feat: 为 desktop/server 添加 Tailwind CSS 支持和 Biome 集成

- desktop renderer 接入 @tailwindcss/vite，loading 页面改用 Tailwind 类
- 两个 app 添加 biome.json 继承配置：tailwindDirectives + useSortedClasses

apps/desktop/electron.vite.config.ts

@@ -1,7 +1,10 @@
+import tailwindcss from '@tailwindcss/vite'
 import { defineConfig } from 'electron-vite'
 
 export default defineConfig({
   main: {},
   preload: {},
-  renderer: {},
+  renderer: {
+    plugins: [tailwindcss()],
+  },
 })