fix(2meet-data-optimizer): upgrade existing flat tables from WP-CLI or WP-Cron only

- a changed group definition no longer runs dbDelta on an existing table
  inside a web request (seconds to minutes on a large table, and every
  concurrent request tried it): the group is recorded in tmdo_schema_deferred
  and tmdo_ensure_group_indexes is scheduled, whose request upgrades it
- meanwhile the group stays native: Hook Bus field lookups return no field and
  the router treats it as drifting; afterwards a drift fix
  (tmdo_drift_resync) rebuilds the writes that skipped the flat table
- new tables are still created at once; aeav_only upgrades at once (the flat
  table is the only copy); doctor lists deferred groups
- Verify: SchemaUpgradeDeferralTest, Hook Bus and router tests, integration
  582, unit 701, phpcs, stan; dev36 live cycle in the 2.3 acceptance
- PR: PR-107

tests/integration/HookBusIntegrationTest.php

@@ -227,6 +227,29 @@ class HookBusIntegrationTest extends TestCase {
 		);
 	}
 
+	/**
+	 * A group whose table upgrade waits for WP-CLI / WP-Cron (2.3 PR-107)
+	 * stays native: its table may lack the new columns.
+	 */
+	public function test_a_group_waiting_for_its_table_upgrade_stays_native(): void {
+		global $wpdb;
+		self::set_user_mode( WPDO_Mode_Manager::MODE_DUAL_WRITE );
+		update_option( TMDO_Schema_Manager::DEFERRED_OPTION, array( 'user/core_profile' => time() ) );
+		try {
+			$this->with_usermeta(
+				function () use ( $wpdb ) {
+					$wpdb->insert( $wpdb->usermeta, array( 'user_id' => 4, 'meta_key' => 'first_name', 'meta_value' => 'Dora' ) );
+
+					WPDO_Hook_Bus::sync_from_native( 'user', 4, 'first_name', 'Dora', 'update' );
+
+					$this->assertNull( $this->read_flat_first_name( 4 ) );
+				}
+			);
+		} finally {
+			delete_option( TMDO_Schema_Manager::DEFERRED_OPTION );
+		}
+	}
+
 	/**
 	 * delete_all passes object ID 0: the delete_ action records the touched
 	 * users from the meta IDs, the deleted_ action re-syncs each to NULL.