关键位现价改与顶栏同源公开行情，前端无价时回退 nav tickers。

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

lib/common/static/symbol_live_price.js

@@ -1,5 +1,6 @@
 /**
  * 表单币种输入:防抖 + 定时刷新,展示交易所最新价(/api/order_defaults).
+ * BTC/ETH 在 order_defaults 无价时回退 /api/nav_spot_tickers(与顶栏同源).
  */
 (function (global) {
   "use strict";
@@ -65,6 +66,41 @@
     el.title = "交易所最新价(约 " + pollMs() / 1000 + "s 刷新)";
   }
 
+  function symbolBase(sym) {
+    return String(sym || "")
+      .trim()
+      .toUpperCase()
+      .split("/")[0]
+      .split(":")[0];
+  }
+
+  function fetchNavLast(sym) {
+    const base = symbolBase(sym);
+    if (base !== "BTC" && base !== "ETH") {
+      return Promise.resolve(null);
+    }
+    return fetch("/api/nav_spot_tickers")
+      .then(function (r) {
+        return r.json().catch(function () {
+          return null;
+        });
+      })
+      .then(function (d) {
+        if (!d || !d.ok || !Array.isArray(d.tickers)) return null;
+        for (let i = 0; i < d.tickers.length; i++) {
+          const t = d.tickers[i] || {};
+          if (String(t.base || "").toUpperCase() === base && t.last != null) {
+            const n = Number(t.last);
+            return Number.isFinite(n) && n > 0 ? n : null;
+          }
+        }
+        return null;
+      })
+      .catch(function () {
+        return null;
+      });
+  }
+
   function bindOne(el) {
     if (!el || bound.has(el)) return;
     bound.add(el);
@@ -87,6 +123,15 @@
       pollTimer = setInterval(refresh, pollMs());
     }
 
+    function applyPrice(sym, px) {
+      if (px === null || typeof px === "undefined") {
+        paint(el, sym, null, "无法读取交易所价格");
+        return;
+      }
+      paint(el, sym, px, "");
+      if (!pollTimer) startPoll();
+    }
+
     function refresh() {
       const symEl = $(symId);
       const sym = symbolValue(symEl);
@@ -116,21 +161,35 @@
           el.classList.remove("symbol-live-price--loading");
           const data = res.data || {};
           if (res.status >= 400 || !data || !data.ok) {
-            paint(el, sym, null, (data && data.msg) || "读取失败");
-            return;
+            return fetchNavLast(sym).then(function (navPx) {
+              if (seq !== fetchSeq) return;
+              if (navPx != null) {
+                applyPrice(sym, navPx);
+                return;
+              }
+              paint(el, sym, null, (data && data.msg) || "读取失败");
+            });
           }
           const px = data.last_price != null ? data.last_price : data.price;
           if (px === null || typeof px === "undefined") {
-            paint(el, data.symbol || sym, null, "无法读取交易所价格");
-            return;
+            return fetchNavLast(sym).then(function (navPx) {
+              if (seq !== fetchSeq) return;
+              applyPrice(data.symbol || sym, navPx);
+            });
           }
-          paint(el, data.symbol || sym, px, "");
-          if (!pollTimer) startPoll();
+          applyPrice(data.symbol || sym, px);
         })
         .catch(function () {
           if (seq !== fetchSeq) return;
           el.classList.remove("symbol-live-price--loading");
-          paint(el, sym, null, "网络错误");
+          fetchNavLast(sym).then(function (navPx) {
+            if (seq !== fetchSeq) return;
+            if (navPx != null) {
+              applyPrice(sym, navPx);
+              return;
+            }
+            paint(el, sym, null, "网络错误");
+          });
         });
     }