feat(users): add native VIP management

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

src/Core/DBMigratorVip.php

@@ -0,0 +1,42 @@
+<?php
+/**
+ * VIP membership audit table.
+ *
+ * @package AKSRT
+ */
+
+namespace AKSRT\Core;
+
+defined('ABSPATH') || exit;
+
+trait DBMigratorVip {
+
+    private static function migrate_vip_tables(string $prefix, string $charset_collate): void {
+        $event = "CREATE TABLE {$prefix}aksrt_vip_membership_event (
+            id BIGINT UNSIGNED NOT NULL AUTO_INCREMENT,
+            event_uuid CHAR(36) NOT NULL,
+            batch_uuid CHAR(36) NOT NULL DEFAULT '',
+            user_id BIGINT UNSIGNED NOT NULL,
+            actor_user_id BIGINT UNSIGNED DEFAULT NULL,
+            operation VARCHAR(16) NOT NULL,
+            source VARCHAR(20) NOT NULL DEFAULT 'admin',
+            reason VARCHAR(255) NOT NULL DEFAULT '',
+            request_json LONGTEXT DEFAULT NULL,
+            before_json LONGTEXT DEFAULT NULL,
+            after_json LONGTEXT DEFAULT NULL,
+            status VARCHAR(16) NOT NULL DEFAULT 'pending',
+            error_code VARCHAR(64) NOT NULL DEFAULT '',
+            error_message VARCHAR(255) NOT NULL DEFAULT '',
+            created_at DATETIME NOT NULL,
+            completed_at DATETIME DEFAULT NULL,
+            PRIMARY KEY  (id),
+            UNIQUE KEY uniq_event_uuid (event_uuid),
+            KEY idx_user_created (user_id, created_at),
+            KEY idx_actor_created (actor_user_id, created_at),
+            KEY idx_batch (batch_uuid),
+            KEY idx_status_created (status, created_at),
+            KEY idx_operation_created (operation, created_at)
+        ) {$charset_collate};";
+        dbDelta($event);
+    }
+}