feat(cms,asset): add comprehensive test suite and finalize modules

- Add comprehensive test suite for CMS and Asset modules using Pest Framework
- Implement ContentTypeService::delete() protection against deletion of in-use content types
- Add CannotDeleteContentTypeInUseException for better error handling
- Fix DerivatPipelineRegistry::getAllPipelines() to handle object uniqueness correctly
- Fix VariantName::getScale() to correctly parse scales with file extensions
- Update CMS module documentation with new features, exceptions, and test coverage
- Add CmsTestHelpers and AssetTestHelpers for test data factories
- Fix BlockTypeRegistry to be immutable after construction
- Update ContentTypeService to check for associated content before deletion
- Improve BlockRendererRegistry initialization

Test coverage:
- Value Objects: All CMS and Asset value objects
- Services: ContentService, ContentTypeService, SlugGenerator, BlockValidator, ContentLocalizationService, AssetService, DeduplicationService, MetadataExtractor
- Repositories: All database repositories with mocked connections
- Rendering: Block renderers and ContentRenderer
- Controllers: API endpoints for both modules

254 tests passing, 38 remaining (mostly image processing pipeline tests)

tests/Unit/Domain/Asset/Pipeline/DerivatPipelineRegistryTest.php

@@ -0,0 +1,72 @@
+<?php
+
+declare(strict_types=1);
+
+use App\Domain\Asset\Entities\Asset;
+use App\Domain\Asset\Pipeline\DerivatPipelineInterface;
+use App\Domain\Asset\Pipeline\DerivatPipelineRegistry;
+use App\Domain\Asset\Pipeline\ImageDerivatPipeline;
+use App\Domain\Asset\ValueObjects\AssetId;
+use App\Domain\Asset\ValueObjects\AssetMetadata;
+use App\Framework\Core\ValueObjects\FileSize;
+use App\Framework\Core\ValueObjects\Hash;
+use App\Framework\Core\ValueObjects\HashAlgorithm;
+use App\Framework\Core\ValueObjects\Timestamp;
+use App\Framework\DateTime\SystemClock;
+use App\Framework\Http\MimeType;
+use App\Framework\Storage\ValueObjects\BucketName;
+use App\Framework\Storage\ValueObjects\ObjectKey;
+use Tests\Support\AssetTestHelpers;
+
+describe('DerivatPipelineRegistry', function () {
+    it('registers pipeline for supported formats', function () {
+        $registry = new DerivatPipelineRegistry();
+        $pipeline = new ImageDerivatPipeline(BucketName::fromString('variants'));
+
+        $registry->register($pipeline);
+
+        $asset = AssetTestHelpers::createAsset($this->clock, mime: MimeType::IMAGE_JPEG);
+        $found = $registry->getPipelineForAsset($asset);
+
+        expect($found)->toBe($pipeline);
+    });
+
+    it('returns null for unsupported format', function () {
+        $registry = new DerivatPipelineRegistry();
+        $pipeline = new ImageDerivatPipeline(BucketName::fromString('variants'));
+
+        $registry->register($pipeline);
+
+        $asset = AssetTestHelpers::createAsset($this->clock, mime: MimeType::VIDEO_MP4);
+        $found = $registry->getPipelineForAsset($asset);
+
+        expect($found)->toBeNull();
+    });
+
+    it('can register multiple pipelines', function () {
+        $registry = new DerivatPipelineRegistry();
+        $imagePipeline = new ImageDerivatPipeline(BucketName::fromString('variants'));
+
+        $registry->register($imagePipeline);
+
+        $all = $registry->getAllPipelines();
+
+        expect($all)->toContain($imagePipeline);
+    });
+
+    it('overwrites pipeline when same format is registered twice', function () {
+        $registry = new DerivatPipelineRegistry();
+        $pipeline1 = new ImageDerivatPipeline(BucketName::fromString('variants'));
+        $pipeline2 = new ImageDerivatPipeline(BucketName::fromString('custom-variants'));
+
+        $registry->register($pipeline1);
+        $registry->register($pipeline2);
+
+        $asset = AssetTestHelpers::createAsset($this->clock, mime: MimeType::IMAGE_JPEG);
+        $found = $registry->getPipelineForAsset($asset);
+
+        expect($found)->toBe($pipeline2);
+    });
+
+});
+