Ownership and lifetime
======================

Slang owns language semantics, imports, program composition, reflection, and backend
code generation. Workbench owns authored/editor state, document lifetime, dependency
identity, parameter presentation, tool bindings, and render consumption. Qt/QRhi owns
the graphics abstraction; C++ coordinates native lifetime and submission.

::

   ShaderWorkspace owns ShaderDocument objects and shared time
   Tool sessions reference documents and select capabilities
   SlangRhiWidget/RenderPass consume compiled products through QRhi

A binding is not document ownership. Python exposure is not render-core ownership.

Implementation
--------------

Start with ``ShaderWorkspace.h``, ``ShaderDocument.h``, tool ``*Session.h`` files,
and ``rendering/RenderPass.h``.