chore: alinhar projeto às regras do agent

src/playground/ola_mundo.playground.vue

@@ -0,0 +1,34 @@
+<template>
+  <section class="stack">
+    <h2>EliOlaMundo</h2>
+    <p class="muted">
+      Demo integrada (útil para smoke-test visual). Para testes específicos,
+      prefira os playgrounds de <code>EliBotao</code>, <code>EliInput</code> e
+      <code>EliBadge</code>.
+    </p>
+
+    <EliOlaMundo />
+  </section>
+</template>
+
+<script lang="ts">
+import { defineComponent } from "vue";
+import { EliOlaMundo } from "@/componentes/ola_mundo";
+
+export default defineComponent({
+  name: "OlaMundoPlayground",
+  components: { EliOlaMundo },
+});
+</script>
+
+<style scoped>
+.stack {
+  display: grid;
+  gap: 12px;
+}
+
+.muted {
+  opacity: 0.75;
+  margin: 0;
+}
+</style>