add-torch-shapes-example

You are importing a PyTorch model into Pyrefly's example corpus at tensor-shapes/pyrefly-torch-stubs/examples/. This is the contribution case the porting skill describes: these ports are tested reference material that others read to learn the patterns, so produce its fuller deliverable — paste every artifact (audit table, per-local reveal_type dumps, typed-interface receipts, exhaustive assert_type coverage, completion report) in full, not just the annotated model.

Why these ports matter. They demonstrate what happens when you write a real PyTorch model with tensor shape types. Record the upstream repository and revision, exact files or dependency closure, concrete configuration, entry points, and train/eval/cache/export modes included. "Complete" means complete inside that declared boundary; list any omitted wrapper or mode rather than calling a representative core the full upstream model.