fix Linux BLAS include path for manylinux containers

Add /usr/include/openblas to include_dirs on Linux so cblas.h resolves
in manylinux (CentOS-based) containers where openblas-devel installs
headers to /usr/include/openblas/ instead of /usr/include/.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: Transurgeon

setup.py

@@ -52,7 +52,7 @@ def finalize_options(self) -> None:
     blas_include_dirs = []
 elif system == "linux":
     blas_link_args = ["-lopenblas"]
-    blas_include_dirs = []
+    blas_include_dirs = ["/usr/include/openblas"]
 else:
     # Windows: OpenBLAS via vcpkg
     vcpkg_root = os.environ.get(