langchain-typesafe: recursive `State` alias leaves input schema unresolvable
The `TypeSafeClassifier` input schema generation fails with `PydanticUserError` because the private recursive `_StateValue` type alias is not resolvable in the dynamically created `TypeSafeClassifierInput` model namespace. This breaks `get_input_jsonschema()`, `as_tool()`, schemaful graph serialization, and Runnable composition schema introspection.
