feat: add a dev-only login and seed command

templates/dev/login.html.twig

@@ -0,0 +1,36 @@
+{% extends 'base.html.twig' %}
+
+{% block title %}Anmelden · ephub{% endblock %}
+
+{% block body %}
+    <div class="min-h-screen flex items-center justify-center px-4">
+        <div class="w-full max-w-md">
+            <img class="h-8 w-auto mx-auto mb-8" src="{{ asset('images/logo_ep.svg') }}" alt="ephub">
+
+            <div class="rounded-md border border-amber-300 bg-amber-50 px-4 py-3 text-sm mb-6">
+                <strong>Nur für die Entwicklung.</strong>
+                Die echte Anmeldung läuft über myep (OAuth2) und wartet auf die Client-Registrierung dort.
+            </div>
+
+            {% if users is empty %}
+                <p class="text-sm">
+                    Keine Benutzer vorhanden. <code class="font-mono">bin/console app:seed</code> ausführen.
+                </p>
+            {% else %}
+                <form method="post" class="space-y-2">
+                    {% for user in users %}
+                        <button type="submit" name="user" value="{{ user.id }}"
+                                class="w-full text-left rounded-md border border-gray-200 px-4 py-3 hover:bg-gray-50">
+                            <span class="block font-semibold">{{ user.name }}</span>
+                            <span class="block text-sm text-gray-500">{{ user.email }}</span>
+                        </button>
+                    {% endfor %}
+                </form>
+            {% endif %}
+
+            <div class="fixed bottom-4 right-4 z-50 space-y-2">
+                {% include '_partials/_flashes.html.twig' %}
+            </div>
+        </div>
+    </div>
+{% endblock %}