feat: Initial authentication logic and UX

wp-content/themes/moonshine/app/components/auth/AuthConnexionButton.vue

@@ -0,0 +1,20 @@
+<script setup lang="ts">
+const { isLoggedIn } = useAuth();
+const attrs = computed(() => {
+  return isLoggedIn.value
+    ? {
+        label: "Déconnexion",
+        icon: "i-lucide-log-out",
+      }
+    : {
+        label: "Connexion",
+        icon: "i-lucide-log-in",
+      };
+});
+</script>
+
+<template>
+  <AuthState>
+    <UButton to="/connexion" v-bind="attrs" color="neutral" />
+  </AuthState>
+</template>