Improve auto-hide dock reveal

Expand the dock input region as soon as the reveal animation starts
rather than waiting for it to finish, so the cursor can reach dock
items while the panel is still sliding into view.

Introduce updateInputRegion() and call it from onDockOffsetChanged,
onShouldHideChanged, onActiveChanged, onWidthChanged, and onHeightChanged
so the input region is always consistent with the current state.

While hover-revealing with a maximised window present, switch the
LayerShell exclusion zone from -1 to dockHeight so the window tiles
away from the dock instead of being obscured underneath it.

Reduce the hover dwell timer from a hard-coded 300 ms to
Kirigami.Units.shortDuration so the dock is easier to summon.

containments/homescreens/folio/qml/main.qml

@@ -287,7 +287,7 @@ ContainmentItem {
         LayerShell.Window.scope: "dock-overlay"
         LayerShell.Window.layer: LayerShell.Window.LayerTop
         LayerShell.Window.anchors: LayerShell.Window.AnchorBottom | LayerShell.Window.AnchorLeft | LayerShell.Window.AnchorRight
-        LayerShell.Window.exclusionZone: -1
+        LayerShell.Window.exclusionZone: shouldReserveSpace ? dockHeight : -1
         LayerShell.Window.keyboardInteractivity: LayerShell.Window.KeyboardInteractivityOnDemand
 
         // Auto-hide: slide dock content off-screen when a window is
@@ -304,6 +304,25 @@ ContainmentItem {
 
         readonly property bool shouldHide: ShellSettings.Settings.autoHidePanelsEnabled
                                               && windowMaximizedTracker.showingWindow && !hoverRevealing
+        readonly property bool shouldReserveSpace: ShellSettings.Settings.autoHidePanelsEnabled
+                                                   && windowMaximizedTracker.showingWindow && hoverRevealing
+
+        function updateInputRegion() {
+            if (shouldHide && dockOffset >= dockHeight) {
+                MobileShell.ShellUtil.setInputRegion(dockOverlay,
+                    Qt.rect(0, dockOverlay.height - revealStripHeight,
+                            dockOverlay.width, revealStripHeight))
+            } else {
+                MobileShell.ShellUtil.setInputRegion(dockOverlay, Qt.rect(0, 0, 0, 0))
+            }
+        }
+
+        onActiveChanged: {
+            hoverRevealTimer.stop()
+            hoverRevealing = false
+            dockOffset = shouldHide ? dockHeight : 0
+            updateInputRegion()
+        }
 
         onShouldHideChanged: {
             if (shouldHide) {
@@ -311,26 +330,23 @@ ContainmentItem {
             } else {
                 dockOffset = 0
             }
+            updateInputRegion()
         }
 
         // Narrow the input region to a strip at the screen edge when hidden
         // so that app controls near the bottom edge are not accidentally
         // intercepted.  Mirrors the same pattern used by NavigationPanel.
         onDockOffsetChanged: {
-            if (dockOffset >= dockHeight) {
+            updateInputRegion()
-                MobileShell.ShellUtil.setInputRegion(dockOverlay,
-                    Qt.rect(0, dockOverlay.height - revealStripHeight,
-                            dockOverlay.width, revealStripHeight))
-            } else if (dockOffset === 0) {
-                MobileShell.ShellUtil.setInputRegion(dockOverlay, Qt.rect(0, 0, 0, 0))
-            }
         }
+        onWidthChanged: updateInputRegion()
+        onHeightChanged: updateInputRegion()
 
-        // Delay reveal by 300 ms so a quick edge graze does not pop the
+        // Delay reveal briefly so a quick edge graze does not pop the
         // dock up mid-interaction with the underlying application.
         Timer {
             id: hoverRevealTimer
-            interval: 300
+            interval: Kirigami.Units.shortDuration
             repeat: false
             onTriggered: dockOverlay.hoverRevealing = true
         }