Consolidate settings normalization tests

tests/Service/Settings/SettingsSmtpGatewayTest.php

@@ -1,46 +0,0 @@
-<?php
-
-namespace MintyPHP\Tests\Service\Settings;
-
-use MintyPHP\Repository\Settings\SettingRepositoryInterface;
-use MintyPHP\Service\Settings\SettingsMetadataGateway;
-use MintyPHP\Service\Settings\SettingsSmtpGateway;
-use PHPUnit\Framework\TestCase;
-
-class SettingsSmtpGatewayTest extends TestCase
-{
-    public function testGetSmtpSecureReturnsNullForNone(): void
-    {
-        $settings = $this->createMock(SettingRepositoryInterface::class);
-        $settings->method('getValue')->willReturnCallback(static function (string $key): ?string {
-            if ($key === 'smtp_secure') {
-                return 'none';
-            }
-            return null;
-        });
-
-        $gateway = new SettingsSmtpGateway(new SettingsMetadataGateway($settings));
-        $this->assertNull($gateway->getSmtpSecure());
-    }
-
-    public function testSetSmtpSecureRejectsInvalidValue(): void
-    {
-        $settings = $this->createMock(SettingRepositoryInterface::class);
-        $settings->expects($this->never())->method('set');
-
-        $gateway = new SettingsSmtpGateway(new SettingsMetadataGateway($settings));
-        $this->assertFalse($gateway->setSmtpSecure('starttls'));
-    }
-
-    public function testSetSmtpHostPersistsNullForEmptyString(): void
-    {
-        $settings = $this->createMock(SettingRepositoryInterface::class);
-        $settings->expects($this->once())
-            ->method('set')
-            ->with('smtp_host', null, 'setting.smtp_host')
-            ->willReturn(true);
-
-        $gateway = new SettingsSmtpGateway(new SettingsMetadataGateway($settings));
-        $this->assertTrue($gateway->setSmtpHost('  '));
-    }
-}