Bug: test_reshape_openvino_npu_quick hangs in EPChecker.check_compile (env/driver issue, not code regression)

Symptom

tests/integration/analyze/runtime_checker/test_reshape_openvino.py::test_reshape_openvino_npu_quick hangs indefinitely on a developer machine that has an Intel NPU + OpenVINO drivers installed (i.e. expected to be a green path).

The hang traces to:

tests/integration/analyze/runtime_checker/test_helper.py:63   list(test_results_iter)
src/winml/modelkit/pattern/op_input_gen/op_input_gen.py:1546  check_on_ep
src/winml/modelkit/analyze/runtime_checker/runner.py:294      future.result(timeout=self.timeout_sec)

The worker subprocess never returns from EPChecker.check_compile for OpenVINOExecutionProvider on OrtHardwareDeviceType.NPU. The internal timeout eventually fires; faulthandler dumps the worker stack and pytest exits non-zero.

Reproduction

uv run pytest tests/integration/analyze/runtime_checker/test_reshape_openvino.py::test_reshape_openvino_npu_quick -v --timeout=180

Bisection — not an in-tree regression

Test reproduces the hang back to the first public commit on this hardware, so the issue is not a code regression. The hang is upstream of the timeout/kill code path that #357 modified — future.result is waiting on a worker that is stuck inside the actual OpenVINO compile call.

Hypothesis — environment / driver layer

The OpenVINO NPU Compile call hangs in the worker subprocess. Likely candidates:

• OpenVINO Python package version mismatched with the installed NPU driver
• NPU driver state (e.g. residual context from a previous crashed run)
• ORT NPU device enumeration interaction

Suggested investigation

1. uv pip show openvino — record version on the affected machine
2. Compile a minimal Reshape-only ONNX model directly via the OpenVINO Python API targeting NPU — does the standalone path also hang?
3. Reproduce on a CI agent with NPU — if it also hangs there, this is an OpenVINO/driver compatibility issue at the EPChecker.check_compile layer; file upstream.
4. If only reproducible on developer boxes, document the required driver / OpenVINO versions in the contributing guide.

Out of scope for this issue

This is not about ModelKit's timeout handling code (that path is fine; the test never gets that far). It is about why the actual NPU compile call doesn't return.