PhpDocRepository

The only PhpDoc capability the serializers need: read one doc by entity id, write one doc by entity id.

Fourteen files under Serialization/ used to name Storage\PhpDocStorage directly, while Storage\JsonParsedDataStorage names Serialization\EntitySerializerInterface — a cycle between the two namespaces. Only two of those fourteen ever called anything (getPhpDoc/setPhpDoc, both in SerializerHelperTrait); the other twelve mentioned the class purely in type declarations. So the cycle bought nothing and cost everything: a serializer unit test had to build a real PhpDocStorage — with a file path, lazy loading and a save() it must never call — to exercise a pure array transform.

Declared here rather than in Storage/ on purpose. The consumer owns the contract; Storage/ owns the implementation and keeps save()/load()/clear()/getAllPhpDocs() to itself, so no serializer can reach them by accident. Anything that needs the full storage lifecycle should keep depending on the concrete class.

StorageInterfaceSegregationTest::testSerializationDoesNotDependOnStorage() fails if the direct coupling comes back.