Expand description
Non-generic Output handle threaded through DSL method chains.
Per docs/API_DESIGN.md §4 + docs/IR_AND_DSL.md Part 6. The DSL
is non-generic across languages - type metadata rides on
&'static TypeNode, NOT a PhantomData<T> tag. Identity is the
name: String (the ONNX value name in FunctionProto.input /
NodeProto.input / NodeProto.output); the wire-level type
identity rides on the TypeNode reference.