just redo all of it from scratch

lib/mcp/shared/prompt/message.rb

@@ -0,0 +1,19 @@
+# typed: strict
+# frozen_string_literal: true
+
+module MCP
+  class Prompt
+    class Message
+      attr_reader :role, :content
+
+      def initialize(role:, content:)
+        @role = role
+        @content = content
+      end
+
+      def to_h
+        { role:, content: content.to_h }.compact
+      end
+    end
+  end
+end