refactor(phone-image): Wave 2 - form, controller, JS engine, API updates

T3: Add cover_text textarea to post edit form

T4: Update Post controller - content copy + cover_text passing

T5: Refactor JS engine - remove old APIs, add forced breaks, page numbers, per-page alignment

T8: Add cover_text to API default_fields, apidoc (4 places), AGENTS.md

app/admin/controller/Post.php

@@ -358,7 +358,24 @@ class Post extends Common
         if (empty($model_post)) {
             $this->error('文章不存在');
         }
+
+        // 查询已有的排版输出，获取排版内容副本
+        $postOutput = \app\model\PostOutput::where('post_id', $id)
+            ->where('output_type', 'phone_image')
+            ->order('id', 'desc')
+            ->find();
+
+        // 排版内容副本：优先使用已保存的副本，否则使用原文
+        $layoutContentHtml = $model_post->content_html;
+        $layoutConfig = [];
+        if ($postOutput && !empty($postOutput->config['content_html'])) {
+            $layoutContentHtml = $postOutput->config['content_html'];
+            $layoutConfig = $postOutput->config;
+        }
+
         View::assign('post', $model_post);
+        View::assign('layoutContentHtml', $layoutContentHtml);
+        View::assign('layoutConfig', $layoutConfig);
         return View::fetch();
     }
 
@@ -395,6 +412,10 @@ class Post extends Common
         }
 
         $config = $data['config'] ?? [];
+        // 确保排版内容副本被保存到 config
+        if (isset($data['content_html']) && !isset($config['content_html'])) {
+            $config['content_html'] = $data['content_html'];
+        }
         $pages = $data['pages'] ?? [];
 
         $admin_id = session('admin_id') ?? 0;

app/api/controller/Articles.php

@@ -154,6 +154,7 @@ class Articles extends BaseController
             'jump_to_url_status' => 0,
             'poster' => '',
             'desc' => '',
+            'cover_text' => '',
             'author_name' => '',
             'hits' => 0,
             'is_top' => 0,