Fix tool name method to strip unsupported characters for OpenAI (#28)

Updates the `name` method in the `Tool` class to strip unsupported
characters and replace them with the closest characters as OpenAI only supports
tool names with `/a-zA-Z0-9_-/+`

Author: stevegeek

lib/ruby_llm/tool.rb

@@ -50,6 +50,9 @@ def parameters
 
     def name
       self.class.name
+          .unicode_normalize(:nfkd)
+          .encode('ASCII', replace: '')
+          .gsub(/[^a-zA-Z0-9_-]/, '-')
           .gsub(/([A-Z]+)([A-Z][a-z])/, '\1_\2')
           .gsub(/([a-z\d])([A-Z])/, '\1_\2')
           .downcase

spec/ruby_llm/tool_spec.rb

@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe RubyLLM::Tool do
+  describe '#name' do
+    it 'converts class name to snake_case and removes _tool suffix' do
+      stub_const('SampleTool', Class.new(described_class))
+      expect(SampleTool.new.name).to eq('sample')
+    end
+
+    # rubocop:disable Naming/AsciiIdentifiers
+
+    it 'normalizes class name Unicode characters to ASCII' do
+      stub_const('SàmpleTòol', Class.new(described_class))
+      expect(SàmpleTòol.new.name).to eq('sample')
+    end
+
+    it 'handles class names with unsupported characters' do
+      stub_const('SampleΨTool', Class.new(described_class))
+      expect(SampleΨTool.new.name).to eq('sample')
+    end
+
+    # rubocop:enable Naming/AsciiIdentifiers
+
+    it 'handles class names without Tool suffix' do
+      stub_const('AnotherSample', Class.new(described_class))
+      expect(AnotherSample.new.name).to eq('another_sample')
+    end
+
+    it 'strips :: for class in module namespace' do
+      stub_const('TestModule::SampleTool', Class.new(described_class))
+      expect(TestModule::SampleTool.new.name).to eq('test_module--sample')
+    end
+  end
+end