fix: keep tree structure in multi-select, checkbox+chevron, separate toggle/expand

frontend/src/components/contacts/ContactFolderTree.tsx

@@ -163,10 +163,11 @@ function FolderTreeItem({
 
   return (
     <div>
-      <div className="flex items-center" style={{ paddingLeft: multiSelectMode ? 8 : depth * 12 + 8 }}>
+      <div className="flex items-center" style={{ paddingLeft: depth * 12 + 8 }}>
         <div
-          draggable
+          draggable={!multiSelectMode}
           onDragStart={(e) => {
+            if (multiSelectMode) return;
             e.dataTransfer.setData('text/folder-id', node.id);
             e.dataTransfer.effectAllowed = 'move';
           }}
@@ -192,13 +193,21 @@ function FolderTreeItem({
           }}
         >
           {multiSelectMode ? (
-            <input
-              type="checkbox"
-              checked={isChecked}
-              onChange={() => onToggleMultiSelect?.(node.id)}
-              onClick={(e) => e.stopPropagation()}
-              className="w-3.5 h-3.5 rounded border-secondary-300 text-primary-600 focus:ring-primary-500 flex-shrink-0 cursor-pointer"
-            />
+            <>
+              <input
+                type="checkbox"
+                checked={isChecked}
+                onChange={() => onToggleMultiSelect?.(node.id)}
+                onClick={(e) => e.stopPropagation()}
+                className="w-3.5 h-3.5 rounded border-secondary-300 text-primary-600 focus:ring-primary-500 flex-shrink-0 cursor-pointer"
+              />
+              <span
+                onClick={(e) => { e.stopPropagation(); setExpanded(!expanded); }}
+                className="flex-shrink-0 cursor-pointer"
+              >
+                {chevron(expanded)}
+              </span>
+            </>
           ) : (
             chevron(expanded)
           )}
@@ -221,24 +230,7 @@ function FolderTreeItem({
         )}
       </div>
 
-      {expanded && !multiSelectMode && node.children.map((child) => (
-        <FolderTreeItem
-          key={child.id}
-          node={child}
-          depth={depth + 1}
-          selectedFilter={selectedFilter}
-          onSelectFolder={onSelectFolder}
-          onMoreClick={onMoreClick}
-          isDragOver={false}
-          onDragOver={onDragOver}
-          onDragLeave={onDragLeave}
-          onDrop={onDrop}
-          multiSelectMode={multiSelectMode}
-          multiSelectedFolders={multiSelectedFolders}
-          onToggleMultiSelect={onToggleMultiSelect}
-        />
-      ))}
-      {multiSelectMode && node.children.map((child) => (
+      {expanded && node.children.map((child) => (
         <FolderTreeItem
           key={child.id}
           node={child}