fix(user-center): restore page-owned dual-column sidebar layout

User center left nav (stats/services/commerce) stacked or hid after
content-layout lost its grid and the site float shell treated the
nested .sidebar as a widget column. Scope a CSS grid under
body.aksrt-user-center, neutralize site-layout float/hide, align the
drawer to ≤991.98, and drop the truncated #panel-credits selector.

assets/css/routes/profile/layout.css

@@ -470,18 +470,10 @@
 }
 
 
-/* 用户中心复用全站 content-layout，避免嵌套网格与双卡片负边距抵消。 */
+/* 用户中心 layout 间距；双栏 / sticky 见 user-center/shell.css（body.aksrt-user-center）。 */
 .aksrt-profile__layout {
   margin-top: 20px;
 }
-.aksrt-profile__aside.page-owned {
-  position: static;
-}
-@media (min-width: 992px) {
-  .aksrt-profile__aside.page-owned {
-    position: sticky;
-  }
-}
 .aksrt-user-center__notice {
   margin-bottom: 16px;
   padding: 12px 14px;