feat: 添加直播房间页面及相关样式和功能

- 新增直播房间页面，支持竖屏直播模式
- 实现直播播放器和消息展示功能
- 增加购物车按钮和商品推荐展示
- 更新样式以适应新页面布局
- 移除不再使用的 MQTT 相关文件和 API 调用

pages/promotion/live/utils/liveSetting.js

@@ -0,0 +1,41 @@
+import { getLiveRoomById } from "@/api/live.js";
+
+const cachedSettings = {};
+const fetchingPromises = {};
+
+export function seedLiveSetting(liveId, setting) {
+  if (liveId && setting) {
+    cachedSettings[liveId] = setting;
+  }
+}
+
+export async function fetchLiveSetting(liveId, force = false) {
+  if (!liveId) return null;
+  if (!force && cachedSettings[liveId]) return cachedSettings[liveId];
+  if (!force && fetchingPromises[liveId]) return fetchingPromises[liveId];
+
+  fetchingPromises[liveId] = (async () => {
+    try {
+      const res = await getLiveRoomById(liveId);
+      if (res.data?.success && res.data?.result) {
+        cachedSettings[liveId] = res.data.result;
+        return cachedSettings[liveId];
+      }
+      console.warn("获取直播配置失败", res.data);
+      return null;
+    } catch (error) {
+      console.error("获取直播配置异常:", error);
+      return null;
+    } finally {
+      fetchingPromises[liveId] = null;
+    }
+  })();
+
+  return fetchingPromises[liveId];
+}
+
+export function resolveSdkAppId(setting) {
+  if (!setting?.imSdkAppid) return 0;
+  const id = Number(setting.imSdkAppid);
+  return Number.isNaN(id) ? 0 : id;
+}