Add missing quiz/nav.html.twig and test for template reference integrity (#166)

Adds the previously uncommitted quiz nav partial that broke main, and
introduces TemplateReferencesTest which scans all Twig templates for
extends/include/embed references and asserts each target file exists —
preventing this class of missing-template mistake from reaching CI undetected.

templates/quiz/nav.html.twig

@@ -0,0 +1,16 @@
+{% if is_granted('IS_AUTHENTICATED') or app.current_route() == 'tvdt_quiz_select_season' %}
+    <div class="quiz-topbar">
+        {% if is_granted('IS_AUTHENTICATED') %}
+            <a href="{{ path('tvdt_backoffice_index') }}" class="btn btn-outline-secondary btn-sm">
+                {{ 'Backoffice'|trans }}
+            </a>
+            <a href="{{ path('tvdt_login_logout') }}" class="btn btn-outline-secondary btn-sm">
+                {{ 'Logout'|trans }}
+            </a>
+        {% else %}
+            <a href="{{ path('tvdt_backoffice_index') }}" class="btn btn-outline-secondary btn-sm">
+                {{ 'Manage Quiz'|trans }}
+            </a>
+        {% endif %}
+    </div>
+{% endif %}

tests/Twig/TemplateReferencesTest.php

@@ -0,0 +1,63 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Tvdt\Tests\Twig;
+
+use PHPUnit\Framework\Assert;
+use PHPUnit\Framework\Attributes\DataProvider;
+use PHPUnit\Framework\TestCase;
+
+use function Safe\file_get_contents;
+use function Safe\preg_match_all;
+
+final class TemplateReferencesTest extends TestCase
+{
+    private static string $templatesDir;
+
+    public static function setUpBeforeClass(): void
+    {
+        self::$templatesDir = \dirname(__DIR__, 2).'/templates';
+    }
+
+    /** @return iterable<string, array{string, string}> */
+    public static function templateReferenceProvider(): iterable
+    {
+        $templatesDir = \dirname(__DIR__, 2).'/templates';
+        $iterator = new \RecursiveIteratorIterator(
+            new \RecursiveDirectoryIterator($templatesDir, \RecursiveDirectoryIterator::SKIP_DOTS),
+        );
+
+        foreach ($iterator as $file) {
+            Assert::assertInstanceOf(\SplFileInfo::class, $file);
+            if ('twig' !== $file->getExtension()) {
+                continue;
+            }
+
+            $content = file_get_contents($file->getPathname());
+            $sourceFile = str_replace($templatesDir.'/', '', $file->getPathname());
+
+            // Match extends, include(), and embed tags — capture the quoted template name
+            preg_match_all(
+                '/(?:extends|include|embed)\s*\(?[\'"]([^\'"]+)[\'"]\)?/',
+                $content,
+                $matches,
+            );
+
+            foreach ($matches[1] as $referencedTemplate) {
+                yield \sprintf('%s → %s', $sourceFile, $referencedTemplate) => [$sourceFile, $referencedTemplate];
+            }
+        }
+    }
+
+    #[DataProvider('templateReferenceProvider')]
+    public function testReferencedTemplateExists(string $sourceFile, string $referencedTemplate): void
+    {
+        $absolutePath = self::$templatesDir.'/'.$referencedTemplate;
+
+        $this->assertFileExists(
+            $absolutePath,
+            \sprintf("Template '%s' references '%s' which does not exist at '%s'.", $sourceFile, $referencedTemplate, $absolutePath),
+        );
+    }
+}