refactor: flatten src/AKSRT → src (drop theme-identifier dir)

Move all domain folders from src/AKSRT/{Domain} to src/{Domain}; remap
Composer PSR-4 "AKSRT\\": "src/"; update audit script + README + ADR
paths; remove dead tools/build-psr4-map.php (scanned deleted inc/classes).

src/Core/DBMigratorPart3.php

@@ -0,0 +1,46 @@
+<?php
+/**
+ * @package AKSRT
+ */
+
+namespace AKSRT\Core;
+
+defined('ABSPATH') || exit;
+
+trait DBMigratorPart3 {
+
+
+    /**
+     * 表名访问器（其它模块通过此函数取，避免散落硬编码）。
+     */
+    public static function table(string $name): string {
+        global $wpdb;
+        $allowed = [
+            'credit_log'     => 'aksrt_credit_log',
+            'balance_log'    => 'aksrt_balance_log',
+            'signin_log'     => 'aksrt_signin_log',
+            'invite'         => 'aksrt_invite',
+            'dl_token'       => 'aksrt_dl_token',
+            'notification'   => 'aksrt_notification',
+            'conversation'   => 'aksrt_conversation',
+            'conv_message'   => 'aksrt_conversation_message',
+            'order'          => 'aksrt_order',
+            'order_item'     => 'aksrt_order_item',
+            'revenue'        => 'aksrt_revenue',
+            'withdrawal'     => 'aksrt_withdrawal',
+            'report'         => 'aksrt_report',
+            'follow'         => 'aksrt_follow',
+            'coupon'         => 'aksrt_coupon',
+            'charge_card'    => 'aksrt_charge_card',
+            'rebate_log'     => 'aksrt_rebate_log',
+            'coupon_usage'         => 'aksrt_coupon_usage',
+            'user_restriction'     => 'aksrt_user_restriction',
+            'identity_application' => 'aksrt_identity_application',
+            'identity_event'       => 'aksrt_identity_event',
+        ];
+        if (!isset($allowed[$name])) {
+            return '';
+        }
+        return $wpdb->prefix . $allowed[$name];
+    }
+}