feat(flow): 新增流式执行模式与SSE支持

新增流式执行模式，通过SSE实时推送节点执行事件与日志
重构HTTP执行器与中间件，提取通用HTTP客户端组件
优化前端测试面板，支持流式模式切换与实时日志展示
更新依赖版本并修复密码哈希的随机数生成器问题
修复前端节点类型映射问题，确保Code节点表单可用

frontend/vite.config.ts

@@ -8,7 +8,7 @@ export default defineConfig(({ mode }) => {
   const env = loadEnv(mode, '.', '')
   const port = Number(env.VITE_PORT || 5173)
   const open = String(env.VITE_OPEN ?? 'true').toLowerCase() === 'true' || env.VITE_OPEN === '1'
-  const proxyTarget = env.VITE_ADMIN_PROXY_PATH || 'http://127.0.0.1:8080'
+  const proxyTarget = env.VITE_ADMIN_PROXY_PATH || 'http://127.0.0.1:9898'
 
   return {
     plugins: [
@@ -30,7 +30,50 @@ export default defineConfig(({ mode }) => {
       proxy: {
         '/api': {
           target: proxyTarget,
-          changeOrigin: true
+          changeOrigin: true,
+          // 为 SSE 透传加固：禁用超时并保持连接
+          proxyTimeout: 0,
+          timeout: 0,
+          headers: { 'Connection': 'keep-alive' },
+          // 关键：在 dev 代理层面禁止缓冲/缓存，强制以 chunk 方式向浏览器侧回传，避免一次性聚合
+          configure: (proxy: any) => {
+            // 移除 Accept-Encoding，避免后端压缩导致中间件缓冲
+            proxy.on('proxyReq', (proxyReq: any, req: any) => {
+              const url: string = req?.url || ''
+              if (url.includes('/run/stream')) {
+                try {
+                  if (typeof proxyReq.removeHeader === 'function') proxyReq.removeHeader('accept-encoding')
+                  proxyReq.setHeader('accept', 'text/event-stream')
+                  proxyReq.setHeader('connection', 'keep-alive')
+                } catch {}
+              }
+            })
+
+            proxy.on('proxyRes', (proxyRes: any, req: any, res: any) => {
+              const url: string = req?.url || ''
+              const ct: string = String(proxyRes.headers?.['content-type'] || '')
+              const isSse = url.includes('/run/stream') || ct.includes('text/event-stream')
+              if (!isSse) return
+              try {
+                // 直接改写后端返回头，确保为 SSE 且无长度/压缩
+                proxyRes.headers['content-type'] = 'text/event-stream; charset=utf-8'
+                proxyRes.headers['cache-control'] = 'no-cache'
+                proxyRes.headers['pragma'] = 'no-cache'
+                proxyRes.headers['x-accel-buffering'] = 'no'
+                delete proxyRes.headers['content-length']
+                delete proxyRes.headers['content-encoding']
+
+                // 同步确保 devServer 给浏览器的头一致，并尽早发送
+                res.setHeader('Content-Type', 'text/event-stream; charset=utf-8')
+                res.setHeader('Cache-Control', 'no-cache')
+                res.setHeader('Pragma', 'no-cache')
+                res.setHeader('X-Accel-Buffering', 'no')
+                if (typeof res.removeHeader === 'function') res.removeHeader('Content-Length')
+                if (typeof res.removeHeader === 'function') res.removeHeader('Content-Encoding')
+                if (typeof res.flushHeaders === 'function') res.flushHeaders()
+              } catch {}
+            })
+          }
         }
       }
     }