chore(stats/halfnormal): add missing license headers

Author: anujmishra03

lib/node_modules/@stdlib/stats/base/dists/halfnormal/README.md

@@ -1,7 +1,26 @@
+<!--
+@license Apache-2.0
+
+Copyright (c) 2016-2025 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.
+-->
+
 # Half-Normal Distribution (PDF only)
 
 > Probability Density Function (PDF) of the half-normal distribution.
 
+
 ## Usage
 
 ```javascript

lib/node_modules/@stdlib/stats/base/dists/halfnormal/lib/index.js

@@ -0,0 +1,17 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2016-2025 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.
+*/

lib/node_modules/@stdlib/stats/base/dists/halfnormal/lib/pdf.js

@@ -1,3 +1,24 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2016-2025 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.
+*/
+
+
+
+
 'use strict';
 
 var sqrt = require('@stdlib/math/base/special/sqrt');

lib/node_modules/@stdlib/stats/base/dists/halfnormal/test/test.pdf.js

@@ -1,3 +1,23 @@
+/**
+* @license Apache-2.0
+*
+* Copyright (c) 2016-2025 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.
+*/
+
+
+
 'use strict';
 
 var tape = require('tape');