tree: nested children for initial load

wwwroot/api/workspace_tree.dspy

@@ -1,4 +1,4 @@
-# workspace_tree.dspy - 懒加载：返回指定节点的直接子目录
+# workspace_tree.dspy - 初始加载返回嵌套结构（根节点+children），展开时返回平级子节点
 
 import os
 
@@ -30,25 +30,46 @@ async with DBPools().sqlorContext(dbname) as sor:
 
 if not ws_dir or not os.path.isdir(ws_dir):
     if not node_id:
-        return [{"id": "__root__", "parentid": "", "label": "📁 工作空间（不可用）", "path": ws_dir, "is_leaf": False}]
+        return [{
+            "id": "__root__",
+            "parentid": "",
+            "label": "📁 工作空间（不可用）",
+            "path": ws_dir,
+            "is_leaf": True
+        }]
     return []
 
-# 初始加载：无 id，返回根节点
+# 初始加载：返回带 children 的嵌套结构
 if not node_id:
-    return [{
+    root = {
         "id": "__root__",
         "parentid": "",
         "label": "📁 " + os.path.basename(ws_dir),
         "path": ws_dir,
-        "is_leaf": False
-    }]
-
-# 展开节点：id=__root__ → 扫描 ws_dir。否则拼完整路径
-if node_id == '__root__':
-    scan_path = ws_dir
-else:
-    scan_path = ws_dir + '/' + node_id
+        "is_leaf": False,
+        "children": []
+    }
+    try:
+        entries = sorted(os.listdir(ws_dir))
+    except Exception:
+        entries = []
+    for name in entries:
+        full = os.path.join(ws_dir, name)
+        if name.startswith('.') or name == '__pycache__':
+            continue
+        if os.path.isdir(full):
+            root["children"].append({
+                "id": name,
+                "parentid": "__root__",
+                "label": "📁 " + name,
+                "path": full,
+                "is_leaf": False,
+                "children": []
+            })
+    return [root]
 
+# 展开节点
+scan_path = ws_dir + '/' + node_id
 if not os.path.isdir(scan_path):
     return []
 
@@ -63,9 +84,8 @@ for name in entries:
     if name.startswith('.') or name == '__pycache__':
         continue
     if os.path.isdir(full):
-        rel_path = node_id + '/' + name if node_id != '__root__' else name
         items.append({
-            "id": rel_path,
+            "id": node_id + '/' + name,
             "parentid": node_id,
             "label": "📁 " + name,
             "path": full,