fix: 已解锁后 [paid] 标签裸露——替换为付费内容块

post.rendered 过滤原只在无权限时替换 [paid]；有权限时原始标签直接显示在页面。现在：
- 有权限：替换为 <div class="paid-content"> 付费内容块（带「付费内容」小标签），三套主题补齐样式
- 先去掉 Markdown 转换产生的 <p>[paid]</p> 包裹，避免替换后残留未闭合标签
- 测试：游客与会员均断言不出现裸 [paid]

plugins/neatstudio.membership/src/ServiceProvider.php

@@ -53,15 +53,24 @@ class ServiceProvider extends PluginServiceProvider
             }
         }, 10);
 
-        // 付费文章：[paid]...[/paid] 对无权限访客隐藏为 teaser；整篇锁定渲染 paywall
+        // 付费文章：[paid]...[/paid] —— 无权限访客替换为 teaser；有权限替换为付费内容块（避免原始标签裸露在页面）
         $manager->addFilter('post.rendered', function (string $html, \App\Models\Post $post) {
             $service = app(Services\MembershipService::class);
             $user = auth()->user();
 
-            if (preg_match('/\[paid\](.*?)\[\/paid\]/s', $html) && ! $service->canReadPaidContent($user, $post)) {
+            if (preg_match('/\[paid\](.*?)\[\/paid\]/s', $html)) {
+                // Markdown 转换会给短代码包上 <p>，先去掉，避免替换后残留未闭合标签
+                $html = preg_replace('/<p>\s*\[(\/?paid)\]\s*<\/p>/i', '[$1]', $html);
+
                 $html = preg_replace_callback(
                     '/\[paid\](.*?)\[\/paid\]/s',
-                    fn () => view('membership.paid-teaser', ['post' => $post])->render(),
+                    function (array $m) use ($service, $user, $post) {
+                        if ($service->canReadPaidContent($user, $post)) {
+                            return '<div class="paid-content"><div class="paid-content-label">付费内容</div>'.trim($m[1]).'</div>';
+                        }
+
+                        return view('membership.paid-teaser', ['post' => $post])->render();
+                    },
                     $html
                 );
             }