feat(web): 侧边栏一级目录分组可折叠

新增 CollapsibleDirectoryGroup 组件，点击目录标题可展开/折叠子菜单，
默认展开，导航到子菜单时自动展开。侧边栏整体折叠时回落到图标模式。

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

apps/web/src/index.css

@@ -866,6 +866,37 @@ body {
   color: var(--erp-text-tertiary);
 }
 
+/* Sidebar collapsible directory group */
+.erp-sidebar-group-toggle {
+  display: flex;
+  align-items: center;
+  padding: 16px 20px 6px;
+  font-size: 11px;
+  font-weight: 600;
+  text-transform: uppercase;
+  letter-spacing: 0.8px;
+  color: var(--erp-text-tertiary);
+  cursor: pointer;
+  user-select: none;
+}
+
+.erp-sidebar-group-toggle:hover {
+  color: var(--erp-text-secondary);
+}
+
+.erp-sidebar-group-arrow {
+  display: flex;
+  align-items: center;
+  margin-right: 6px;
+  font-size: 10px;
+}
+
+.erp-sidebar-group-label {
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+
 /* ====================================================================
  * MainLayout — CSS classes replacing inline styles
  * ==================================================================== */

apps/web/src/layouts/MainLayout.tsx

@@ -222,6 +222,108 @@ function isLeafType(menuType: string): boolean {
   return menuType === 'menu' || menuType === 'page';
 }
 
+// 一级目录分组（可折叠）
+const CollapsibleDirectoryGroup = memo(function CollapsibleDirectoryGroup({
+  directory,
+  collapsed,
+  currentPath,
+  onNavigate,
+}: {
+  directory: MenuInfo;
+  collapsed: boolean;
+  currentPath: string;
+  onNavigate: (key: string) => void;
+}) {
+  const [expanded, setExpanded] = useState(true);
+  const visibleChildren = directory.children?.filter((c) => c.visible !== false) || [];
+  const hasActive = visibleChildren.some((c) => {
+    if (c.menu_type === 'directory') {
+      return c.children?.some((gc) => currentPath === (gc.path || gc.id));
+    }
+    return currentPath === (c.path || c.id);
+  });
+
+  useEffect(() => {
+    if (hasActive) setExpanded(true); // eslint-disable-line react-hooks/set-state-in-effect -- 导航到子菜单时自动展开分组
+  }, [hasActive]);
+
+  if (collapsed) {
+    return (
+      <>
+        {visibleChildren.filter((c) => isLeafType(c.menu_type)).map((child) => (
+          <SidebarMenuItem
+            key={child.id}
+            item={{
+              key: child.path || child.id,
+              icon: getIcon(child.icon),
+              label: child.title,
+            }}
+            isActive={currentPath === (child.path || child.id)}
+            collapsed
+            onClick={() => onNavigate(child.path || child.id)}
+          />
+        ))}
+      </>
+    );
+  }
+
+  return (
+    <div>
+      <div
+        className="erp-sidebar-group-toggle"
+        onClick={() => setExpanded((e) => !e)}
+      >
+        <span className="erp-sidebar-group-arrow">
+          <RightOutlined
+            style={{ fontSize: 10, transition: 'transform 0.2s', transform: expanded ? 'rotate(90deg)' : 'rotate(0deg)' }}
+          />
+        </span>
+        <span className="erp-sidebar-group-label">{directory.title}</span>
+      </div>
+      <div
+        className="erp-sidebar-group-content"
+        style={{
+          maxHeight: expanded ? '2000px' : '0px',
+          overflow: 'hidden',
+          transition: 'max-height 0.25s ease',
+        }}
+      >
+        <div className="erp-sidebar-menu">
+          {visibleChildren.map((child) => {
+            if (child.menu_type === 'directory') {
+              return (
+                <CollapsibleSubGroup
+                  key={child.id}
+                  directory={child}
+                  collapsed={collapsed}
+                  currentPath={currentPath}
+                  onNavigate={onNavigate}
+                />
+              );
+            }
+            if (isLeafType(child.menu_type)) {
+              return (
+                <SidebarMenuItem
+                  key={child.id}
+                  item={{
+                    key: child.path || child.id,
+                    icon: getIcon(child.icon),
+                    label: child.title,
+                  }}
+                  isActive={currentPath === (child.path || child.id)}
+                  collapsed={collapsed}
+                  onClick={() => onNavigate(child.path || child.id)}
+                />
+              );
+            }
+            return null;
+          })}
+        </div>
+      </div>
+    </div>
+  );
+});
+
 // 动态菜单渲染（支持多级嵌套）
 const DynamicMenuSection = memo(function DynamicMenuSection({
   menus,
@@ -238,42 +340,14 @@ const DynamicMenuSection = memo(function DynamicMenuSection({
     <>
       {menus.map((menu) => {
         if (menu.menu_type === 'directory') {
-          const visibleChildren = menu.children?.filter((c) => c.visible !== false) || [];
           return (
-            <div key={menu.id}>
+            <CollapsibleDirectoryGroup
-              {!collapsed && <div className="erp-sidebar-group">{menu.title}</div>}
+              key={menu.id}
-              <div className="erp-sidebar-menu">
+              directory={menu}
-                {visibleChildren.map((child) => {
+              collapsed={collapsed}
-                  if (child.menu_type === 'directory') {
+              currentPath={currentPath}
-                    return (
+              onNavigate={onNavigate}
-                      <CollapsibleSubGroup
+            />
-                        key={child.id}
-                        directory={child}
-                        collapsed={collapsed}
-                        currentPath={currentPath}
-                        onNavigate={onNavigate}
-                      />
-                    );
-                  }
-                  if (isLeafType(child.menu_type)) {
-                    return (
-                      <SidebarMenuItem
-                        key={child.id}
-                        item={{
-                          key: child.path || child.id,
-                          icon: getIcon(child.icon),
-                          label: child.title,
-                        }}
-                        isActive={currentPath === (child.path || child.id)}
-                        collapsed={collapsed}
-                        onClick={() => onNavigate(child.path || child.id)}
-                      />
-                    );
-                  }
-                  return null;
-                })}
-              </div>
-            </div>
           );
         }
         if (isLeafType(menu.menu_type) && menu.visible !== false) {