feat(assets): 将图片资源从 JPG/PNG 更新为 WebP 格式

- 将 MBTI 图标从 PNG 更改为 WebP 格式以优化加载性能
- 更新背景图片路径配置以使用 WebP 图片资源
- 移除对 sessionStorage 中图片 URL 列表的重复设置逻辑

js/config.js

@@ -18,13 +18,13 @@ const SiteConfig = {
   
   background: {
     imagePaths: [
-      "/images/bj/1.jpg",
-      "/images/bj/2.jpg",
-      "/images/bj/3.jpg",
-      "/images/bj/4.jpg",
-      "/images/bj/5.jpg",
-      "/images/bj/6.jpg",
-      "/images/bj/7.jpg"
+      "/images/bj/1.webp",
+      "/images/bj/2.webp",
+      "/images/bj/3.webp",
+      "/images/bj/4.webp",
+      "/images/bj/5.webp",
+      "/images/bj/6.webp",
+      "/images/bj/7.webp"
     ]
   },