refactor(2meet-data-optimizer-hivepress-addon): stop registering Hot zone fields

- ADR-003 step 4 (AddOn side): core, requests, bookings, memberships and
  marketplace adapters no longer register zone=hot fields or contribute
  hot_* FSM modules; their keys live in TMDO_HivePress_Entity_Groups.
  Cold/warm registrations are unchanged.
- Hot-table doctor probes go with them (trait defaults apply). The
  hot-clause query rewrite and cron optimizer are now inert and are left
  for the ADR step-5 removal together with core's hot path.
- New NoHotZoneRegistrationTest pins the invariant across all 13 adapters;
  per-adapter hot assertions removed.
- Verify: HP unit 142 / integration 49 green, phpcs clean (WordPress)
- PR: PR-037

tests/unit/NoHotZoneRegistrationTest.php

@@ -0,0 +1,51 @@
+<?php
+declare(strict_types=1);
+
+use PHPUnit\Framework\TestCase;
+
+/**
+ * ADR-003: post fields converge on entity groups; the Hot zone is frozen.
+ *
+ * No HivePress adapter registers zone=hot fields or contributes hot_* FSM
+ * modules. The fields they used to cover live in TMDO_HivePress_Entity_Groups.
+ */
+class NoHotZoneRegistrationTest extends TestCase {
+
+	private const ADAPTERS = array(
+		'TMDO_HivePress_Core_Adapter',
+		'TMDO_HivePress_Requests_Adapter',
+		'TMDO_HivePress_Bookings_Adapter',
+		'TMDO_HivePress_Memberships_Adapter',
+		'TMDO_HivePress_Marketplace_Adapter',
+		'TMDO_HivePress_Favorites_Adapter',
+		'TMDO_HivePress_Reviews_Adapter',
+		'TMDO_HivePress_Social_Links_Adapter',
+		'TMDO_HivePress_Blocks_Adapter',
+		'TMDO_HivePress_Seo_Adapter',
+		'TMDO_HivePress_Messages_Adapter',
+		'TMDO_HivePress_Statistics_Adapter',
+		'TMDO_HivePress_Tags_Adapter',
+	);
+
+	protected function setUp(): void {
+		$prop = ( new ReflectionClass( TMDO_Schema_Registry::class ) )->getProperty( 'instance' );
+		$prop->setAccessible( true );
+		$prop->setValue( null, null );
+	}
+
+	public function test_no_adapter_registers_hot_fields(): void {
+		$registry = TMDO_Schema_Registry::instance();
+		foreach ( self::ADAPTERS as $class ) {
+			( new $class() )->on_register_fields( $registry );
+		}
+
+		$this->assertSame( array(), $registry->get_zone_fields( 'hot' ) );
+		$this->assertSame( 'cold', $registry->get_field_zone( 'hp_listing', 'hp_images' ), 'cold fields stay' );
+	}
+
+	public function test_no_adapter_contributes_hot_modules(): void {
+		foreach ( self::ADAPTERS as $class ) {
+			$this->assertSame( array(), ( new $class() )->migrations(), $class );
+		}
+	}
+}