Fix minor UI bugs and clean up dead code

Clamp FavouritesBar window indicator dots to at least 1 so a
running task with an empty WinIdList still shows a dot. Add
Accessible.onPressAction to CategoryPanel tiles. Remove dead
convergence-mode property bindings from NavigationPanelComponent
since it is hidden in that mode. Use HTML video tags for .webm
files in README so they render as playable video.

README.md

@@ -4,9 +4,9 @@
 
 ### Desktop demos
 
-![Desktop overview](screenshots/quick_DesktopDemo.webm)
-![Docked mode](screenshots/quick_DesktopDemo_docked.webm)
-![Tiling](screenshots/quick_DesktopDemo_tiling.webm)
+<video src="screenshots/quick_DesktopDemo.webm" controls width="600" alt="Desktop overview"></video>
+<video src="screenshots/quick_DesktopDemo_docked.webm" controls width="600" alt="Docked mode"></video>
+<video src="screenshots/quick_DesktopDemo_tiling.webm" controls width="600" alt="Tiling"></video>
 
 Shift is a fork of [plasma-mobile](https://invent.kde.org/plasma/plasma-mobile).
 The upstream phone UI is untouched; convergence adds a layer on top.

containments/homescreens/folio/qml/CategoryPanel.qml

@@ -191,6 +191,7 @@ Rectangle {
 
                         Accessible.role: Accessible.Button
                         Accessible.name: tile.catName
+                        Accessible.onPressAction: root.categorySelected(tile.catId)
 
                         Rectangle {
                             anchors.fill: parent

containments/homescreens/folio/qml/FavouritesBar.qml

@@ -916,7 +916,7 @@ MouseArea {
                 Repeater {
                     model: {
                         var ids = taskDelegate.model.WinIdList
-                        return ids ? ids.length : 1
+                        return Math.max(1, ids ? ids.length : 0)
                     }
 
                     Rectangle {

containments/taskpanel/qml/NavigationPanelComponent.qml

@@ -37,11 +37,6 @@ MobileShell.NavigationPanel {
     foregroundColorGroup: forcedComplementary ? Kirigami.Theme.Complementary : Kirigami.Theme.Window
     shadow: forcedComplementary
 
-    // Convergence mode: expose running-app task strip
-    convergenceMode: ShellSettings.Settings.convergenceModeEnabled
-    taskModel: tasksModel
-    virtualDesktopInfo: virtualDesktopInfo
-
     MobileShellState.PanelSettingsDBusClient {
         id: panelSettings
         screenName: Screen.name