Add roll leg avg/TP profit display and reduce instance nav flicker

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

static/instance_theme.js

@@ -329,19 +329,29 @@
     }
   }
 
-  /** 中控 iframe 内：拦截顶栏导航，fetch 后 document.write 原地换页，避免 iframe 卸载白屏 */
-  function initHubEmbedInFrameNav() {
-    if (!isHubLinked()) return;
+  /** 顶栏软导航：fetch + document.write 换页，避免整页卸载白屏（实例 standalone / 中控 iframe 均启用） */
+  function injectNavTransitionGuard(html, theme) {
+    const t = normalize(theme || get());
+    const bg = META[t];
+    const guard = `<style id="inst-nav-guard">html,body{background:${bg}!important;color-scheme:${t};}</style>`;
+    if (html.includes("</head>")) {
+      return html.replace("</head>", `${guard}</head>`);
+    }
+    return guard + html;
+  }
 
+  function initInstanceTopNavSoft() {
     let navToken = 0;
 
     function isSoftNavLink(a) {
       if (!a || !a.getAttribute) return false;
+      if (a.hasAttribute("download") || a.target === "_blank") return false;
       return !!a.closest(".top-nav, .strategy-subnav");
     }
 
     async function navigateInFrame(href, opts) {
       const token = ++navToken;
+      const themeNow = get();
       try {
         const r = await fetch(href, { credentials: "same-origin" });
         if (token !== navToken) return;
@@ -349,7 +359,7 @@
           location.href = href;
           return;
         }
-        const html = await r.text();
+        const html = injectNavTransitionGuard(await r.text(), themeNow);
         if (token !== navToken) return;
         let path = href;
         try {
@@ -398,13 +408,13 @@
     if (isHubLinked()) {
       apply(get(), { skipStore: true });
       window.addEventListener("message", (ev) => initFromHubMessage(ev.data));
-      initHubEmbedInFrameNav();
       try {
         window.parent.postMessage({ type: "instance-theme-ready" }, "*");
       } catch (_) {}
     } else {
       apply(getStandalone());
     }
+    initInstanceTopNavSoft();
 
     function observeDynamicLists() {
       ["journal-list", "review-list"].forEach((id) => {