Repair Windows wheels with delvewheel to bundle openblas.dll (#17)

Windows wheels shipped a .pyd that dynamically links openblas.dll from
vcpkg, but cibuildwheel has no default repair step on Windows (unlike
auditwheel/delocate), so the DLL was never bundled and every import
failed with 'DLL load failed'. Run delvewheel to vendor the DLL into
the wheel, and add a smoke-test import on all platforms so a broken
wheel can't publish again.

Fixes #15

Co-authored-by: Transurgeon <peter.zijie@gmail.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

Author: 3 people

.github/workflows/build-and-publish.yml

@@ -65,8 +65,11 @@ jobs:
           CIBW_ARCHS_MACOS: "x86_64 universal2"
           CIBW_ARCHS_LINUX: "auto aarch64"
           CIBW_BEFORE_BUILD_LINUX: "yum install -y openblas-devel || apt-get install -y libopenblas-dev"
-          CIBW_BEFORE_BUILD_WINDOWS: "vcpkg install openblas:x64-windows"
+          CIBW_BEFORE_BUILD_WINDOWS: "pip install delvewheel && vcpkg install openblas:x64-windows"
           CIBW_ENVIRONMENT_WINDOWS: "CMAKE_TOOLCHAIN_FILE=C:/vcpkg/scripts/buildsystems/vcpkg.cmake"
+          # Bundle openblas.dll into the wheel (auditwheel/delocate handle this on Linux/macOS)
+          CIBW_REPAIR_WHEEL_COMMAND_WINDOWS: "delvewheel repair -w {dest_dir} {wheel} --add-path C:/vcpkg/installed/x64-windows/bin"
+          CIBW_TEST_COMMAND: python -c "import sparsediffpy"
       - name: Check wheels
         shell: bash
         run: |