Provide a mechanism to combine vector search with traditional search

Closes #3470414

modules/ai_search/src/EventSubscriber/SolrBoostByAiSearchEventSubscriber.php

+<?php
+
+namespace Drupal\ai_search\EventSubscriber;
+
+use Drupal\ai_search\Plugin\search_api\processor\SolrBoostByAiSearch;
+use Drupal\search_api_solr\Event\PostConvertedQueryEvent;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+
+/**
+ * Event subscriber to alter the Solarium query for AI boosting.
+ */
+class SolrBoostByAiSearchEventSubscriber implements EventSubscriberInterface {
+
+  /**
+   * Alters the Solarium query to boost AI results.
+   *
+   * @param \Drupal\ai_search\Event\PostConvertedQueryEvent $event
+   *   The event containing the Solarium query.
+   */
+  public function onPostConvertedQuery(PostConvertedQueryEvent $event) {
+    $solarium_query = $event->getSolariumQuery();
+    $query = $event->getSearchApiQuery();
+    SolrBoostByAiSearch::queryAlter($solarium_query, $query);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function getSubscribedEvents() {
+    return [
+      PostConvertedQueryEvent::class => 'onPostConvertedQuery',
+    ];
+  }
+
+}