perf(2meet-data-optimizer-hivepress-addon): index the numeric listing columns HivePress filters and sorts on

- hp_listing_core declares indexes on hp_hourly_rate and hp_rating_count; core
  adds them in place (WP-CLI / WP-Cron), the pinned schema hash is unchanged
- Verify: unit 145, integration 52, phpcs; dev36 902k listings (SHOW INDEX, EXPLAIN)
- PR: PR-090

includes/class-tmdo-hivepress-entity-groups.php

@@ -257,7 +257,16 @@ final class TMDO_HivePress_Entity_Groups {
 					'label' => 'Hourly rate',
 				),
 			),
-			array( 'post_types' => array( 'hp_listing' ) )
+			array(
+				'post_types' => array( 'hp_listing' ),
+				// Filtered and sorted on by HivePress search. Declared as indexes
+				// (added in place) rather than `searchable`, which would change
+				// the schema hash and rebuild a table that may hold aeav_only data.
+				'indexes'    => array(
+					'hourly_rate'  => array( 'hp_hourly_rate' ),
+					'rating_count' => array( 'hp_rating_count' ),
+				),
+			)
 		);
 	}
 	/**