feat: 优化暗黑模式切换逻辑，添加初始化脚本

public/init_dark.js

@@ -0,0 +1,12 @@
+const isDarkMode = window.matchMedia("(prefers-color-scheme: dark)").matches;
+const darkMode = localStorage.getItem("darkMode");
+const sDarkValue =
+  darkMode === "auto"
+    ? isDarkMode
+      ? true
+      : false
+    : darkMode === "dark"
+    ? true
+    : false;
+
+document.documentElement.classList.toggle("s-dark", sDarkValue);