Various code cleanup.

app/Support/System/OAuthKeys.php

@@ -32,6 +32,7 @@ use Laravel\Passport\Console\KeysCommand;
 use Psr\Container\ContainerExceptionInterface;
 use Psr\Container\NotFoundExceptionInterface;
 
+use Safe\Exceptions\FilesystemException;
 use function Safe\file_get_contents;
 use function Safe\file_put_contents;
 
@@ -79,7 +80,11 @@ class OAuthKeys
     }
 
     /**
+     * @return bool
+     * @throws ContainerExceptionInterface
      * @throws FireflyException
+     * @throws NotFoundExceptionInterface
+     * @throws FilesystemException
      */
     public static function restoreKeysFromDB(): bool
     {