refactor(outliner): make bullet point the drag handle and remove separate grip icon

frontend/src/features/workspace/OutlinerBlock.tsx

@@ -4,7 +4,6 @@ import {
   ChevronDown,
   Check,
   X,
-  GripVertical,
   Code,
   Heading1,
   Heading2,
@@ -444,20 +443,8 @@ export const OutlinerBlock: React.FC<OutlinerBlockProps> = ({
           />
         ))}
 
-      {/* Bullet Controls: Drag Handle, Collapse Toggle, Bullet / Checkbox */}
+      {/* Bullet Controls: Collapse Toggle & Bullet (Drag-Handle & Zoom) / Checkbox */}
       <div className="flex items-center gap-0.5 pt-1 select-none shrink-0">
-        {canEdit && (
-          <button
-            type="button"
-            draggable
-            onDragStart={() => onDragStartBlock?.(index)}
-            title="Block ziehen oder umwandeln"
-            className="opacity-0 group-hover:opacity-100 focus:opacity-100 p-0.5 text-faint hover:text-main cursor-grab active:cursor-grabbing transition-opacity"
-          >
-            <GripVertical className="w-3.5 h-3.5" />
-          </button>
-        )}
-
         {hasChildren ? (
           <button
             type="button"
@@ -496,9 +483,17 @@ export const OutlinerBlock: React.FC<OutlinerBlockProps> = ({
         ) : (
           <button
             type="button"
+            draggable={canEdit}
+            onDragStart={() => canEdit && onDragStartBlock?.(index)}
             onClick={() => onZoomBlock?.(block.id)}
-            className="w-4 h-4 flex items-center justify-center rounded-btn hover:bg-panel-hover group/bullet transition-transform"
+            className={`w-4 h-4 flex items-center justify-center rounded-btn hover:bg-panel-hover group/bullet transition-transform ${
-            title="Klick: In diesen Ast hineinzoomen (Fokus-Modus)"
+              canEdit ? 'cursor-grab active:cursor-grabbing' : 'cursor-pointer'
+            }`}
+            title={
+              canEdit
+                ? 'Ziehen zum Verschieben • Klick: Ast hineinzoomen (Fokus-Modus)'
+                : 'Klick: In diesen Ast hineinzoomen (Fokus-Modus)'
+            }
           >
             <span
               className={`w-1.5 h-1.5 rounded-full transition-all ${