feat: add registration page with form validation

templates/security/register.html.twig

@@ -0,0 +1,19 @@
+{% extends 'base.html.twig' %}
+
+{% block title %}Register{% endblock %}
+
+{% block body %}
+<div class="auth-container">
+    <h1>Register</h1>
+
+    {{ form_start(registrationForm) }}
+        {{ form_row(registrationForm.email) }}
+        {{ form_row(registrationForm.plainPassword.first) }}
+        {{ form_row(registrationForm.plainPassword.second) }}
+
+        <button type="submit">Create account</button>
+    {{ form_end(registrationForm) }}
+
+    <p class="auth-link">Already have an account? <a href="{{ path('app_login') }}">Log in</a></p>
+</div>
+{% endblock %}