fix(2meet-data-optimizer): refuse aeav_only and cleanup on HivePress / WooCommerce sites

- Add TMDO_Promotion_Guard: HivePress models read every meta key with an
  empty-key get_*_meta() and WooCommerce does the same for products (and
  writes stock/sales with direct SQL), so on those sites native meta must
  stay authoritative. Promotion to aeav_only is refused in
  TMDO_Mode_Manager::set() (covers REST, CLI, phases, auto-promoter) for
  post/user/term/comment with HivePress and post/user with WooCommerce;
  TMDO_Post_Migration::cleanup() and the cleanup phase refuse too.
  Demotion stays open; filter tmdo_promotion_guard_allow overrides.
- Admin notice lists guarded entities already in aeav_only with the
  restore-native command (no forced demotion on read).
- Verify: PromotionGuardTest 8 OK; unit 668 OK, integration 480 OK,
  phpcs (phpcs.xml) 0, stan OK; dev36 live: 4 promotions + post-cleanup
  refused, wpdo_bridge_modes unchanged
- PR: PR-053

admin/class-tmdo-promotion-guard-notice.php

@@ -0,0 +1,63 @@
+<?php
+/**
+ * Admin notice when an entity is in aeav_only on a HivePress / WooCommerce site.
+ *
+ * Those plugins read native meta directly, so on an aeav_only entity they read
+ * stale (or, after cleanup, missing) values. The Promotion Guard refuses new
+ * promotions; sites promoted before it existed are only warned — demoting on
+ * read would leave them reading whatever native meta is left.
+ *
+ * @package WP_Data_Optimizer
+ */
+
+declare(strict_types=1);
+
+if ( ! defined( 'ABSPATH' ) ) {
+	exit;
+}
+
+/**
+ * Warns administrators about guarded entities that are already in aeav_only.
+ */
+final class TMDO_Promotion_Guard_Notice {
+
+	/**
+	 * Hook the notice.
+	 *
+	 * @return void
+	 */
+	public static function register(): void {
+		add_action( 'admin_notices', array( __CLASS__, 'render' ) );
+	}
+
+	/**
+	 * Print the notice for administrators when a guarded entity is in aeav_only.
+	 *
+	 * @return void
+	 */
+	public static function render(): void {
+		if ( ! current_user_can( 'manage_options' ) ) {
+			return;
+		}
+		$violations = TMDO_Promotion_Guard::violations();
+		if ( empty( $violations ) ) {
+			return;
+		}
+
+		$lines = array();
+		foreach ( $violations as $entity_type => $integrations ) {
+			$lines[] = sprintf( '%s（%s）：wp tmdo bridge-restore-native %s --demote', $entity_type, implode( ' / ', $integrations ), $entity_type );
+		}
+		printf(
+			'<div class="notice notice-error"><p><strong>%s</strong> %s</p></div>',
+			esc_html__( '2meet Data Optimizer：', '2meet-data-optimizer' ),
+			esc_html(
+				sprintf(
+					/* translators: %s: "entity (integrations): command" list */
+					__( '以下實體處於 aeav_only，但這些外掛會直接讀取原生 meta，可能讀到過期或遺失的資料。請先備份，再把扁平資料寫回原生並降級：%s', '2meet-data-optimizer' ),
+					implode( '；', $lines )
+				)
+			)
+		);
+	}
+}