feat: Add a client-side only user selection interface

frontend/components/LoginModalAvatar.vue

@@ -0,0 +1,17 @@
+<template>
+    <button class="relative" @click="$emit('selectUser', user)">
+        <Avatar class="w-24" :user="user" />
+        <div class="absolute w-fit mx-auto bottom-0 inset-x-0">
+            <kbd class="kbd kbd-sm">{{ rank }}</kbd>
+        </div>
+    </button>
+</template>
+
+<script setup lang="ts">
+    import type { User } from '~/types/user';
+
+    const props = defineProps<{
+        user: User,
+        rank: Number,
+    }>();
+</script>