feat(admin): host the ban/report settings page in the SPA schema

The users-interaction sidebar entry 禁封/举报 was a redirect stub; it is
now a schema-driven settings page replicating the reference theme
field-for-field:

- user_ban_s / user_report_s switches, ban_preset_reason and
  ban_appeal_keys as repeatable group rows ({t}), ban_appeal_desc and
  user_report_desc HTML textareas with the reference default copy, and
  user_report_img_s — keys, labels, help texts, defaults and ordering
  all mirrored in SchemaUsers.php and the SPA report.js schema
- UserRuntime::ban_settings()/report_settings() and
  BanAppeal::settings() read the new group-array values with fallback
  to the previous line/comma formats
- delete the self-built SPA queue pages (UsersBan, UsersReport,
  ReportDetailDrawer, UsersMessages) that the reference theme does not
  have; legacy /users/report bookmarks still redirect to the native page
- contract tests: lock the schema keys/labels, the schemaPage mount and
  the deleted-file state; drop reads of removed components

tests/widget-system/message-center-contract.test.cjs

@@ -103,8 +103,7 @@ test('asset notifications are absent and interaction notification hooks are pres
   const notifications = read('inc/modules/user-notifications.php');
   const settings = read('src/Settings/Integration.php');
   const adminSettings = read('assets/admin/src/pages/content/NotificationCenterSettings.vue');
-  const messageAdmin = read('assets/admin/src/pages/users/UsersMessages.vue');
-  const combined = [notifications, settings, adminSettings, messageAdmin].join('\n');
+  const combined = [notifications, settings, adminSettings].join('\n');
 
   for (const retired of [
     'asset_points_increase',