Add ValidJsonVerifier, that checks, that every normalizer correctly generated JSON-compatible values

[apfelbox]

Please ignore the CI, as I will bump deps + update CI in the next PR.

[Copilot]

Pull Request Overview

This PR introduces a debug-only mechanism to verify that normalized values are JSON-compatible, ensuring that only scalars, arrays, or empty objects are output. Key changes include:

• Addition of ValidJsonVerifier and InvalidJsonElement classes to detect and report invalid JSON types.
• Updates to SimpleNormalizer to invoke the verifier when in debug mode.
• Tests in SimpleNormalizerTest covering enabled/disabled verifier and invalid-value exceptions.
• Configuration update to pass the debug flag to SimpleNormalizer.

Reviewed Changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
tests/Normalizer/SimpleNormalizerTest.php	New tests for JSON verifier enabled/disabled and error cases
src/Normalizer/Validator/ValidJsonVerifier.php	Implementation of JSON-type checker
src/Normalizer/Validator/InvalidJsonElement.php	Data holder for reporting invalid JSON elements
src/Normalizer/SimpleNormalizer.php	Hook into verifier in public API methods
src/Exception/IncompleteNormalizationException.php	New exception for incomplete normalization
config/services.yaml	Pass %kernel.debug% to SimpleNormalizer
CHANGELOG.md	Release notes for 1.4.0 feature

Comments suppressed due to low confidence (3)

config/services.yaml:14

• The SimpleNormalizer service is configured with $isDebug but the validJsonVerifier argument is not wired. As written, debug mode won’t actually inject the verifier. Consider adding:

      $validJsonVerifier: '@Torr\SimpleNormalizer\Normalizer\Validator\ValidJsonVerifier'

        $isDebug: '%kernel.debug%'

src/Normalizer/Validator/ValidJsonVerifier.php:38

• The @return annotation is inaccurate: this method returns InvalidJsonElement|null, not a generic mixed. Please update it to @return InvalidJsonElement|null for clarity.

	 * @return mixed Returns null if everything is valid, otherwise the invalid value.

tests/Normalizer/SimpleNormalizerTest.php:64

• [nitpick] This test only covers the normalize method. To ensure full coverage, consider data-driving this case for normalizeArray and normalizeMap, similar to the enabled tests.

	public function testJsonVerifierDisabled () : void