fix: 全链路追踪时间显示 — UTC→UTC+8 本地时间

- 新增 formatLocalTime() 替换 toISOString()
- 追踪面板时间显示为北京时间

Co-Authored-By: Claude <noreply@anthropic.com>

ethend/src/index.js

@@ -1304,7 +1304,7 @@ app.get('/api/trace/recent', async (req, res) => {
         const groupName = entry.group_name ? ` (${entry.group_name})` : '';
         traces.push({
           id: `msg-${ts}-${Math.random().toString(36).slice(2, 6)}`,
-          timestamp: new Date(ts).toISOString(), ts,
+          timestamp: formatLocalTime(ts), ts,
           service: 'platform-bridge',
           hop,
           label: `${icon} ${isIncoming ? '收到' : '发送'}消息 · ${entry.platform || '?'}${groupName}`,
@@ -1322,7 +1322,7 @@ app.get('/api/trace/recent', async (req, res) => {
       const ts = call.time ? new Date(call.time).getTime() : Date.now();
       traces.push({
         id: `llm-${ts}-${Math.random().toString(36).slice(2, 6)}`,
-        timestamp: new Date(ts).toISOString(), ts,
+        timestamp: formatLocalTime(ts), ts,
         service: 'ai-core', hop: 'llm_call',
         label: `🧠 LLM: ${call.model || 'unknown'}`,
         status: call.success ? 'success' : 'error',
@@ -1355,7 +1355,7 @@ app.get('/api/trace/recent', async (req, res) => {
       const ts = ev.timestamp ? new Date(ev.timestamp).getTime() : Date.now();
       traces.push({
         id: ev.id || `trace-${ts}`,
-        timestamp: new Date(ts).toISOString(), ts,
+        timestamp: formatLocalTime(ts), ts,
         service: 'ai-core',
         hop: ev.hop || 'trace',
         label: ev.label || '',
@@ -1373,7 +1373,7 @@ app.get('/api/trace/recent', async (req, res) => {
         const ts = s.last_activity ? new Date(s.last_activity).getTime() : Date.now();
         traces.push({
           id: `session-${s.session_id || ''}`,
-          timestamp: new Date(ts).toISOString(), ts,
+          timestamp: formatLocalTime(ts), ts,
           service: 'gateway', hop: 'session',
           label: `👤 会话: ${userID}`,
           status: s.state === 'streaming' ? 'running' : 'success',
@@ -1907,6 +1907,14 @@ server.listen(ETHEND_PORT, () => {
   }
 });
 
+// 时间格式化：UTC+8 本地时间
+function formatLocalTime(ts) {
+  var d = new Date(ts);
+  var pad = function(n) { return n < 10 ? '0' + n : '' + n; };
+  return d.getFullYear() + '-' + pad(d.getMonth()+1) + '-' + pad(d.getDate()) + ' ' +
+    pad(d.getHours()) + ':' + pad(d.getMinutes()) + ':' + pad(d.getSeconds());
+}
+
 // 优雅退出
 process.on('SIGINT', async () => {
   console.log('\n关闭所有服务...');