fix: 修复前端侧边栏弹出异常问题

frontend/src/App.tsx

@@ -316,7 +316,7 @@ function AppContent() {
         sessions={sessions}
         activeSessionId={activeSessionId}
         open={sidebarOpen}
-        onToggle={() => setSidebarOpen((v) => !v)}
+        onClose={() => setSidebarOpen(false)}
         onNewSession={handleNewSession}
         onSelectSession={handleSelectSession}
         onDeleteSession={handleDeleteSession}