Click-and-drag reordering of favourites bar items in convergence
mode. The existing touch-based press-and-hold drag is kept for
mobile; in convergence mode, press-and-hold opens the context
menu only.
DelegateTouchArea owns the exclusive mouse grab at the C++ level,
so drag detection (threshold crossing + delta signals) is added
there rather than using a QML DragHandler. Displaced items
animate into their new positions while the dragged item follows
the cursor.
Expose FavouritesModel::moveEntry as Q_INVOKABLE so QML can
persist the reorder.
Right-click a running task icon to pin the app to the dock
favourites bar. Pinned apps show a "Remove from Dock" action.
The dock overlay renders as a LayerTop window so context menus
and the dock itself stay above application windows. Menus use
popupType Window to avoid clipping inside the narrow dock
surface.
Currently delegates do not get deleted when removed from models. Due to
the complexity of drag state and other objects, we can't simply delete
the delegate when removed from the model because they might still be
involved in animations or other state at the time of removal. Use smart
pointers to have the delegate objects deleted instead.
QML unfortunately doesn't support QSharedPointer, so we need to expose raw pointers to it.
This fixes in issue where the favorites bar icons would previously animate based off of position changes. This was causing unwanted animations in situations like screen rotation and login.
