubic
-    }
+    // Background opacity driven by the first wave sweep across the screen
+    property real _unlockFade: 1
+    readonly property real _bgOpacity: (root.width > 0 ? Math.max(0, Math.min(1, _hexWave.wavePhase / root.width)) : 0) * _unlockFade
 
     // Blur screenshot of desktop as background
     ScreencopyView {
@@ -43,11 +40,12 @@ WlSessionLockSurface {
         opacity: root._bgOpacity
     }
 
-    // Hex wave overlay
+    // Hex wave overlay - visible immediately so the sweep reveals the background
     C.HexWaveBackground {
+        id: _hexWave
         anchors.fill: parent
         running: root.lock.secure
-        opacity: root._bgOpacity * 0.4
+        opacity: 0.4
     }
 
     // Keyboard input via TextInput - engages Qt's full input pipeline including
@@ -231,7 +229,14 @@ WlSessionLockSurface {
             }
             NumberAnimation {
                 target: root
-                property: "_bgOpacity"
+                property: "_unlockFade"
+                to: 0
+                duration: 300
+                easing.type: Easing.InCubic
+            }
+            NumberAnimation {
+                target: _hexWave
+                property: "opacity"
                 to: 0
                 duration: 300
                 easing.type: Easing.InCubic