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/biome.json

@@ -0,0 +1,16 @@
+{
+  "$schema": "../../node_modules/@biomejs/biome/configuration_schema.json",
+  "extends": "//",
+  "css": {
+    "parser": {
+      "tailwindDirectives": true
+    }
+  },
+  "linter": {
+    "rules": {
+      "nursery": {
+        "useSortedClasses": "warn"
+      }
+    }
+  }
+}