chore: remove unused example assets (fixes #2)

Delete hello_controller.js and Hello.jsx, which are Symfony/UX
boilerplate files not referenced anywhere in the project.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

assets/controllers/hello_controller.js

@@ -1,16 +0,0 @@
-import { Controller } from '@hotwired/stimulus';
-
-/*
- * This is an example Stimulus controller!
- *
- * Any element with a data-controller="hello" attribute will cause
- * this controller to be executed. The name "hello" comes from the filename:
- * hello_controller.js -> "hello"
- *
- * Delete this file or adapt it for your use!
- */
-export default class extends Controller {
-    connect() {
-        this.element.textContent = 'Hello Stimulus! Edit me in assets/controllers/hello_controller.js';
-    }
-}

assets/react/controllers/Hello.jsx

@@ -1,5 +0,0 @@
-import React from 'react';
-
-export default function (props) {
-    return <div>Hello {props.fullName}</div>;
-}