The CI Flutter SDK predates v3.41 and only exposes ReorderableListView's
onReorder; the newer onReorderItem broke the build with three analyzer
errors. onReorder exists in both SDKs, so use it and compensate for its
pre-removal newIndex internally.
Fixing the call site surfaced a real ordering bug: _onReorder located the
target neighbour in the untrimmed global list, while ServicioFavoritos
.reordenar inserts into the list after the station is removed. Dragging a
station downwards past its neighbours therefore landed it one slot too far.
Adds a mid-list downward-drag test, the only case that separates the two
coordinate spaces.
FreeTLab