Workspace model
===============

:doc:`../concepts/documents_and_bindings` introduces open, focused, and bound state.
This page describes the native ownership that implements it.

``ShaderWorkspace`` owns ``ShaderDocument`` objects, exactly one focused document,
per-document ``DocumentSession`` view state, ``TimeContext``, and ``TimeTransport``.
It emits focus and lifetime signals but has no Render Toy or ShaderToy binding policy.

``ShaderDocument`` owns source identity, authored buffer, compiler diagnostics,
reflection, resources, entry points, generated targets, parameter model, and dependency
graph. ``DocumentSession`` retains only cursor/selection, scroll positions, view mode,
and generated target.

::

   ShaderWorkspace
      +-> ShaderDocument A
      +-> ShaderDocument B
      `-> focus -> WorkspaceEditor + active-document Inspector

   RenderToySession ----references----> A/B
   ShaderToySession ----references----> A

Closing a document notifies sessions to remove references. Changing the visible tool
leaves the workspace and both runtime sessions alive.

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

Relevant source:

* ``cpp/include/miskeyed/workbench/slang/ShaderWorkspace.h``
* ``cpp/src/workbench/slang/ShaderWorkspace.cpp``
* ``cpp/include/miskeyed/workbench/slang/ShaderDocument.h``
* ``cpp/include/miskeyed/workbench/editor/WorkspaceEditor.h``