fix(HEL-488): 盘中日K补上今天实时变化的一根

悬浮窗和详情页在 Tushare rt_k / iFinD 不可用时，改用免费实时行情或当日分时生成今日K，收盘后正式日K就绪再无缝替换。

Co-authored-by: Cursor <cursoragent@cursor.com>
Co-authored-by: multica-agent <github@multica.ai>

frontend/pages/market/preview.js

@@ -367,7 +367,11 @@ function selectStockPreviewChart(chart) {
     }
   } else if ((payload.prices || []).length) {
     setText("stockPreviewDate", payload.meta?.trade_date || "最新行情");
-    setText("stockPreviewSource", `日 K 行情 · ${payload.prices.length} 个交易日`);
+    const notice = String(payload.meta?.notice || "").trim();
+    setText(
+      "stockPreviewSource",
+      notice ? `日 K 行情 · ${payload.prices.length} 个交易日 · ${notice}` : `日 K 行情 · ${payload.prices.length} 个交易日`,
+    );
     drawDailyPreviewChart(payload.prices);
   } else {
     setText("stockPreviewDate", payload.meta?.trade_date || "最新行情");

frontend/pages/market/stock-detail.js

@@ -52,7 +52,11 @@ async function openStock(code, fallback = null) {
     renderStockNotes(payload.notes || []);
     updateWatchButton();
     if (state.stockDetailChartMode === "daily") {
-      setText("chartSource", `日 K 行情 · ${payload.prices.length} 个交易日`);
+      const notice = String(payload.meta?.notice || "").trim();
+      setText(
+        "chartSource",
+        notice ? `日 K 行情 · ${payload.prices.length} 个交易日 · ${notice}` : `日 K 行情 · ${payload.prices.length} 个交易日`,
+      );
       requestAnimationFrame(() => drawPriceChart(payload.prices || []));
     }
   } catch (error) {
@@ -69,7 +73,13 @@ async function selectStockDetailChart(mode) {
   syncDetailChartButtons("stock", selected);
   if (selected === "daily") {
     const prices = state.stockDetail?.prices || [];
-    setText("chartSource", prices.length ? `日 K 行情 · ${prices.length} 个交易日` : "正在加载行情");
+    const notice = String(state.stockDetail?.meta?.notice || "").trim();
+    setText(
+      "chartSource",
+      prices.length
+        ? (notice ? `日 K 行情 · ${prices.length} 个交易日 · ${notice}` : `日 K 行情 · ${prices.length} 个交易日`)
+        : "正在加载行情",
+    );
     if (prices.length) requestAnimationFrame(() => drawPriceChart(prices));
     else clearPriceChart("正在加载日 K 数据");
     return;