fix(web): 修复 WebSocket 切换 session 时的错误

- 添加 isClosingRef 标记主动关闭，避免触发错误回调
- 在 effect 开始时重置 isClosingRef 支持 StrictMode
- 增强 Vite 代理错误处理，静默 EPIPE/ECONNRESET 错误

packages/web/vite.config.ts

@@ -61,6 +61,36 @@ export default defineConfig({
         target: 'http://localhost:3000',
         changeOrigin: true,
         ws: true,
+        // 忽略 WebSocket 代理错误（切换 session 时正常发生）
+        configure: (proxy) => {
+          // 静默忽略所有代理错误
+          proxy.on('error', (err, _req, res) => {
+            const msg = err.message || '';
+            // EPIPE/ECONNRESET 是正常的连接关闭错误
+            if (msg.includes('EPIPE') || msg.includes('ECONNRESET') || msg.includes('ECONNREFUSED')) {
+              if (res && 'writeHead' in res && !res.headersSent) {
+                res.writeHead(502);
+                res.end();
+              }
+              return;
+            }
+            console.error('[proxy error]', msg);
+          });
+          // WebSocket 请求阶段错误
+          proxy.on('proxyReqWs', (_proxyReq, _req, socket) => {
+            socket.on('error', () => {});
+          });
+          // WebSocket 响应阶段错误
+          proxy.on('open', (proxySocket) => {
+            proxySocket.on('error', () => {});
+          });
+          // WebSocket 关闭
+          proxy.on('close', (_res, socket) => {
+            if (socket && !socket.destroyed) {
+              socket.destroy();
+            }
+          });
+        },
       },
       '/health': {
         target: 'http://localhost:3000',