fix: Page list not refreshing and dialog styling

- Fix api response handling in pages query (api returns JSON directly)
- Fix page-structure query response handling
- Add theme class copying to dialog portal for proper CSS variable inheritance
- Portal container now syncs with document theme (light/dark)

admin-spa/src/routes/Appearance/Pages/index.tsx

@@ -51,8 +51,9 @@ export default function AppearancePages() {
     const { data: pages = [], isLoading: pagesLoading } = useQuery<PageItem[]>({
         queryKey: ['pages'],
         queryFn: async () => {
+            // api.get returns JSON directly (not wrapped in { data: ... })
             const response = await api.get('/pages');
-            return response.data;
+            return response; // Return response directly
         },
     });
 
@@ -64,8 +65,9 @@ export default function AppearancePages() {
             const endpoint = selectedPage.type === 'page'
                 ? `/pages/${selectedPage.slug}`
                 : `/templates/${selectedPage.cpt}`;
+            // api.get returns JSON directly
             const response = await api.get(endpoint);
-            return response.data;
+            return response; // Return response directly
         },
         enabled: !!selectedPage,
     });