bug：修复房间号模块显示问题

src/pages/battle-room.vue

@@ -229,7 +229,11 @@ onShow(() => {
 });
 
 onLoad(async (options) => {
-  if (options.roomNumber) roomNumber.value = options.roomNumber;
+  if (options.roomNumber) {
+    roomNumber.value = options.roomNumber;
+    // 立即通知 Header 显示房号，无需等待异步 API 返回
+    uni.$emit("battle-room-info", { roomNumber: options.roomNumber });
+  }
 });
 
 onMounted(() => {