fix(workspace): refine folder row drop target, depth-first tree sorting & auto-expansion

frontend/src/features/workspace/WorkspaceView.tsx

@@ -89,7 +89,10 @@ const FolderTreeItem: React.FC<FolderTreeItemProps> = ({
   const hasContent = node.subfolders.length > 0 || node.docs.length > 0;
 
   return (
+    <div className="space-y-0.5">
       <div
+        draggable
+        onDragStart={(e) => handleFolderDragStart(e, node.fullPath)}
         onDragOver={(e) => {
           e.preventDefault();
           e.stopPropagation();
@@ -100,11 +103,6 @@ const FolderTreeItem: React.FC<FolderTreeItemProps> = ({
           if (dragOverFolder === node.fullPath) setDragOverFolder(null);
         }}
         onDrop={(e) => handleDropOnFolder(node.fullPath, e)}
-      className="space-y-0.5"
-    >
-      <div
-        draggable
-        onDragStart={(e) => handleFolderDragStart(e, node.fullPath)}
         style={{ paddingLeft: `${depth * 12 + 8}px` }}
         className={`group flex items-center justify-between pr-2 py-1 rounded-btn text-xs cursor-pointer transition-colors ${
           isDragOver
@@ -464,7 +462,14 @@ export const WorkspaceView: React.FC<WorkspaceViewProps> = ({
       }
       const res = await api.createFolder(clean);
       setFolders((prev) => (prev.includes(res.path) ? prev : [...prev, res.path].sort()));
-      setExpandedFolders((prev) => ({ ...prev, [res.path]: true }));
+      const parts = res.path.split('/');
+      let acc = '';
+      const expansions: Record<string, boolean> = {};
+      for (const part of parts) {
+        acc = acc ? `${acc}/${part}` : part;
+        expansions[acc] = true;
+      }
+      setExpandedFolders((prev) => ({ ...prev, ...expansions }));
       setNewFolderName('');
       setNewFolderIsShared(false);
       setShowNewFolderModal(false);
@@ -526,6 +531,16 @@ export const WorkspaceView: React.FC<WorkspaceViewProps> = ({
         setDocs((prev) =>
           prev.map((d) => (d.id === docId ? { ...d, folderPath: updatedDoc.folderPath } : d))
         );
+        if (targetFolder) {
+          const parts = targetFolder.split('/');
+          let acc = '';
+          const expansions: Record<string, boolean> = {};
+          for (const part of parts) {
+            acc = acc ? `${acc}/${part}` : part;
+            expansions[acc] = true;
+          }
+          setExpandedFolders((prev) => ({ ...prev, ...expansions }));
+        }
       } catch {
         // ignore
       }
@@ -533,6 +548,16 @@ export const WorkspaceView: React.FC<WorkspaceViewProps> = ({
       triggerHaptic(15);
       try {
         await api.moveFolder(folderPath, targetFolder);
+        if (targetFolder) {
+          const parts = targetFolder.split('/');
+          let acc = '';
+          const expansions: Record<string, boolean> = {};
+          for (const part of parts) {
+            acc = acc ? `${acc}/${part}` : part;
+            expansions[acc] = true;
+          }
+          setExpandedFolders((prev) => ({ ...prev, ...expansions }));
+        }
         loadWorkspaceData();
       } catch {
         // ignore
@@ -672,7 +697,12 @@ export const WorkspaceView: React.FC<WorkspaceViewProps> = ({
       }
     }
 
-    const sortedPaths = Array.from(allPathsSet).sort((a, b) => a.localeCompare(b));
+    const sortedPaths = Array.from(allPathsSet).sort((a, b) => {
+      const depthA = a.split('/').length;
+      const depthB = b.split('/').length;
+      if (depthA !== depthB) return depthA - depthB;
+      return a.localeCompare(b);
+    });
 
     for (const p of sortedPaths) {
       const parts = p.split('/');