fix: prevent ES CPU saturation from has_child scoring all posts

Without minimum_should_match=1 on the inner post bool query, Elasticsearch
defaults MSM to 0 whenever a filter clause is present. This caused has_child
to score every non-hidden post on every search request, saturating CPU on
shared ES nodes with large corpora (3.7M+ posts).

- Add BoolQuery subclass with create() override and minimumShouldMatch()
  (spatie/elasticsearch-query-builder 1.x uses `new self()` in create(),
  so subclassing requires overriding it)
- Set minimumShouldMatch(1) on the inner post query after adding the
  is_hidden filter, so only genuinely matching posts are scored
- Remove the operator('or') clause from buildShouldClauses() — with
  Turkish min_ngram=2, 'or' generates 2-gram tokens that match nearly
  every post, causing near-total index scans
- Add ES client timeouts (connect: 2s, query: 10s) to prevent Apache
  mod_php worker saturation when ES is slow or unreachable

src/Api/Controllers/SearchController.php

@@ -37,7 +37,7 @@ use Illuminate\Support\Str;
 use Psr\Http\Message\ServerRequestInterface;
 use Psr\Log\LoggerInterface;
 use Spatie\ElasticsearchQueryBuilder\Builder;
-use Spatie\ElasticsearchQueryBuilder\Queries\BoolQuery;
+use Blomstra\Search\Elasticsearch\BoolQuery;
 use Spatie\ElasticsearchQueryBuilder\Queries\TermQuery;
 use Spatie\ElasticsearchQueryBuilder\Sorts\Sort;
 use Tobscure\JsonApi\Document;
@@ -217,6 +217,10 @@ class SearchController extends ListDiscussionsController
                 $postQuery->add(TermQuery::create('is_hidden', 'false'), 'filter');
             }
 
+            // Without minimum_should_match, ES default MSM is 0 when a filter clause is present,
+            // causing has_child to score every non-hidden post instead of only matching ones.
+            $postQuery->minimumShouldMatch(1);
+
             $textQuery->add(
                 HasChildQuery::create('post', $postQuery)->withInnerHits(),
                 'should'
@@ -235,7 +239,6 @@ class SearchController extends ListDiscussionsController
         }
         if ($this->matchWords) {
             $should->add((new MatchQuery('content', $search))->operator('and')->boost(1.8 * $boost), 'should');
-            $should->add((new MatchQuery('content', $search))->operator('or')->boost(0.8 * $boost), 'should');
         }
 
         return $should;

src/Elasticsearch/BoolQuery.php

@@ -0,0 +1,41 @@
+<?php
+
+/*
+ * This file is part of blomstra/search.
+ *
+ * Copyright (c) 2022 Blomstra Ltd.
+ *
+ * For the full copyright and license information, please view the LICENSE.md
+ * file that was distributed with this source code.
+ *
+ */
+
+namespace Blomstra\Search\Elasticsearch;
+
+class BoolQuery extends \Spatie\ElasticsearchQueryBuilder\Queries\BoolQuery
+{
+    protected ?int $minimumShouldMatch = null;
+
+    public static function create(): static
+    {
+        return new self();
+    }
+
+    public function minimumShouldMatch(int $minimum): static
+    {
+        $this->minimumShouldMatch = $minimum;
+
+        return $this;
+    }
+
+    public function toArray(): array
+    {
+        $array = parent::toArray();
+
+        if ($this->minimumShouldMatch !== null) {
+            $array['bool']['minimum_should_match'] = $this->minimumShouldMatch;
+        }
+
+        return $array;
+    }
+}

src/Provider.php

@@ -47,7 +47,13 @@ class Provider extends AbstractServiceProvider
 
         $this->container->singleton(Elastic::class, function (Container $container) use ($settings, $config) {
             $builder = ClientBuilder::create()
-                ->setHosts([$settings->get('blomstra-search.elastic-endpoint')]);
+                ->setHosts([$settings->get('blomstra-search.elastic-endpoint')])
+                ->setConnectionParams([
+                    'client' => [
+                        'connect_timeout' => 2,  // fail fast if ES is unreachable
+                        'timeout'         => 10, // allow time for complex queries
+                    ],
+                ]);
 
             if ($config->inDebugMode()) {
                 $builder->setLogger($container->make(LoggerInterface::class));