feat: add numpy/numpy_py.h umbrella for pybind11 wrappers

Mirrors numpy/numpy.h for the C++ core — single include for all _py.h modules:
  #include <numpycpp/numpy/numpy_py.h>

Author: peng.li24

numpy/numpy_py.h

@@ -0,0 +1,28 @@
+// ════════════════════════════════════════════════════════════════════════════
+//  numpycpp — numpy/numpy_py.h                           [PUBLIC HEADER]
+//
+//  Single umbrella header — includes all pybind11 wrapper modules.
+//
+//  Usage:
+//      #include "numpy/numpy_py.h"
+//
+//  Prerequisite:
+//      #include <pybind11/pybind11.h>
+//      #include <pybind11/stl.h>
+//
+//  Or include individual wrapper modules as needed:
+//      #include "numpy/init_py.h"         // zeros_like, ones_like, full, …
+//      #include "numpy/elementwise_py.h"  // sqrt, exp, sin, astype, …
+//      #include "numpy/reduce_py.h"       // sum, mean, std, var, cumsum, …
+//      #include "numpy/manipulation_py.h" // transpose, take, slice, put, …
+//      #include "numpy/io_py.h"           // isin, interp, unwrap, asarray, …
+//      #include "numpy/linalg_py.h"       // dot, norm, matmul, einsum
+// ════════════════════════════════════════════════════════════════════════════
+#pragma once
+
+#include "init_py.h"
+#include "elementwise_py.h"
+#include "reduce_py.h"
+#include "manipulation_py.h"
+#include "io_py.h"
+#include "linalg_py.h"

tests/module.cpp

@@ -4,12 +4,7 @@
 
 #include <pybind11/pybind11.h>
 #include <pybind11/stl.h>
-#include "numpy/init_py.h"
-#include "numpy/elementwise_py.h"
-#include "numpy/reduce_py.h"
-#include "numpy/manipulation_py.h"
-#include "numpy/io_py.h"
-#include "numpy/linalg_py.h"
+#include "numpy/numpy_py.h"
 
 namespace py = pybind11;