Revert "chore: remove vueuse"

This reverts commit ccc82f5e0e.

src/index.ts

@@ -1,5 +1,5 @@
 import { resolve, join } from 'pathe'
-import { defineNuxtModule, installModule } from '@nuxt/kit'
+import { defineNuxtModule, installModule, addPlugin, resolveModule } from '@nuxt/kit'
 import { colors } from '@unocss/preset-uno'
 import type { UnocssNuxtOptions } from '@unocss/nuxt'
 
@@ -95,8 +95,11 @@ export default defineNuxtModule({
 
     await installModule(nuxt, { src: '@unocss/nuxt', options })
 
+    const runtimeDir = resolve(__dirname, 'runtime')
     const componentsDir = resolve(__dirname, 'components')
 
+    addPlugin(resolveModule('./plugin', { paths: runtimeDir }), { append: true })
+
     nuxt.hook('components:dirs', (dirs) => {
       dirs.push({
         path: join(componentsDir, 'elements'),

src/runtime/plugin.ts

@@ -0,0 +1,6 @@
+import { useDark } from '@vueuse/core'
+import { defineNuxtPlugin } from '#app'
+
+export default defineNuxtPlugin(() => {
+  useDark()
+})