Harden embed live refresh with reconnect backoff and poll fallback.

Document Nginx SSE proxy settings for long-lived live streams.

Co-authored-by: Cursor <cursoragent@cursor.com>

lib/common/static/instance_live.js

@@ -1,5 +1,6 @@
 /**
  * embed 壳:SSE 收到后台 tick 后拉 JSON 快照更新 DOM,切换 tab 不再重复请求 HTML.
+ * 另有可见性恢复 + SSE 断开时的轮询兜底,避免经 Nginx 几分钟后停刷.
  */
 (function (global) {
   let liveEventSource = null;
@@ -7,6 +8,8 @@
   let localLiveVersion = -1;
   let sseConnected = false;
   let refreshTimer = null;
+  let fallbackTimer = null;
+  let reconnectAttempt = 0;
 
   function isEmbedShell() {
     return document.body && document.body.getAttribute("data-embed-shell") === "1";
@@ -16,7 +19,7 @@
     if (global.InstanceEmbed && typeof global.InstanceEmbed.getTab === "function") {
       return global.InstanceEmbed.getTab();
     }
-    return document.body.getAttribute("data-page") || "trade";
+    return document.body.getAttribute("data-page") || "options";
   }
 
   function refreshTabData(tab, opts) {
@@ -30,7 +33,9 @@
     if (tab === "options" && global.OptionsPanelLive && typeof global.OptionsPanelLive.refreshSoft === "function") {
       global.OptionsPanelLive.refreshSoft(options);
     }
-    // 数据看板自有 SSE + 快照,不跟 embed live tick 重拉.
+    if (tab === "hedge_plan" && global.HedgePlanLive && typeof global.HedgePlanLive.refreshSoft === "function") {
+      global.HedgePlanLive.refreshSoft(options);
+    }
   }
 
   function scheduleRefresh(opts) {
@@ -76,23 +81,42 @@
     liveEventSource.addEventListener("live", function (ev) {
       try {
         onLiveEvent(JSON.parse(ev.data || "{}"));
+        reconnectAttempt = 0;
       } catch (_) {}
     });
     liveEventSource.onopen = function () {
       sseConnected = true;
+      reconnectAttempt = 0;
     };
     liveEventSource.onerror = function () {
       sseConnected = false;
       closeLiveStream();
+      reconnectAttempt += 1;
+      var delay = Math.min(30000, 3000 + reconnectAttempt * 2000);
       liveReconnectTimer = setTimeout(function () {
         connectLiveStream();
-      }, 8000);
+      }, delay);
     };
   }
 
+  function ensureFallbackPoll() {
+    if (fallbackTimer) return;
+    // SSE 正常时也做低频兜底;断开时依赖它持续刷新
+    fallbackTimer = setInterval(function () {
+      if (document.hidden) return;
+      scheduleRefresh({ force: !sseConnected });
+    }, sseConnected ? 20000 : 8000);
+  }
+
   function startLive() {
     if (!isEmbedShell()) return;
     connectLiveStream();
+    ensureFallbackPoll();
+    document.addEventListener("visibilitychange", function () {
+      if (document.hidden) return;
+      if (!sseConnected) connectLiveStream();
+      scheduleRefresh({ force: true });
+    });
   }
 
   global.InstanceLive = {