feat(modal): add rollout telemetry foundation

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

src/Settings/DomainGroups.php

@@ -178,4 +178,13 @@ trait DomainGroups {
     public static function get_system_tools_settings(): array {
         return Capabilities::get_system_tools_settings();
     }
+
+    /**
+     * 获取前台弹窗按领域灰度开关。
+     *
+     * @return array{identity:bool,badges:bool,orders:bool,vip:bool}
+     */
+    public static function get_frontend_modal_rollout_settings(): array {
+        return ModalRuntime::get_frontend_modal_rollout_settings();
+    }
 }