Add new settings and cache repository files, update admin settings controller and templates

- Introduced new `SettingsRepository` and `CacheRepository` classes in the `autoload\Domain` namespace.
- Updated `SettingsController` in the `admin\Controllers` namespace to enhance settings management.
- Added new templates for settings in `admin\templates\settings` and `admin\templates\site`.
- Improved overall structure and organization of settings-related files.

tests/Unit/admin/Controllers/SettingsControllerTest.php

@@ -0,0 +1,66 @@
+<?php
+namespace Tests\Unit\admin\Controllers;
+
+use PHPUnit\Framework\TestCase;
+use admin\Controllers\SettingsController;
+use Domain\Settings\SettingsRepository;
+
+/**
+ * Testy dla SettingsController
+ *
+ * Kontroler używa SettingsRepository (DI).
+ * Cache czyszczony bezpośrednio przez \S::delete_dir() i \RedisConnection.
+ */
+class SettingsControllerTest extends TestCase
+{
+    private $mockSettingsRepository;
+    private $controller;
+
+    protected function setUp(): void
+    {
+        $this->mockSettingsRepository = $this->createMock(SettingsRepository::class);
+        $this->controller = new SettingsController($this->mockSettingsRepository);
+    }
+
+    public function testConstructorAcceptsRepository(): void
+    {
+        $controller = new SettingsController($this->mockSettingsRepository);
+        $this->assertInstanceOf(SettingsController::class, $controller);
+    }
+
+    public function testHasClearCacheMethod(): void
+    {
+        $this->assertTrue(method_exists($this->controller, 'clearCache'));
+    }
+
+    public function testHasClearCacheAjaxMethod(): void
+    {
+        $this->assertTrue(method_exists($this->controller, 'clearCacheAjax'));
+    }
+
+    public function testHasSaveMethod(): void
+    {
+        $this->assertTrue(method_exists($this->controller, 'save'));
+    }
+
+    public function testHasViewMethod(): void
+    {
+        $this->assertTrue(method_exists($this->controller, 'view'));
+    }
+
+    public function testIsNotAbstract(): void
+    {
+        $reflection = new \ReflectionClass($this->controller);
+        $this->assertFalse($reflection->isAbstract());
+    }
+
+    public function testActionMethodReturnTypes(): void
+    {
+        $reflection = new \ReflectionClass($this->controller);
+
+        $this->assertEquals('void', (string)$reflection->getMethod('clearCache')->getReturnType());
+        $this->assertEquals('void', (string)$reflection->getMethod('clearCacheAjax')->getReturnType());
+        $this->assertEquals('void', (string)$reflection->getMethod('save')->getReturnType());
+        $this->assertEquals('string', (string)$reflection->getMethod('view')->getReturnType());
+    }
+}