refactor(background): 简化背景功能为静态图片

动态背景切换功能因效果不佳暂时移除。本次重构将背景实现简化为仅支持单张静态图片

src/config/default.ts

@@ -1,5 +1,5 @@
 export const BACKGROUND = {
-  backgroundImage: "https://i.yon.li/w/682f73d97eade.png",
-  switchTime: 10, // 10 seconds
-  transition: "background-image 0.8s ease-in-out", // CSS transition for background change
+  backgroundImage: "",
+  //   switchTime: 10, // 10 seconds
+  //   transition: "background-image 0.8s ease-in-out", // CSS transition for background change
 };