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/PostQueryRouterFoundRowsTest.php

@@ -90,6 +90,17 @@ class PostQueryRouterFoundRowsTest extends TestCase {
 		return array( $router, $query, $request );
 	}
 
+	public function test_a_group_waiting_for_its_table_upgrade_is_not_routed(): void {
+		$mode = new ReflectionProperty( WPDO_Mode_Manager::class, 'cache' );
+		$mode->setAccessible( true );
+		$mode->setValue( null, array( 'post' => 'shadow_read', 'user' => 'disabled', 'term' => 'disabled', 'comment' => 'disabled' ) );
+		update_option( TMDO_Schema_Manager::DEFERRED_OPTION, array( 'post/fr_core' => time() ) );
+
+		list( , $query ) = $this->routed();
+
+		$this->assertEmpty( $query->get( 'wpdo_post_clauses' ), 'kept native' );
+	}
+
 	public function test_routed_request_drops_sql_calc_found_rows(): void {
 		list( $router, $query, $request ) = $this->routed();