refac: API 캐시 컨트롤에서 max-age, public 지정 가능하도록

src/sammo/APICacheResult.php

@@ -5,6 +5,8 @@ class APICacheResult{
     function __construct(
         public ?\DateTimeInterface $lastModified = null,
         public ?string $etag = null,
+        public int $validSeconds = 60,
+        public bool $isPublic = false,
     )
     {
     }