feat: 收口 1:1 剩余欠账（论坛壳/圈子/501/私信默认/资源死码）

- 论坛 board/topic/plate/tag/plate-cat 接入 content-wrap/content-layout 主站流壳
- 公共主页 plate 圈子 tab 接关注/管理版块真实数据并计数
- forum-topic 渲染封面/付费扩展位 meta（§7.3）
- 后台删除消息/背景图/评论图 REST 从 501 补齐为真实实现
- 私信 private_s 缺省 true（完整 1:1，不再兼容默认关）
- 清理 aksrt_get_resource_meta 不可达旧实现；挂载 AKSRT_AI 配置门控实例
- 登录 modal 启用 colorful-header；订单页粉边 focus 软化；侧栏次级入口视觉弱化

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

templates/forum/forum-topic.php

@@ -60,8 +60,12 @@ if (empty($topic['can_view'])) :
     $credits_cost = (int) get_post_meta($topic_id, '_aksrt_credits_cost', true);
     $pay_price = get_post_meta($topic_id, '_aksrt_pay_price', true);
     ?>
-    <main id="main-content" class="site-main content-shell" tabindex="-1">
-        <div class="aksrt-forum-topic container">
+    <main id="main-content" class="site-main content-shell content-shell--stream content-shell--forum" tabindex="-1">
+    <div class="content-wrap container">
+        <div class="content-layout content-layout--no-sidebar">
+            <div class="content-layout__primary">
+
+        <div class="aksrt-forum-topic">
             <div class="aksrt-forum-topic__denied">
                 <i class="fas fa-eye-slash"></i>
                 <h1><?php esc_html_e('当前主题暂不可访问', 'aksrt'); ?></h1>
@@ -94,7 +98,11 @@ if (empty($topic['can_view'])) :
                 <?php endif; ?>
             </div>
         </div>
-    </main>
+    
+            </div>
+        </div>
+    </div>
+</main>
     <?php
     get_footer();
     return;
@@ -109,11 +117,43 @@ $is_locked = !empty($topic['locked']);
 $comments_enabled = !empty($permissions['can_reply']);
 ?>
 
-<main id="main-content" class="site-main content-shell" tabindex="-1">
+<main id="main-content" class="site-main content-shell content-shell--stream content-shell--forum" tabindex="-1">
+    <div class="content-wrap container">
+        <div class="content-layout content-layout--no-sidebar">
+            <div class="content-layout__primary">
+
 
     <?php if (function_exists('aksrt_breadcrumbs')) { aksrt_breadcrumbs(); } ?>
 
-    <div class="aksrt-forum-topic container">
+    <div class="aksrt-forum-topic">
+            <?php
+            // Cover + paid extensions for forum topics.
+            $cover_type = (string) get_post_meta(get_the_ID(), '_aksrt_cover_type', true);
+            $cover_image = (string) get_post_meta(get_the_ID(), '_aksrt_cover_image', true);
+            $cover_video = (string) get_post_meta(get_the_ID(), '_aksrt_featured_video', true);
+            $cover_ratio = (string) get_post_meta(get_the_ID(), '_aksrt_cover_ratio', true);
+            if ($cover_ratio === '') { $cover_ratio = '16:9'; }
+            if ($cover_type === 'image' && $cover_image !== '') : ?>
+                <div class="aksrt-forum-topic__cover aksrt-forum-topic__cover--image" style="--cover-ratio:<?php echo esc_attr(str_replace(':', '/', $cover_ratio)); ?>">
+                    <img src="<?php echo esc_url($cover_image); ?>" alt="" loading="lazy">
+                </div>
+            <?php elseif ($cover_type === 'video' && $cover_video !== '') : ?>
+                <div class="aksrt-forum-topic__cover aksrt-forum-topic__cover--video">
+                    <?php echo wp_oembed_get($cover_video) ?: esc_html($cover_video); // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped ?>
+                </div>
+            <?php elseif ($cover_type === 'slide') :
+                $slides = get_post_meta(get_the_ID(), '_aksrt_featured_slide', true);
+                if (is_array($slides) && $slides) : ?>
+                    <div class="aksrt-forum-topic__cover aksrt-forum-topic__cover--slide">
+                        <?php foreach ($slides as $slide) :
+                            $src = is_array($slide) ? (string) ($slide['url'] ?? $slide['src'] ?? '') : (string) $slide;
+                            if ($src === '') { continue; } ?>
+                            <img src="<?php echo esc_url($src); ?>" alt="" loading="lazy">
+                        <?php endforeach; ?>
+                    </div>
+                <?php endif; ?>
+            <?php endif; ?>
+
         <?php if ($show_breadcrumbs) : ?>
         <div class="aksrt-forum-topic__breadcrumb">
             <?php if ($bc_show_home) : ?>
@@ -667,6 +707,10 @@ $comments_enabled = !empty($permissions['can_reply']);
                 <a href="<?php echo esc_url(wp_login_url(get_permalink())); ?>"><?php esc_html_e('登录后参与回复', 'aksrt'); ?></a>
             </div>
         <?php endif; ?>
+    </div>
+
+            </div>
+        </div>
     </div>
 </main>