refactor: update stats/base/snanvariancepn native addon from C++ to C

lib/node_modules/@stdlib/stats/base/snanvariancepn/include.gypi

@@ -36,7 +36,7 @@
 
     # Source files:
     'src_files': [
-      '<(src_dir)/addon.cpp',
+      '<(src_dir)/addon.c',
       '<!@(node -e "var arr = require(\'@stdlib/utils/library-manifest\')(\'./manifest.json\',{},{\'basedir\':process.cwd(),\'paths\':\'posix\'}).src; for ( var i = 0; i < arr.length; i++ ) { console.log( arr[ i ] ); }")',
     ],
 

lib/node_modules/@stdlib/stats/base/snanvariancepn/manifest.json

@@ -1,5 +1,7 @@
 {
-  "options": {},
+  "options": {
+    "task": "build"
+  },
   "fields": [
     {
       "field": "src",
@@ -24,6 +26,42 @@
   ],
   "confs": [
     {
+      "task": "build",
+      "src": [
+        "./src/snanvariancepn.c"
+      ],
+      "include": [
+        "./include"
+      ],
+      "libraries": [
+        "-lm"
+      ],
+      "libpath": [],
+      "dependencies": [
+        "@stdlib/stats/base/snanvariancepn",
+        "@stdlib/napi/export",
+        "@stdlib/napi/argv",
+        "@stdlib/napi/argv-int64",
+        "@stdlib/napi/argv-strided-float32array",
+        "@stdlib/napi/create-double"
+      ]
+    },
+    {
+      "task": "benchmark",
+      "src": [
+        "./src/snanvariancepn.c"
+      ],
+      "include": [
+        "./include"
+      ],
+      "libraries": [
+        "-lm"
+      ],
+      "libpath": [],
+      "dependencies": []
+    },
+    {
+      "task": "examples",
       "src": [
         "./src/snanvariancepn.c"
       ],

lib/node_modules/@stdlib/stats/base/snanvariancepn/src/addon.c

@@ -0,0 +1,46 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2025 The Stdlib Authors.
+*
+* Licensed under the Apache License, Version 2.0 (the "License");
+* you may not use this file except in compliance with the License.
+* You may obtain a copy of the License at
+*
+*    http://www.apache.org/licenses/LICENSE-2.0
+*
+* Unless required by applicable law or agreed to in writing, software
+* distributed under the License is distributed on an "AS IS" BASIS,
+* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+* See the License for the specific language governing permissions and
+* limitations under the License.
+*/
+
+#include "stdlib/stats/base/snanvariancepn.h"
+#include "stdlib/napi/export.h"
+#include "stdlib/napi/argv.h"
+#include "stdlib/napi/argv_int64.h"
+#include "stdlib/napi/argv_double.h"
+#include "stdlib/napi/argv_strided_float64array.h"
+#include "stdlib/napi/create_double.h"
+#include <node_api.h>
+
+/**
+* Receives JavaScript callback invocation data.
+*
+* @param env    environment under which the function is invoked
+* @param info   callback data
+* @return       Node-API value
+*/
+static napi_value addon( napi_env env, napi_callback_info info ) {
+	STDLIB_NAPI_ARGV( env, info, argv, argc, 5 );
+	STDLIB_NAPI_ARGV_INT64( env, N, argv, 0 );
+	STDLIB_NAPI_ARGV_INT64( env, stride, argv, 4 );
+	STDLIB_NAPI_ARGV_DOUBLE( env, mean, argv, 1 );
+	STDLIB_NAPI_ARGV_DOUBLE( env, correction, argv, 2 );
+	STDLIB_NAPI_ARGV_STRIDED_FLOAT64ARRAY( env, X, N, stride, argv, 3 );
+	STDLIB_NAPI_CREATE_DOUBLE( env, stdlib_strided_dvarmpn( N, mean, correction, X, stride ), v );
+	return v;
+}
+
+STDLIB_NAPI_MODULE_EXPORT_FCN( addon )