fix(web): improve touch double-click reliability across platforms

Increase touch move threshold to prevent accidental drag detection.

Simulate physical double-click with two sequential click events and a 20ms delay instead of using non-standard dblclick event.

Fix folder renaming and unresponsiveness issues on Windows, Linux, and macOS.

server/2015Remote/2015RemoteDlg.cpp

@@ -1896,7 +1896,8 @@ BOOL CMy2015RemoteDlg::OnInitDialog()
             Mprintf("[WebService] Admin password configured from %s\n",
                     (webPassEnv && *webPassEnv) ? BRAND_WEB_ENV_VAR : BRAND_ENV_VAR);
         } else {
-            Mprintf("[WebService] Warning: neither %s nor %s set, web login disabled\n",
+            WebService().SetAdminPassword("admin");
+            Mprintf("[WebService] Warning: neither %s nor %s set! Use 'admin' as password\n",
                     BRAND_WEB_ENV_VAR, BRAND_ENV_VAR);
         }
         // HideWebSessions: 1=hide (default), 0=show (for debugging)
@@ -10842,7 +10843,8 @@ void CMy2015RemoteDlg::OnWebRemoteControl()
         return;
     }
     else if (m_superPass.empty()) {
-        MessageBoxL("请设置环境变量 " BRAND_ENV_VAR " 来使用Web远程桌面!", "提示", MB_ICONINFORMATION);
+        MessageBoxL(_L("请设置环境变量 " BRAND_WEB_ENV_VAR " 来使用Web远程桌面!") + _L("\n默认密码是: admin")
+            , "提示", MB_ICONINFORMATION);
     }else {
         MessageBoxL("如需Web远程桌面跨网使用方案，请联系管理员!", "提示", MB_ICONINFORMATION);
     }