feat: licence page, admin pages editor, license types, gradient card placeholders, latest-year home view

- Feature 1: public /licence.php fetches 'licenses' page from DB, renders Markdown
- Feature 1: nav.php adds 'Licence' link with active state
- Feature 2: Database::getPage(), savePage(), getAllPages() methods
- Feature 2: bundled src/Parsedown.php (MIT, zero-dependency)
- Feature 2: apropos.php now renders 'about' page content from DB via Parsedown
- Feature 2: admin/pages.php (list) + admin/pages-edit.php (EasyMDE editor)
- Feature 2: admin/actions/page.php (auth+CSRF+validation+save)
- Feature 2: admin/head.php adds 'Pages statiques' nav link
- Feature 3: storage/schema.sql seeds 8 CC license types
- Feature 3: storage/migrations/003_seed_license_types.sql (applied to live DB)
- Feature 3: Database::getLicenseTypes() / getAllLicenseTypes()
- Feature 3: admin/add.php + formulaire.php: license_id field on add form
- Feature 3: admin/edit.php: license_id field on edit form with raw FK lookup
- Feature 3: tfe.php: shows 'Licence :' meta row when non-null
- Feature 6: main.css: .card__media--gradient styles
- Feature 6: index.php: deterministic HSL gradient placeholder cards
- Feature 6: Database::getLatestYearTheses() + getLatestPublishedYear()
- Feature 6: index.php default home = random latest-year theses with info label

public/admin/pages.php

@@ -0,0 +1,55 @@
+<?php
+require_once __DIR__ . "/../../config/bootstrap.php";
+require_once __DIR__ . '/../../src/AdminAuth.php';
+AdminAuth::requireLogin();
+
+require_once __DIR__ . '/../../src/Database.php';
+
+$pageTitle = "Pages statiques";
+
+try {
+    $db = new Database();
+    $pages = $db->getAllPages();
+} catch (Exception $e) {
+    error_log("Error loading pages: " . $e->getMessage());
+    die("Erreur lors du chargement des pages.");
+}
+
+$success = $_SESSION['success'] ?? null;
+unset($_SESSION['success']);
+?>
+<?php require_once APP_ROOT . '/templates/admin/head.php'; ?>
+
+<main class="admin-main">
+    <h1 class="admin-page-title">Pages statiques</h1>
+
+    <?php if ($success): ?>
+    <div class="admin-alert admin-alert--success">✓ <?= htmlspecialchars($success) ?></div>
+    <?php endif; ?>
+
+    <table class="admin-table">
+        <thead>
+            <tr>
+                <th>Slug</th>
+                <th>Titre</th>
+                <th>Mis à jour</th>
+                <th>Action</th>
+            </tr>
+        </thead>
+        <tbody>
+            <?php foreach ($pages as $p): ?>
+            <tr>
+                <td><code><?= htmlspecialchars($p['slug']) ?></code></td>
+                <td><?= htmlspecialchars($p['title']) ?></td>
+                <td><?= htmlspecialchars($p['updated_at'] ?? '—') ?></td>
+                <td>
+                    <a href="/admin/pages-edit.php?slug=<?= urlencode($p['slug']) ?>"
+                       class="admin-btn" style="font-size:.8rem;padding:.3rem .75rem;">Éditer</a>
+                </td>
+            </tr>
+            <?php endforeach; ?>
+        </tbody>
+    </table>
+</main>
+
+<?php require_once APP_ROOT . '/templates/admin/footer.php'; ?>