Add theme selection, dark/light mode selection

app/components/ui/dropdown-menu/DropdownMenuSub.vue

@@ -0,0 +1,18 @@
+<script setup lang="ts">
+import type { DropdownMenuSubEmits, DropdownMenuSubProps } from "reka-ui"
+import {
+  DropdownMenuSub,
+  useForwardPropsEmits,
+} from "reka-ui"
+
+const props = defineProps<DropdownMenuSubProps>()
+const emits = defineEmits<DropdownMenuSubEmits>()
+
+const forwarded = useForwardPropsEmits(props, emits)
+</script>
+
+<template>
+  <DropdownMenuSub v-slot="slotProps" data-slot="dropdown-menu-sub" v-bind="forwarded">
+    <slot v-bind="slotProps" />
+  </DropdownMenuSub>
+</template>