refactor(classes): organize inc/classes into domain folders

Move ~94 root class shells and root *-traits into domain directories
(core, auth, user, credits, content, payment/gateways, forum, shop,
sms, ai, messages, extensions, widgets, settings, admin). Update
bootstrap require paths, co-locate traits with owners, fix forum/user
relative requires, drop duplicate shop controller requires, and wire
home-modules load. Path-only; class names and init order unchanged.

inc/classes/sms/class-aksrt-sms-provider-factory.php

@@ -0,0 +1,69 @@
+<?php
+/**
+ * AKSRT SMS Provider Factory
+ *
+ * 根据 provider key 返回对应的 adapter 实例。
+ * 内部维护静态注册表，避免重复实例化。
+ *
+ * @package AKSRT
+ */
+
+defined('ABSPATH') || exit;
+
+class AKSRT_SMS_Provider_Factory {
+
+    private static $providers = [];
+
+    /**
+     * 获取供应商 adapter 实例
+     */
+    public static function get(string $key): ?AKSRT_SMS_Provider {
+        $key = sanitize_key($key);
+        if ($key === '') return null;
+
+        if (isset(self::$providers[$key])) {
+            return self::$providers[$key];
+        }
+
+        $instance = self::create($key);
+        if ($instance !== null) {
+            self::$providers[$key] = $instance;
+        }
+        return $instance;
+    }
+
+    /**
+     * 获取所有已注册供应商
+     *
+     * @return AKSRT_SMS_Provider[]
+     */
+    public static function all(): array {
+        $keys = ['aliyun', 'tencent', 'huawei', 'custom'];
+        $result = [];
+        foreach ($keys as $key) {
+            $provider = self::get($key);
+            if ($provider !== null) {
+                $result[$key] = $provider;
+            }
+        }
+        return $result;
+    }
+
+    /**
+     * 创建 adapter 实例
+     */
+    private static function create(string $key): ?AKSRT_SMS_Provider {
+        switch ($key) {
+            case 'aliyun':
+                return class_exists('AKSRT_SMS_Provider_Aliyun') ? new AKSRT_SMS_Provider_Aliyun() : null;
+            case 'tencent':
+                return class_exists('AKSRT_SMS_Provider_Tencent') ? new AKSRT_SMS_Provider_Tencent() : null;
+            case 'huawei':
+                return class_exists('AKSRT_SMS_Provider_Huawei') ? new AKSRT_SMS_Provider_Huawei() : null;
+            case 'custom':
+                return class_exists('AKSRT_SMS_Provider_Custom') ? new AKSRT_SMS_Provider_Custom() : null;
+            default:
+                return null;
+        }
+    }
+}