Exclude CLAUDE.md and docs/ from packaged gem files

spec.files globbed every file on disk, so AI-assistant instructions
and session notes ended up shipped inside net-ping-2.1.0, breaking
downstream RPM packaging (issue #46).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

Author: eitoball

net-ping.gemspec

@@ -9,7 +9,9 @@ Gem::Specification.new do |spec|
   spec.homepage  = 'https://github.com/chernesk/net-ping'
   spec.summary   = 'A ping interface for Ruby.'
   spec.test_file = 'test/test_net_ping.rb'
-  spec.files     = Dir['**/*'].reject { |f| f.include?('git') || File.extname(f) == '.gem' }
+  spec.files     = Dir['**/*'].reject do |f|
+    f.include?('git') || File.extname(f) == '.gem' || f == 'CLAUDE.md' || f.start_with?('docs/')
+  end
   spec.metadata = {
     'bug_tracker_uri' => "#{spec.homepage}/issues",
     'changelog_uri' => "#{spec.homepage}/blob/master/CHANGES",

test/test_net_ping_gem_packaging.rb

@@ -78,6 +78,16 @@ def test_gem_create_excludes_generated_artifacts_from_spec_files_and_keeps_bundl
     delete_files(built_gem_files)
   end
 
+  def test_gem_create_excludes_non_distributable_project_files_from_spec_files
+    load_specifications.each do |path, spec|
+      non_distributable = spec.files.select do |f|
+        f == 'CLAUDE.md' || f.start_with?('docs/')
+      end
+
+      assert_equal([], non_distributable, path)
+    end
+  end
+
   def test_gem_check_uses_fixed_expectations_instead_of_loaded_specifications
     stdout, stderr, status = run_rake('clean', 'gem:create')