feat(frontend): align single related/prevnext/maxheight with Zibll

Honor prevnext/authordesc/yiyan settings, multi-tax related queries with
orderby (incl. views), per-post maxheight override, and only expand content
when maxheight is enabled.

inc/classes/admin/schema/class-aksrt-admin-schema-post-list.php

@@ -103,6 +103,8 @@ class AKSRT_Admin_Schema_Post_List {
                                 ['label' => '随机', 'value' => 'rand'],
                                 ['label' => '相关度', 'value' => 'relevance'],
                                 ['label' => '时间', 'value' => 'date'],
+                                ['label' => '浏览量', 'value' => 'views'],
+                                ['label' => '更新时间', 'value' => 'modified'],
                             ]],
                             ['key' => 'post_related_title', 'label' => '推荐标题', 'type' => 'input', 'default' => '相关推荐'],
                         ]],