Remove drag handle icon (::) for cleaner UI

- Remove ⋮⋮ icon from drag handle
- Keep drag-handle element for proper spacing and functionality
- Set opacity to 0 to hide without removing functionality
- Maintains draggable area for reordering stopwatches

Author: johmara

src/app/app.component.css

@@ -226,18 +226,17 @@ header h1 {
 }
 
 .drag-handle {
-  font-size: 1.2rem;
-  color: var(--main-color);
-  opacity: 0.3;
-  transition: opacity 0.2s;
+  min-width: 24px;
+  min-height: 24px;
   cursor: grab;
   user-select: none;
   display: flex;
   align-items: center;
+  opacity: 0;
 }
 
 .stopwatch-card:hover .drag-handle {
-  opacity: 0.6;
+  opacity: 0;
 }
 
 .stopwatch-header {

src/app/app.component.html

@@ -82,7 +82,7 @@ <h1>Multi-Stopwatch Timer</h1>
       (dragend)="onDragEnd()"
     >
       <div class="card-actions">
-        <div class="drag-handle drag-handle-left" title="Drag to reorder">⋮⋮</div>
+        <div class="drag-handle drag-handle-left"></div>
         <div class="card-actions-right">
           <button 
             class="btn-edit-time"