Add missing exceptions

Author: nthndnn

src/Exceptions/InvalidStateMachineConfigurationException.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace NathanDunn\StateHistory\Exceptions;
+
+use Exception;
+
+class InvalidStateMachineConfigurationException extends Exception
+{
+    public function __construct(
+        string $field,
+        mixed $config,
+        ?string $modelClass = null
+    ) {
+        $modelInfo = $modelClass ? " for {$modelClass}" : '';
+        $configType = is_object($config) ? get_class($config) : gettype($config);
+        $message = "Invalid state machine configuration for field '{$field}'{$modelInfo}. " .
+                  "Expected string or array with 'machine' key, got {$configType}.";
+
+        parent::__construct($message);
+    }
+}

src/Exceptions/NoStateMachineConfiguredException.php

@@ -0,0 +1,18 @@
+<?php
+
+namespace NathanDunn\StateHistory\Exceptions;
+
+use Exception;
+
+class NoStateMachineConfiguredException extends Exception
+{
+    public function __construct(
+        string $field,
+        ?string $modelClass = null
+    ) {
+        $modelInfo = $modelClass ? " for {$modelClass}" : '';
+        $message = "No state machine configured for field '{$field}'{$modelInfo}.";
+
+        parent::__construct($message);
+    }
+}