fix: address code review findings for bookmark feature (H1–L5)

Fix broken tests (H1), align interface signatures with implementations (H3),
remove dead code (H4), add missing input guard (M1), replace raw $_SESSION
access with SessionStoreInterface (M2), sync update script schema (M4),
use shared getAppBase utility (L2), document fragment stripping (L3),
and apply app- CSS class prefix convention (L5).

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

lib/Repository/User/BookmarkGroupRepository.php

@@ -3,50 +3,31 @@
 namespace MintyPHP\Repository\User;
 
 use MintyPHP\DB;
+use MintyPHP\Repository\Support\RepoQuery;
+use MintyPHP\Repository\Support\RepositoryArrayHelper;
 
 class BookmarkGroupRepository implements BookmarkGroupRepositoryInterface
 {
     private function unwrapList(mixed $rows): array
     {
-        if (!is_array($rows)) {
-            return [];
-        }
-        $list = [];
-        foreach ($rows as $row) {
-            $data = $row['user_bookmark_groups'] ?? $row;
-            if (is_array($data)) {
-                $list[] = $data;
-            }
-        }
-        return $list;
+        return RepositoryArrayHelper::unwrapList($rows, 'user_bookmark_groups');
     }
 
-    public function listByUser(int $userId): array
+    public function listByUser(int $userId, array $options = []): array
     {
         if ($userId <= 0) {
             return [];
         }
+        [$limit, $offset] = RepoQuery::sanitizeLimitOffset($options, 100, 1, 100);
         $rows = DB::select(
-            'select id, user_id, name, icon, sort_order, created, modified from user_bookmark_groups where user_id = ? order by sort_order, id',
-            (string) $userId
+            'select id, user_id, name, icon, sort_order, created, modified from user_bookmark_groups where user_id = ? order by sort_order, id limit ? offset ?',
+            (string) $userId,
+            (string) $limit,
+            (string) $offset
         );
         return $this->unwrapList($rows);
     }
 
-    public function nextGroupSortOrder(int $userId): int
-    {
-        if ($userId <= 0) {
-            return 1;
-        }
-
-        $max = DB::selectValue(
-            'select COALESCE(max(sort_order), 0) from user_bookmark_groups where user_id = ?',
-            (string) $userId
-        );
-
-        return max(1, ((int) $max) + 1);
-    }
-
     public function countByUser(int $userId): int
     {
         if ($userId <= 0) {