style(ui06): full-width pages — hand padding back to Art/ElMain container (user adjustment)

用户将全局 .ui06-page 的 30px 边距/1660 限宽注释（内容铺满，边距交还
ElMain 默认 20px）；manage 页 scoped 同名类同步、清理媒体查询死引用。

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

apps/admin/src/assets/styles/custom/ui06.scss

@@ -114,11 +114,11 @@ body {
 
 /* ══════════ 治理页通用（示例 .workspace / .page-heading / .stats / .stat / .info-strip） ══════════ */
 
-.ui06-page {
+// .ui06-page {
-  max-width: 1660px;
+//   max-width: 1660px;
-  padding: 28px 30px 44px;
+//   padding: 28px 30px 44px;
-  margin: auto;
+//   margin: auto;
-}
+// }
 
 .ui06-page-heading {
   display: flex;
@@ -205,10 +205,6 @@ body {
     gap: 10px;
   }
 
-  .ui06-page {
-    padding: 20px 14px 40px;
-  }
-
   .ui06-page-heading {
     flex-direction: column;
     align-items: flex-start;

apps/admin/src/views/albums/manage/index.vue

@@ -267,11 +267,11 @@
   @reference '@styles/core/tailwind.css';
 
   /* 对齐示例 .workspace / .page-heading / .toolbar / .summary-line / .album-grid / .load-more */
-  .ui06-page {
+  // .ui06-page {
-    max-width: 1660px;
+  // max-width: 1660px;
-    padding: 28px 30px 44px;
+  // padding: 28px 30px 44px;
-    margin: auto;
+  // margin: auto;
-  }
+  // }
 
   .page-heading {
     display: flex;