chore(avatar): 更新默认头像文件格式

- 将默认头像从 gif 格式更改为 png 格式
- 优化图像加载性能
- 减少不必要的动画资源消耗

src/layouts/components/Header/components/Avatar.vue

@@ -38,7 +38,7 @@ import PasswordDialog from "./PasswordDialog.vue";
 import { getMerchantByPhone } from "@/api/modules/homeEntry";
 import { localGet, localSet } from "@/utils/index";
 import { resetRouter } from "@/routers/index";
-import defaultAvatar from "@/assets/images/avatar.gif";
+import defaultAvatar from "@/assets/images/avatar.png";
 import { localClear } from "@/utils";
 
 const router = useRouter();