refactor(websocket): 重构 WebSocket 和 SSE 连接逻辑以支持开发和生产环境

- 统一处理 WebSocket 和 SSE 的 URL 构造逻辑
- 开发环境使用代理前缀，生产环境使用同域路径
- 移除硬编码端口，通过环境变量配置

frontend/src/flows/services/custom-service.ts

@@ -144,40 +144,31 @@ export class CustomService {
 
     // 构造 WS URL
     const base = (api.defaults.baseURL || '') as string; // 可能是 /api 或 http(s)://host/api
-    function toWsUrl(httpUrl: string) {
-      if (httpUrl.startsWith('https://')) return 'wss://' + httpUrl.slice('https://'.length);
-      if (httpUrl.startsWith('http://')) return 'ws://' + httpUrl.slice('http://'.length);
-      // 相对路径：拼 window.location
-      const origin = window.location.origin; // http(s)://host:port
-      const full = origin.replace(/^http/, 'ws') + (httpUrl.startsWith('/') ? httpUrl : '/' + httpUrl);
-      return full;
-    }
-    const path = `/flows/${id}/run/ws`;
-    // 取 token 放到查询参数（WS 握手无法自定义 Authorization 头部）
-    const token = getToken();
-
-    // 新增：WS 使用独立端口，默认 8855，可通过 VITE_WS_PORT 覆盖
-    const wsPort = (import.meta as any).env?.VITE_WS_PORT || '8855';
-    let wsBase: string;
+    // 解析出 API 的路径前缀（用于生产环境相对路径），默认 /api
+    let apiPathPrefix = '/api';
     if (base.startsWith('http://') || base.startsWith('https://')) {
       try {
         const u = new URL(base);
-        const proto = u.protocol === 'https:' ? 'wss:' : 'ws:';
-        u.protocol = proto;
-        u.port = wsPort; // 改为 WS 端口
-        wsBase = `${u.protocol}//${u.host}${u.pathname.replace(/\/$/, '')}`;
-      } catch {
-        const loc = window.location;
-        const proto = loc.protocol === 'https:' ? 'wss:' : 'ws:';
-        wsBase = `${proto}//${loc.hostname}:${wsPort}${base.startsWith('/') ? base : '/' + base}`;
-      }
-    } else {
-      const loc = window.location;
-      const proto = loc.protocol === 'https:' ? 'wss:' : 'ws:';
-      wsBase = `${proto}//${loc.hostname}:${wsPort}${base.startsWith('/') ? base : '/' + base}`;
+        apiPathPrefix = (u.pathname.replace(/\/$/, '') || '/api');
+      } catch {}
+    } else if (base.startsWith('/')) {
+      apiPathPrefix = (base.replace(/\/$/, '') || '/api');
     }
 
-    const wsUrl = wsBase + path + (token ? (wsBase.includes('?') ? `&access_token=${encodeURIComponent(token)}` : `?access_token=${encodeURIComponent(token)}`) : '');
+    const path = `/flows/${id}/run/ws`;
+    // 取 token 放到查询参数（WS 握手无法自定义 Authorization 头部）
+    const token = getToken();
+    const isDev = !!((import.meta as any).env?.DEV);
+    // 开发：走 /ws 前缀（由 Vite 代理到 8855 并 rewrite 到 /api）
+    // 生产：走同域 /api 前缀，由 Nginx/网关反代，不显式暴露端口
+    const prefix = isDev ? '/ws' : apiPathPrefix;
+    const qs = token ? `?access_token=${encodeURIComponent(token)}` : '';
+
+    // 始终构造绝对 WS URL，避免浏览器兼容性问题
+    const loc = window.location;
+    const proto = loc.protocol === 'https:' ? 'wss:' : 'ws:';
+    const origin = `${proto}//${loc.host}`; // host 里已包含端口（开发时 5173），线上通常无端口
+    const wsUrl = `${origin}${prefix}${path}${qs}`;
 
     let ws: WebSocket | null = null;
     let resolveDone: (v: RunResult | null) => void;
@@ -253,27 +244,34 @@ export class CustomService {
       return { cancel: () => {}, done: Promise.resolve<RunResult | null>(null) } as const;
     }
 
-    const base = (api.defaults.baseURL || '') as string;
-    // 参照 WS：SSE 使用独立端口，默认 8866，可通过 VITE_SSE_PORT 覆盖
-    const ssePort = (import.meta as any).env?.VITE_SSE_PORT || '8866';
-    let sseBase: string;
-    if (base.startsWith('http://') || base.startsWith('https://')) {
-      try {
-        const u = new URL(base);
-        // 协议保持与 base 一致，仅替换端口
-        u.port = ssePort;
-        sseBase = `${u.protocol}//${u.host}${u.pathname.replace(/\/$/, '')}`;
-      } catch {
+    // 在开发环境通过 Vite 代理前缀 /sse 转发到 8866（vite.config.ts 已配置 rewrite 到 /api）
+    const useSseProxy = !!((import.meta as any).env?.DEV);
+    let url: string;
+
+    if (useSseProxy) {
+      url = `/sse/flows/${id}/run/stream`;
+    } else {
+      const base = (api.defaults.baseURL || '') as string;
+      // 参照 WS：SSE 使用独立端口，默认 8866，可通过 VITE_SSE_PORT 覆盖
+      const ssePort = (import.meta as any).env?.VITE_SSE_PORT || '8866';
+      let sseBase: string;
+      if (base.startsWith('http://') || base.startsWith('https://')) {
+        try {
+          const u = new URL(base);
+          // 协议保持与 base 一致，仅替换端口
+          u.port = ssePort;
+          sseBase = `${u.protocol}//${u.host}${u.pathname.replace(/\/$/, '')}`;
+        } catch {
+          const loc = window.location;
+          sseBase = `${loc.protocol}//${loc.hostname}:${ssePort}${base.startsWith('/') ? base : '/' + base}`;
+        }
+      } else {
         const loc = window.location;
         sseBase = `${loc.protocol}//${loc.hostname}:${ssePort}${base.startsWith('/') ? base : '/' + base}`;
       }
-    } else {
-      const loc = window.location;
-      sseBase = `${loc.protocol}//${loc.hostname}:${ssePort}${base.startsWith('/') ? base : '/' + base}`;
+      url = sseBase + `/flows/${id}/run/stream`;
     }
 
-    const url = sseBase + `/flows/${id}/run/stream`;
-
     const { cancel, done } = postSSE<RunResult | null>(url, { input }, {
       onMessage: (json: any) => {
         try {