Unify the drop zones into one component

app/MindWork AI Studio/Assistants/AssistantBase.razor

@@ -4,7 +4,7 @@
 
 @* Every assistant is a drop area: a file dropped anywhere inside it lands on the assistant's
    default zone, while a file dropped on one of its specific zones lands there. *@
-<DropZoneScope Class="inner-scrolling-context">
+<PathDropZone IsArea="@true" Class="inner-scrolling-context">
 
     <MudStack Row="true" AlignItems="AlignItems.Center" Class="mb-2 mr-3" StretchItems="StretchItems.Start">
         <MudText Typo="Typo.h3">
@@ -188,4 +188,4 @@
             </MudStack>
         </FooterContent>
     </InnerScrolling>
-</DropZoneScope>
+</PathDropZone>