Lock Android portrait via fullscreen then orientation.lock.

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

frontend/index.html

@@ -4,7 +4,7 @@
     <meta charset="UTF-8" />
     <meta
       name="viewport"
-      content="width=device-width, initial-scale=1.0, viewport-fit=cover"
+      content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no, viewport-fit=cover"
     />
     <meta name="theme-color" content="#0b0e11" />
     <meta name="color-scheme" content="dark" />
@@ -13,6 +13,13 @@
     <meta name="apple-mobile-web-app-status-bar-style" content="black-translucent" />
     <meta name="apple-mobile-web-app-title" content="比特骆驼" />
     <meta name="application-name" content="比特骆驼" />
+    <!-- 安卓 WebView / X5 / UC：声明竖屏（Chrome 仍需 JS 全屏+lock 或安装 PWA） -->
+    <meta name="screen-orientation" content="portrait" />
+    <meta name="x5-orientation" content="portrait" />
+    <meta name="x5-page-mode" content="app" />
+    <meta name="browsermode" content="application" />
+    <meta name="full-screen" content="yes" />
+    <meta name="x5-fullscreen" content="true" />
     <meta
       name="description"
       content="比特骆驼自动化对冲系统：ETH 永续+期权对冲监控与策略控制台，支持电脑与平板安装为独立应用。"