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/Cms/Rendering/BlockRendererRegistryTest.php

@@ -0,0 +1,76 @@
+<?php
+
+declare(strict_types=1);
+
+use App\Domain\Cms\Rendering\BlockRendererInterface;
+use App\Domain\Cms\Rendering\BlockRendererRegistry;
+use App\Domain\Cms\Rendering\HeroBlockRenderer;
+use App\Domain\Cms\Rendering\TextBlockRenderer;
+
+describe('BlockRendererRegistry', function () {
+    it('can register renderer for specific type', function () {
+        $registry = new BlockRendererRegistry();
+        $renderer = new HeroBlockRenderer();
+
+        $registry->registerForType('hero', $renderer);
+
+        expect($registry->hasRenderer('hero'))->toBeTrue();
+        expect($registry->getRenderer('hero'))->toBe($renderer);
+    });
+
+    it('can register multiple renderers', function () {
+        $registry = new BlockRendererRegistry();
+        $heroRenderer = new HeroBlockRenderer();
+        $textRenderer = new TextBlockRenderer();
+
+        $registry->registerForType('hero', $heroRenderer);
+        $registry->registerForType('text', $textRenderer);
+
+        expect($registry->getRenderer('hero'))->toBe($heroRenderer);
+        expect($registry->getRenderer('text'))->toBe($textRenderer);
+    });
+
+    it('returns null for unregistered block type', function () {
+        $registry = new BlockRendererRegistry();
+
+        expect($registry->getRenderer('unknown'))->toBeNull();
+        expect($registry->hasRenderer('unknown'))->toBeFalse();
+    });
+
+    it('can find renderer by supports method', function () {
+        $registry = new BlockRendererRegistry();
+        $heroRenderer = new HeroBlockRenderer();
+
+        $registry->register($heroRenderer);
+
+        $found = $registry->getRenderer('hero');
+        expect($found)->toBe($heroRenderer);
+    });
+
+    it('can get all registered renderers', function () {
+        $registry = new BlockRendererRegistry();
+        $heroRenderer = new HeroBlockRenderer();
+        $textRenderer = new TextBlockRenderer();
+
+        $registry->registerForType('hero', $heroRenderer);
+        $registry->registerForType('text', $textRenderer);
+
+        $all = $registry->getAllRenderers();
+
+        expect($all)->toHaveCount(2);
+        expect($all['hero'])->toBe($heroRenderer);
+        expect($all['text'])->toBe($textRenderer);
+    });
+
+    it('overwrites renderer when registering same type twice', function () {
+        $registry = new BlockRendererRegistry();
+        $renderer1 = new HeroBlockRenderer();
+        $renderer2 = new HeroBlockRenderer();
+
+        $registry->registerForType('hero', $renderer1);
+        $registry->registerForType('hero', $renderer2);
+
+        expect($registry->getRenderer('hero'))->toBe($renderer2);
+    });
+});
+