Add hook_ai_search_results_alter() to allow other modules to modify or re-rank AI search results

Currently, the AI Search processor in the ai_search module executes the search query and returns scored entity results directly.
There is no way for other modules to adjust or re-rank these results before they are returned.

This issue introduces a new hook:

hook_ai_search_results_alter(array &$results, $keywords)

Purpose

The new hook allows other modules to:

• Adjust or boost relevance scores for specific entities (e.g., promote certain content types).
• Filter or remove results.
• Reorder results based on custom business logic.

Example Implementation

function mymodule_ai_search_results_alter(array &$results, $keywords): void {
  // Example: Boost a specific node manually.
  if (isset($results['entity:node/8215:en'])) {
    $results['entity:node/8215:en'] += 0.2;
  }

  // Example: Slightly boost all "article" nodes.
  foreach ($results as $entity_id => $score) {
    if (preg_match('/^entity:node\/(\d+)/', $entity_id, $matches)) {
      $nid = (int) $matches[1];
      $node = \Drupal::entityTypeManager()->getStorage('node')->load($nid);
      if ($node && $node->bundle() === 'article') {
        $results[$entity_id] = $score + 0.05;
      }
    }
  }

  arsort($results);
}

Developer Notes

• The hook is invoked in the AiSearchProcessor::getAiSearchResults() method right before returning the $ai_entity_ids.
• It follows Drupal’s standard alter pattern.
• Example usage is documented in ai_search.api.php.

Benefits

• Extensibility: enables contrib and custom modules to influence AI ranking logic.
• Better integration with site-specific or domain-specific relevance tuning.
• Non-breaking change: existing functionality remains unaffected unless the hook is implemented.