Add application source code, configs and assets

- Controllers, Entity, Repository, Services, Twig extensions
- Templates (account, emails, home, legal, security, unsubscribe)
- Symfony config updates (bundles, security, framework, services)
- Vite + Bun setup with PostCSS
- Caddy config, CLAUDE.md, README
- Update .gitignore (node_modules, .idea, cert)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

templates/unsubscribe/confirmed.html.twig

@@ -0,0 +1,12 @@
+{% extends 'base.html.twig' %}
+
+{% block title %}Désinscription confirmée - E-Cosplay Ticket{% endblock %}
+
+{% block body %}
+    <main class="min-h-screen flex items-center justify-center bg-zinc-100">
+        <div class="bg-white rounded-xl shadow p-8 max-w-md w-full text-center">
+            <h1 class="text-2xl font-bold mb-4">Désinscription confirmée</h1>
+            <p class="text-zinc-600">L'adresse <strong>{{ email }}</strong> ne recevra plus nos emails.</p>
+        </div>
+    </main>
+{% endblock %}