Add 5 E2E tests for session execution mode: 2 unit tests for code
generation structure and 3 runtime tests that exercise the full
ComfyUI pipeline (oneshot, session single run, session multi-run).
Fix close() method signature in generated session code to use
"bool | None = None" instead of "bool = True" for consistency
with the actual generated output.
Move generated torch imports until after add_extra_model_paths runs so exported scripts do not trigger ComfyUI's early-torch warning during startup. Update export assertions and checked-in runtime generated fixtures to match the new main() ordering.
Peyton DeNiro