fix(admin): close hero/banner config chain in page-display IA

Wire existing HeroManager/BannerManager into page-display routes and
component loaders, fix banner REST round-trip (show_meta + optional title),
and retarget operator deep-links to the real slide managers.

assets/admin/src/router/component-loaders/core.js

@@ -5,6 +5,8 @@ export const corePageLoaders = {
   FooterTabbarSettings: () => import('@/pages/content/FooterTabbarSettings.vue'),
   FooterSettings: () => import('@/pages/content/FooterSettings.vue'),
   HomepageSettings: () => import('@/pages/content/HomepageSettings.vue'),
+  HeroManager: () => import('@/pages/content/HeroManager.vue'),
+  BannerManager: () => import('@/pages/content/BannerManager.vue'),
   PostPageSettings: () => import('@/pages/post-list/PostPageSettings.vue'),
   CommentSettings: () => import('@/pages/post-list/CommentSettings.vue'),
   CommentPermissions: () => import('@/pages/permissions/CommentPermissions.vue'),