Added supabase auth to project

This design is minimalist for now, it might be extended (at least with a basic profil page or command list)

components/ui/avatar/AvatarFallback.vue

@@ -0,0 +1,11 @@
+<script setup lang="ts">
+import { AvatarFallback, type AvatarFallbackProps } from 'radix-vue'
+
+const props = defineProps<AvatarFallbackProps>()
+</script>
+
+<template>
+  <AvatarFallback v-bind="props">
+    <slot />
+  </AvatarFallback>
+</template>