chore: 清理废弃的用户端答题流程代码并优化SCSS导入

移除废弃的`user copy`目录及其所有相关文件，包括组件、类型定义、模拟数据和图片
在vite配置中全局导入SCSS变量，移除各组件中冗余的`@import`语句
更新TypeScript配置以包含build目录，并优化SCSS颜色函数的使用

apps/admin/vite.config.ts

@@ -23,7 +23,7 @@ export default defineConfig((configEnv) => {
       preprocessorOptions: {
         scss: {
           api: 'modern-compiler',
-          additionalData: `@use "@/styles/scss/global.scss" as *;`,
+          additionalData: `@use "@/styles/scss/variables.scss" as *; @use "@/styles/scss/global.scss" as *;`,
         },
       },
     },