feat: Adds hybrid search options contract for multisearch

src/Contracts/HybridSearchOptions.php

@@ -0,0 +1,33 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MeiliSearch\Contracts;
+
+class HybridSearchOptions
+{
+    private ?float $semanticRatio = null;
+    private ?string $embedder = null;
+
+    public function setSemanticRatio(float $ratio): HybridSearchOptions
+    {
+        $this->semanticRatio = $ratio;
+
+        return $this;
+    }
+
+    public function setEmbedder(string $embedder): HybridSearchOptions
+    {
+        $this->embedder = $embedder;
+
+        return $this;
+    }
+
+    public function toArray(): array
+    {
+        return array_filter([
+            'semanticRatio' => $this->semanticRatio,
+            'embedder' => $this->embedder,
+        ], static function ($item) { return null !== $item; });
+    }
+}

src/Contracts/SearchQuery.php

@@ -27,6 +27,7 @@
     private ?int $hitsPerPage;
     private ?int $page;
     private ?array $vector;
+    private ?HybridSearchOptions $hybrid;
     private ?array $attributesToSearchOn = null;
     private ?bool $showRankingScore = null;
     private ?bool $showRankingScoreDetails = null;
@@ -237,6 +238,22 @@
         return $this;
     }
 
+    /**
+     * This is an EXPERIMENTAL feature, which may break without a major version.
+     *
+     * Set hybrid search options
+     * [
+     * 'semanticRatio'=> 0.8,
+     * 'embedder' => 'manual',
+     * ];
+     */
+    public function setHybrid(HybridSearchOptions $hybridOptions): SearchQuery
+    {
+        $this->hybrid = $hybridOptions;
+
+        return $this;
+    }
+
     /**
      * @param list<non-empty-string> $attributesToSearchOn
      */
@@ -270,6 +287,7 @@
             'hitsPerPage' => $this->hitsPerPage ?? null,
             'page' => $this->page ?? null,
             'vector' => $this->vector ?? null,
+            'hybrid' => null !== $this->hybrid ? $this->hybrid->toArray() : null,
             'attributesToSearchOn' => $this->attributesToSearchOn,
             'showRankingScore' => $this->showRankingScore,
             'showRankingScoreDetails' => $this->showRankingScoreDetails,