Package rubydex MCP executable in gem

.gitignore

@@ -22,3 +22,4 @@ THIRD_PARTY_LICENSES.html
 rust/THIRD_PARTY_LICENSES.html
 lib/rubydex/*.dylib
 lib/rubydex/*.so
+lib/rubydex/bin/

exe/rubydex_mcp

@@ -0,0 +1,17 @@
+#!/usr/bin/env ruby
+# frozen_string_literal: true
+
+require "rbconfig"
+
+host_os = RbConfig::CONFIG.fetch("host_os")
+executable = host_os.match?(/mswin|mingw|cygwin/) ? "rubydex_mcp.exe" : "rubydex_mcp"
+binary = File.expand_path("../lib/rubydex/bin/#{executable}", __dir__)
+
+unless File.executable?(binary)
+  abort(<<~MESSAGE.chomp)
+    rubydex_mcp is not available at #{binary}.
+    Install a precompiled rubydex gem, or reinstall rubydex with Cargo available so the MCP executable can be built locally.
+  MESSAGE
+end
+
+exec(binary, *ARGV)

ext/rubydex/extconf.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require "mkmf"
+require "fileutils"
 require "pathname"
 
 unless system("cargo", "--version", out: File::NULL, err: File::NULL)
@@ -81,6 +82,12 @@
 end
 
 lib_dir = gem_dir.join("lib").join("rubydex")
+mcp_bin_dir = lib_dir.join("bin")
+FileUtils.mkdir_p(mcp_bin_dir)
+
+mcp_executable = Gem.win_platform? ? "rubydex_mcp.exe" : "rubydex_mcp"
+mcp_src = target_dir.join(mcp_executable)
+mcp_dst = mcp_bin_dir.join(mcp_executable)
 
 copy_dylib_commands = if Gem.win_platform?
   ""
@@ -107,6 +114,7 @@
   .rust_built: $(RUST_SRCS)
   \t#{cargo_command} || (echo "Compiling Rust failed" && exit 1)
   \t$(COPY) #{bindings_path} #{__dir__}
+  \t$(COPY) #{mcp_src} #{mcp_dst}
   \ttouch $@
 
   compile_rust: .rust_built

rubydex.gemspec

@@ -28,6 +28,7 @@ Gem::Specification.new do |spec|
 
   if ENV["RELEASE"]
     spec.files << "THIRD_PARTY_LICENSES.html"
+    spec.files << "lib/rubydex/bin/#{Gem.win_platform? ? "rubydex_mcp.exe" : "rubydex_mcp"}"
     if RUBY_PLATFORM.include?("darwin")
       spec.files << "lib/rubydex/librubydex_sys.dylib"
     elsif RUBY_PLATFORM.include?("linux")