fix(uploads): reclaim abandoned front-submit attachments

Mark new regular and chunked uploads as pending and claim persisted article references, including partial saves and large reference sets. Protect associated media from cleanup and add upload lifecycle regression coverage.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/Core/FrontSubmit.php

@@ -38,8 +38,6 @@ class FrontSubmit {
         add_action('wp_ajax_nopriv_aksrt_submit_post', [$this, 'ajax_submit_post']);
 
         add_action('rest_api_init', [$this, 'register_rest_routes']);
-        add_action('aksrt_new_add_posts', [$this, 'sync_post_attachments']);
-        add_action('aksrt_new_edit_posts', [$this, 'sync_post_attachments']);
 
         add_filter('body_class', [$this, 'body_class']);
         add_filter('wp_robots', [$this, 'robots_noindex']);
@@ -231,6 +229,7 @@ class FrontSubmit {
             return new \WP_Error('aksrt_upload_failed', __('上传后无法读取文件。', 'aksrt'), ['status' => 500]);
         }
 
+        \AKSRT\Attachment\PendingUploads::mark($attachment_id);
         $attachment['success'] = true;
         return new \WP_REST_Response($attachment, 201);
     }