feat : recherche titre, toggle à la une, date modif, retour sources (v1.6.15)

- admin/articles : champ filter_search (titre, insensible casse) cumulable avec auteur/catégorie/statut (#85)
- admin/articles : colonne ★ avec toggle rapide featured + filtre filter_featured (#84)
- post/ : date de modification sous la date de publication si modifié après mise en ligne (#81)
- sources/ : bouton ← Retour à l'article vers post/<slug> au lieu de /edit/<uuid> (#83)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

public/index.php

@@ -2355,9 +2355,13 @@ switch ($action) {
             $filterAuthor   = trim($_GET['filter_author']   ?? '');
             $filterCategory = trim($_GET['filter_category'] ?? '');
             $filterStatus   = trim($_GET['filter_status']   ?? '');
+            $filterSearch   = trim($_GET['filter_search']   ?? '');
+            $filterFeatured = trim($_GET['filter_featured'] ?? '');
             $adminData['filter_author']   = $filterAuthor;
             $adminData['filter_category'] = $filterCategory;
             $adminData['filter_status']   = $filterStatus;
+            $adminData['filter_search']   = $filterSearch;
+            $adminData['filter_featured'] = $filterFeatured;
 
             $nowTs = time();
             if ($filterAuthor !== '') {
@@ -2373,6 +2377,12 @@ switch ($action) {
             } elseif ($filterStatus === 'preview') {
                 $allArticles = array_values(array_filter($allArticles, fn ($a) => $a['published'] && strtotime((string)($a['published_at'] ?? '')) > $nowTs));
             }
+            if ($filterSearch !== '') {
+                $allArticles = array_values(array_filter($allArticles, fn ($a) => mb_stripos($a['title'] ?? '', $filterSearch) !== false));
+            }
+            if ($filterFeatured === 'yes') {
+                $allArticles = array_values(array_filter($allArticles, fn ($a) => !empty($a['featured'])));
+            }
 
             $sortBy  = in_array($_GET['sort'] ?? '', ['title', 'published', 'updated']) ? $_GET['sort'] : 'updated';
             $sortDir = ($_GET['dir'] ?? '') === 'asc' ? 'asc' : 'desc';
@@ -2741,6 +2751,21 @@ switch ($action) {
         header('Location: /admin/smtp');
         exit;
 
+    case 'admin_toggle_featured':
+        requireAuth();
+        if (!isAdmin() || $_SERVER['REQUEST_METHOD'] !== 'POST') {
+            http_response_code(403);
+            exit;
+        }
+        $uid = trim((string)($_POST['uuid'] ?? ''));
+        $art = $uid !== '' ? $articles->getByUuid($uid) : null;
+        if ($art) {
+            $articles->setFeatured($uid, !((bool)($art['featured'] ?? false)));
+        }
+        $back = $_POST['_back'] ?? '/admin/articles';
+        header('Location: ' . $back);
+        exit;
+
     case 'admin_bulk_delete':
         requireAuth();
         if ($_SERVER['REQUEST_METHOD'] === 'POST') {