Convert other errors

src/Client.php

@@ -53,18 +53,12 @@ public function __construct(
         if ($secretKey === null) {
             $env = getenv('SNAPAUTH_SECRET_KEY');
             if ($env === false) {
-                throw new ApiError(
-                    'Secret key missing. It can be explictly provided, or it ' .
-                    'can be auto-detected from the SNAPAUTH_SECRET_KEY ' .
-                    'environment variable.',
-                );
+                throw new Exception\MissingSecretKey();
             }
             $secretKey = $env;
         }
         if (!str_starts_with($secretKey, 'secret_')) {
-            throw new ApiError(
-                'Invalid secret key. Please verify you copied the full value from the SnapAuth dashboard.',
-            );
+            throw new Exception\InvalidSecretKey();
         }
 
         $this->secretKey = $secretKey;

src/Exception/InvalidSecretKey.php

@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+namespace SnapAuth\Exception;
+
+use InvalidArgumentException;
+use SnapAuth\ApiError;
+
+class InvalidSecretKey extends InvalidArgumentException implements ApiError
+{
+    public function __construct()
+    {
+        parent::__construct(
+            message: 'Invalid secret key. Please verify you copied the full value from the SnapAuth dashboard.',
+        );
+    }
+}

src/Exception/MissingSecretKey.php

@@ -0,0 +1,19 @@
+<?php
+
+declare(strict_types=1);
+
+namespace SnapAuth\Exception;
+
+use InvalidArgumentException;
+use SnapAuth\ApiError;
+
+class MissingSecretKey extends InvalidArgumentException implements ApiError
+{
+    public function __construct()
+    {
+        parent::__construct(
+            'Secret key missing. It can be explictly provided, or it can be ' .
+            'auto-detected from the SNAPAUTH_SECRET_KEY environment variable.'
+        );
+    }
+}