Fix admin CSS not loading and quirks mode issues

Fixed multiple issues in admin panel:

1. CSS path: modern-normalize.css → modern-normalize.min.css
   (File is actually named .min.css)

2. Icon path: assets/icon.svg → /assets/admin_favicon.svg
   (Was relative, now absolute; correct filename)

3. Navigation: /admin/list.php → /admin/
   (list.php was renamed to index.php)

4. Short PHP tags: <? → <?php
   (Better compatibility, some servers don't enable short_open_tag)

5. Quirks mode warning was due to CSS not loading, not DOCTYPE
   (DOCTYPE was already present)

Files modified:
- public/admin/inc/head.php (main fixes)
- public/admin/index.php (short tags)
- public/admin/add.php (short tags)
- public/admin/import.php (short tags)

Need to redeploy for production: just deploy

public/index.php

@@ -0,0 +1,57 @@
+<?php
+// Load configuration
+require_once __DIR__ . '/../config/bootstrap.php';
+require_once APP_ROOT . '/lib/Database.php';
+
+$pageTitle = "Liste des TFE";
+$page = isset($_GET["page"]) ? intval($_GET["page"]) : 1;
+$itemsPerPage = 10;
+
+try {
+    $db = Database::getInstance();
+    $offset = ($page - 1) * $itemsPerPage;
+    $itemsToLoad = $db->getPublishedTheses($itemsPerPage, $offset);
+    $totalItems = $db->countPublishedTheses();
+    $totalPages = ceil($totalItems / $itemsPerPage);
+} catch (Exception $e) {
+    error_log("Error loading theses: " . $e->getMessage());
+    $itemsToLoad = [];
+    $totalPages = 0;
+}
+
+include APP_ROOT . '/includes/header.php';
+?>
+
+<main>
+    <?php foreach ($itemsToLoad as $item): ?>
+        <a href="memoire.php?id=<?= $item["id"] ?>" class="card-link">
+            <div class="card">
+                <div class="card-content">
+                    <h2 class="title"><?= htmlspecialchars($item["title"]) ?></h2>
+                    <p class="authors"><?= htmlspecialchars($item["authors"]) ?></p>
+                    <p class="year"><?= htmlspecialchars($item["year"]) ?></p>
+                </div>
+            </div>
+        </a>
+    <?php endforeach; ?>
+
+    <?php if (empty($itemsToLoad)): ?>
+        <p>Aucun mémoire trouvé.</p>
+    <?php endif; ?>
+</main>
+
+<?php if ($totalPages > 1): ?>
+<nav class="pagination">
+    <?php if ($page > 1): ?>
+        <a href="?page=<?= $page - 1 ?>" class="pagination-previous">Précédent</a>
+    <?php endif; ?>
+
+    <?php if ($page < $totalPages): ?>
+        <a href="?page=<?= $page + 1 ?>" class="pagination-next">Suivant</a>
+    <?php endif; ?>
+
+    <span class="pagination-info">Page <?= $page ?> sur <?= $totalPages ?></span>
+</nav>
+<?php endif; ?>
+
+<?php include APP_ROOT . '/includes/footer.php'; ?>