refactor(zones): 回填 Zone_Router + Routing_Predicate（PR-C）

A v3.0.1/v3.4.0 的架構深化，B 完全缺席：

新增
- includes/zones/class-tmdo-zone-router.php：module_name / read / write /
  delete_field / delete_post 五個 static 分派點
- includes/class-tmdo-routing-predicate.php：entity_bridge_owns（含
  request-level cache，B 原本沒有）+ should_{write,read,query}_from_zone
  + flush_cache

改寫
- Sync_Bridge 改用兩者，移除 5 個 private wrapper（get_zone_module /
  read_from_zone / write_to_zone / delete_from_zone / is_owned_by_entity_bridge）
  與 44 行 inline cleanup_post → Zone_Router::delete_post 一行（400→269 行）
- Query_Router 抽出 extract_hot_clauses() public static，pre_get_posts 變薄殼
- 收斂 5 處重複的 'hot_'/'cold_' . sanitize_key()（rest-api ×3、
  hot/cold-migration ×2）
- back-compat 補 WPDO_Zone_Router / WPDO_Routing_Predicate alias

測試
- 移植 ZoneRouterTest（250 行）+ RoutingPredicateTest（85 行）
- SyncBridgeEntityGuardTest 的 setUp/tearDownAfterClass 補 flush_cache()，
  否則 entity_bridge_cache 會跨測試污染（A v3.4.6 踩過同一個坑）

unit 409 / integration 398 GREEN

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

tests/integration/SyncBridgeEntityGuardTest.php

@@ -114,6 +114,9 @@ class SyncBridgeEntityGuardTest extends TestCase {
 		$wpdb->query( 'DROP TABLE IF EXISTS `' . self::TABLE . '`' );
 		$wpdb->query( 'DROP TABLE IF EXISTS `wp_itest_wpdo_errors`' );
 
+		// Prevent this class's entity_bridge_cache entries leaking into later classes.
+		TMDO_Routing_Predicate::flush_cache();
+
 		// Reset Mode_Manager cache to prevent post=dual_write leaking into
 		// later tests that share the same PHP process (e.g. SyncBridgeIntegrationTest
 		// which uses 'hp_price' as a generic test field — that key is in the post
@@ -132,6 +135,10 @@ class SyncBridgeEntityGuardTest extends TestCase {
 		global $wpdb;
 		$wpdb->query( 'TRUNCATE TABLE `' . self::TABLE . '`' );
 
+		// Routing_Predicate memoises entity_bridge_owns() per request — clear it so
+		// each case sees the mode/registry state it just set up.
+		TMDO_Routing_Predicate::flush_cache();
+
 		$GLOBALS['_wp_options'] = array();
 		WPDO_Feature_Flags::set( self::MODULE, 'dual_write' );
 

tests/integration/bootstrap.php

@@ -522,6 +522,8 @@ require_once TMDO_PATH . 'includes/class-tmdo-conflict-monitor.php';
 require_once TMDO_PATH . 'includes/class-tmdo-compatibility.php';
 require_once TMDO_PATH . 'includes/interceptors/class-tmdo-interceptor-base.php';
 require_once TMDO_PATH . 'includes/interceptors/class-tmdo-sync-bridge.php';
+require_once TMDO_PATH . 'includes/zones/class-tmdo-zone-router.php';
+require_once TMDO_PATH . 'includes/class-tmdo-routing-predicate.php';
 require_once TMDO_PATH . 'includes/zones/class-tmdo-zone-hot.php';
 require_once TMDO_PATH . 'includes/zones/class-tmdo-zone-warm.php';
 require_once TMDO_PATH . 'includes/zones/class-tmdo-zone-cold.php';