Fix test suite for contributte/tester migration

This commit fixes all test failures after migrating to contributte/tester:

Test Bootstrap:
- Replaced Ninjify\Nunjuck\Environment with Contributte\Tester\Environment
- Simplified setup to use Environment::setup(__DIR__)

Test Files:
- Updated DefaultFile.phpt to use Contributte\Tester\Toolkit
- Fixed FileUploadExtension.phpt namespace references:
  - Zet\FileUpload\Filter\ImageFilter → Contributte\FileUpload\Filter\ImageFilter
  - Zet\FileUpload\Template\Renderer\Bootstrap4Renderer → Contributte\FileUpload\Template\Renderer\Bootstrap4Renderer
  - Tests\Fixtures\Renderer\InvalidRenderer → Tests\Fixtures\Template\Renderer\InvalidRenderer

PSR-4 Compliance:
- Renamed tests/toolkit → tests/Toolkit (for Tests\Toolkit namespace)
- Renamed tests/fixtures → tests/Fixtures (for Tests\Fixtures namespace)
- This allows PSR-4 autoloading to work correctly

Code Fixes:
- Made DefaultFile properties nullable with default null values
- Fixed ValidUploadModel::rename() return type from void to mixed
  to match parent BaseUploadModel::rename() signature

All tests passing: ✅ 5/5
All QA checks passing: ✅ PHPStan Level 8 + CodeSniffer

Author: claude

src/Model/DefaultFile.php

@@ -23,17 +23,17 @@ class DefaultFile
 	/**
 	 * Odkaz na náhled obrázku.
 	 */
-	private string $preview;
+	private ?string $preview = null;
 
 	/**
 	 * Název souboru.
 	 */
-	private string $filename;
+	private ?string $filename = null;
 
 	/**
 	 * Identifikátor souboru sloužící pro jeho smazání.
 	 */
-	private mixed $identifier;
+	private mixed $identifier = null;
 
 	/**
 	 * @return array<mixed>
@@ -47,22 +47,22 @@ public function toArray(): array
 		];
 	}
 
-	public function getPreview(): string
+	public function getPreview(): ?string
 	{
 		return $this->preview;
 	}
 
-	public function setPreview(string $preview): void
+	public function setPreview(?string $preview): void
 	{
 		$this->preview = $preview;
 	}
 
-	public function getFilename(): string
+	public function getFilename(): ?string
 	{
 		return $this->filename;
 	}
 
-	public function setFilename(string $filename): void
+	public function setFilename(?string $filename): void
 	{
 		$this->filename = $filename;
 	}

tests/fixtures/Filter/InvalidFilter.php tests/Fixtures/Filter/InvalidFilter.phptests/fixtures/Filter/InvalidFilter.php renamed to tests/Fixtures/Filter/InvalidFilter.php

@@ -14,9 +14,11 @@ public function remove(mixed $uploaded): void
 		FileSystem::delete($uploaded[0] . '/' . $uploaded[1]);
 	}
 
-	public function rename(mixed $upload, string $newName): void
+	public function rename(mixed $upload, string $newName): mixed
 	{
 		FileSystem::rename($upload[0] . '/' . $upload[1], $upload[0] . '/' . $newName);
+
+		return null;
 	}
 
 	/**

tests/fixtures/Filter/ValidFilter.php tests/Fixtures/Filter/ValidFilter.phptests/fixtures/Filter/ValidFilter.php renamed to tests/Fixtures/Filter/ValidFilter.php

@@ -1,13 +1,10 @@
 <?php declare(strict_types = 1);
 
-use Ninjify\Nunjuck\Environment;
+use Contributte\Tester\Environment;
 
 if (@!include __DIR__ . '/../vendor/autoload.php') {
 	echo 'Install Nette Tester using `composer update --dev`';
 	exit(1);
 }
 
-// Configure environment
-Environment::setupTester();
-Environment::setupTimezone();
-Environment::setupVariables(__DIR__);
+Environment::setup(__DIR__);