fix: align Code return and sidebar collapse in the top row

src/components/layout/Sidebar.tsx

@@ -11,6 +11,7 @@ import {
   FolderKanban,
   Gamepad2,
   LogOut,
+  PanelLeftClose,
   Plus,
   RadioTower,
   Settings as SettingsIcon,
@@ -90,6 +91,7 @@ export function Sidebar({
 }: SidebarProps = {}) {
   const { t } = useTranslation('common');
   const storedSidebarCollapsed = useSettingsStore((state) => state.sidebarCollapsed);
+  const setSidebarCollapsed = useSettingsStore((state) => state.setSidebarCollapsed);
   const sidebarWidth = useSettingsStore((state) => normalizeClassroomSidebarWidth(state.classroomSidebarWidth));
   const sidebarPinnedCollapsed = !forceExpanded && storedSidebarCollapsed;
   const sidebarCollapsed = sidebarPinnedCollapsed && !sidebarPeekOpen;
@@ -412,11 +414,23 @@ export function Sidebar({
         )}
       >
         <div className="min-w-0 w-full">
+          {workspaceLayout && <div className="no-drag flex h-10 min-w-0 items-center gap-1" data-testid="classroom-sidebar-navigation">
+            <ModuleSwitcher sidebarCollapsed={sidebarCollapsed} toolbar />
+            {!sidebarPinnedCollapsed && ['darwin', 'win32'].includes(window.electron?.platform ?? '') && <button
+              type="button"
+              data-testid="titlebar-sidebar-toggle"
+              aria-label="折叠侧栏"
+              title="折叠侧栏"
+              aria-expanded="true"
+              onClick={() => setSidebarCollapsed(true)}
+              className="no-drag motion-press flex h-8 w-8 shrink-0 items-center justify-center rounded-md text-muted-foreground hover:bg-surface-subtle hover:text-foreground"
+            ><PanelLeftClose className="h-4 w-4" /></button>}
+          </div>}
           {workspaceLayout && <button type="button" aria-label="返回首页" title="返回首页" onClick={() => navigate('/module-select')} className="classroom-brand flex w-full items-center gap-2 rounded-lg text-left">
             <span className="classroom-brand-mark"><img src={classroomMark} alt="" className="h-7 w-7" /></span>
             <span className="min-w-0"><span className="block text-base font-semibold tracking-tight">麦洛</span><span className="classroom-brand-caption">把脑洞变成作品</span></span>
           </button>}
-          <ModuleSwitcher sidebarCollapsed={sidebarCollapsed} compact={!sidebarCollapsed} />
+          {!workspaceLayout && <ModuleSwitcher sidebarCollapsed={sidebarCollapsed} compact={!sidebarCollapsed} />}
         </div>
       </div>}