Move brainblast vue app to ui repository

ui/src/components/BrainBlastBar.vue

@@ -0,0 +1,27 @@
+<template>
+  <v-app-bar :elevation="5">
+    <RouterMenu />
+    <v-app-bar-title>Brain Blast</v-app-bar-title>
+
+    <template v-slot:append>
+      <v-btn icon @click="toggleTheme">
+        <v-icon>{{ darkTheme ? 'mdi-white-balance-sunny' : 'mdi-moon-waning-crescent' }}</v-icon>
+      </v-btn>
+    </template>
+  </v-app-bar>
+</template>
+
+<script setup>
+  import { ref } from 'vue'
+  import { useTheme } from 'vuetify'
+  import RouterMenu from '@/components/RouterMenu.vue'
+
+  const theme = useTheme()
+  const darkTheme = ref(true)
+
+  function toggleTheme() {
+    darkTheme.value = !darkTheme.value
+    theme.global.name.value = theme.global.current.value.dark ? 'light' : 'dark'
+  }
+
+</script>