refactor(device): 移除设备卡片未使用的离线样式类

iconOffline 在引入产品图后实际未生效（产品图在 card 父级判断离线条带
处理），删除 SCSS 类与 cardTop 上对应的拼接 className

src/pages/device/index.module.scss

@@ -219,22 +219,16 @@
   box-shadow: 0 6px 16px rgba(44, 203, 152, 0.25);
 }
 
-.iconOffline { background: $color-bg-disabled; }
-
 .iconText {
   font-size: 36px;
   color: #ffffff;
 }
 
-.iconOffline .iconText { color: $color-text-tertiary; }
-
 .iconImg {
   width: 80px;
   height: 80px;
 }
 
-.iconOffline .iconImg { opacity: 0.5; }
-
 .name {
   max-width: 100%;
   font-size: 28px;

src/pages/device/index.tsx

@@ -239,7 +239,7 @@ export default function DeviceList() {
           {deviceList.map((device) => (
             <View key={device.installId} className={styles.card}>
               <View className={styles.cardTop} onClick={() => goDetail(device)}>
-                <View className={`${styles.icon} ${!device.onlineStatus ? styles.iconOffline : ''}`}>
+                <View className={styles.icon}>
                   {(() => {
                     const src = pickDeviceIcon(device)
                     return src ? (