feat: mobile-first web client (login, lists, add task)

app/pages/auth/callback.vue

@@ -0,0 +1,26 @@
+<script setup lang="ts">
+// The Zitadel client processes the OIDC redirect during init(); once authenticated,
+// move back to the app root.
+const { auth } = useAuth();
+watchEffect(() => {
+  if (!auth.isLoading.value && auth.isAuthenticated.value) {
+    navigateTo("/", { replace: true });
+  }
+});
+</script>
+
+<template>
+  <main class="callback">
+    <p>Signing you in…</p>
+  </main>
+</template>
+
+<style scoped>
+.callback {
+  min-height: 100dvh;
+  display: grid;
+  place-items: center;
+  color: #6b7280;
+  font: 500 1rem/1.4 system-ui, sans-serif;
+}
+</style>