Add real replacement pages for Pages, Media Library, and Users (v2.6.0)

Completes the "skinned vs. replaced" conversion started with Posts —
every native list-table screen the user asked about now has a genuine
custom Vue page behind it instead of dark-themed CSS over the native
markup. All three follow the same pattern as Posts: own REST controller
in admin/src/Rest/, own Vue page matching the Comments layout, native
screen redirected away (direct visits too, not just the sidebar link),
gated by its own Settings toggle defaulting to on.

- Pages (PagesData.php + Pages.vue): same as Posts, parent page shown
  instead of categories. edit.php?post_type=page redirects; other post
  types untouched.
- Media Library (MediaData.php + Media.vue): thumbnail grid with type
  filters (Images/Audio/Video/Documents/Unattached). Replaces the
  browse/library experience only — media-new.php (the actual upload
  screen) is untouched, same reasoning as leaving the block editor
  alone for Posts/Pages.
- Users (UsersData.php + Users.vue): filterable by role. Deleting a
  user always reassigns their content to whoever performs the deletion
  rather than exposing WP core's reassign-or-delete-everything choice
  as a one-click action — deliberately simplified to avoid a surprising,
  highly destructive default. user-new.php untouched.

Verified live: Media's grid renders real thumbnails/dimensions/file
sizes with working filters and search; Users shows real accounts with
role filters and correctly hides delete for the current user; both
redirect correctly from their native URLs.

Co-Authored-By: Claude Sonnet 5 <[email protected]>

app/src/pages/settings/settingsConfig.js

@@ -167,6 +167,21 @@ export const settingsCategories = [
       },
     ],
   },
+  {
+    id: 'pages',
+    title: 'Pages',
+    subtitle: 'Page management and display preferences',
+    icon: 'dashicons-admin-page',
+    fields: [
+      {
+        key: 'modern_pages',
+        type: 'toggle',
+        label: 'Modern pages table',
+        description: 'Use the Aurora pages management interface.',
+        default: true,
+      },
+    ],
+  },
   {
     id: 'plugins',
     title: 'Plugins',
@@ -224,6 +239,13 @@ export const settingsCategories = [
     subtitle: 'Media library and upload management settings',
     icon: 'dashicons-admin-media',
     fields: [
+      {
+        key: 'modern_media',
+        type: 'toggle',
+        label: 'Modern media library',
+        description: 'Use the Aurora media library interface.',
+        default: true,
+      },
       {
         key: 'enable_svg',
         type: 'toggle',
@@ -232,6 +254,21 @@ export const settingsCategories = [
       },
     ],
   },
+  {
+    id: 'users',
+    title: 'Users',
+    subtitle: 'User management and administration settings',
+    icon: 'dashicons-admin-users',
+    fields: [
+      {
+        key: 'modern_users',
+        type: 'toggle',
+        label: 'Modern users page',
+        description: 'Use the Aurora users management interface.',
+        default: true,
+      },
+    ],
+  },
   {
     id: 'comments',
     title: 'Comments',