feat(back-compat): 加入 WPDO_* class alias（E3）

核心的 class-tmdo-back-compat.php 在 plugins_loaded:4 執行，AddOn 於 :6
才載入，所以核心的 alias 表涵蓋不到 AddOn 類別 —— 姊妹外掛或第三方若
以 WPDO_* 名稱引用本 AddOn 的類別會直接 fatal。

新增 includes/back-compat-aliases.php，於 plugins_loaded:7 為本 AddOn
自有類別建立 WPDO_ alias；主檔加入 require。

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TbG1keQQ7XBa7qMQY16KCY

includes/back-compat-aliases.php

@@ -0,0 +1,31 @@
+<?php
+/**
+ * Backward-compat class aliases for the mobile-bridge AddOn.
+ *
+ * Sister plugins and third-party code may still reference the WPDO_* class
+ * names from wp-data-optimizer. The core plugin aliases its own classes in
+ * class-tmdo-back-compat.php, but it runs before AddOns load (plugins_loaded:4
+ * vs :6), so each AddOn must alias its own classes here.
+ *
+ * @package TMDO
+ */
+
+if ( ! defined( 'ABSPATH' ) ) {
+	exit;
+}
+
+add_action(
+	'plugins_loaded',
+	static function () {
+		$aliases = array(
+			'TMDO_Mobile_Bridge' => 'WPDO_Mobile_Bridge',
+			'TMDO_Mobile_Bridge_Bootstrap' => 'WPDO_Mobile_Bridge_Bootstrap',
+		);
+		foreach ( $aliases as $tmdo_class => $wpdo_alias ) {
+			if ( class_exists( $tmdo_class, false ) && ! class_exists( $wpdo_alias, false ) ) {
+				class_alias( $tmdo_class, $wpdo_alias );
+			}
+		}
+	},
+	7
+);