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/ValueObjects/LocaleTest.php

@@ -0,0 +1,69 @@
+<?php
+
+declare(strict_types=1);
+
+use App\Domain\Cms\ValueObjects\Locale;
+
+describe('Locale', function () {
+    it('can be created from valid locale string', function () {
+        $locale = Locale::fromString('en');
+
+        expect($locale->toString())->toBe('en');
+        expect((string) $locale)->toBe('en');
+    });
+
+    it('accepts locale with region', function () {
+        $locale = Locale::fromString('en-US');
+
+        expect($locale->toString())->toBe('en-US');
+        expect($locale->getLanguage())->toBe('en');
+        expect($locale->getRegion())->toBe('US');
+    });
+
+    it('has factory methods for common locales', function () {
+        expect(Locale::english()->toString())->toBe('en');
+        expect(Locale::german()->toString())->toBe('de');
+        expect(Locale::french()->toString())->toBe('fr');
+        expect(Locale::spanish()->toString())->toBe('es');
+    });
+
+    it('extracts language from locale', function () {
+        expect(Locale::fromString('en')->getLanguage())->toBe('en');
+        expect(Locale::fromString('en-US')->getLanguage())->toBe('en');
+        expect(Locale::fromString('de-CH')->getLanguage())->toBe('de');
+    });
+
+    it('extracts region from locale with region', function () {
+        expect(Locale::fromString('en-US')->getRegion())->toBe('US');
+        expect(Locale::fromString('de-CH')->getRegion())->toBe('CH');
+    });
+
+    it('returns null for region when locale has no region', function () {
+        expect(Locale::fromString('en')->getRegion())->toBeNull();
+        expect(Locale::fromString('de')->getRegion())->toBeNull();
+    });
+
+    it('throws exception for invalid locale format', function () {
+        expect(fn () => Locale::fromString('invalid'))
+            ->toThrow(InvalidArgumentException::class, 'Invalid locale format');
+
+        expect(fn () => Locale::fromString('EN'))
+            ->toThrow(InvalidArgumentException::class);
+
+        expect(fn () => Locale::fromString('en-us'))
+            ->toThrow(InvalidArgumentException::class);
+    });
+
+    it('can compare two Locales for equality', function () {
+        $locale1 = Locale::fromString('en');
+        $locale2 = Locale::fromString('en');
+        $locale3 = Locale::fromString('de');
+
+        expect($locale1->equals($locale2))->toBeTrue();
+        expect($locale1->equals($locale3))->toBeFalse();
+
+        $locale4 = Locale::fromString('en-US');
+        expect($locale1->equals($locale4))->toBeFalse();
+    });
+});
+