Add Model/Repository postfix to all class and file names

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/repository/message_board_repository.rb

@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+require 'csv'
+require 'time'
+require 'fileutils'
+require_relative '../model/message_model'
+
+class MessageBoardRepository
+  def initialize(path)
+    @path     = path
+    @messages = []
+    @mu       = Mutex.new
+    load_csv
+  end
+
+  def append(username, text)
+    msg = MessageModel.new(Time.now.strftime('%m-%d %H:%M'), username, text)
+    @mu.synchronize do
+      @messages << msg
+      FileUtils.mkdir_p(File.dirname(@path))
+      CSV.open(@path, 'a') { |csv| csv << [msg.timestamp, msg.username, msg.text] }
+    end
+    msg
+  end
+
+  def last(n = 30)
+    @mu.synchronize { @messages.last(n) }
+  end
+
+  def count
+    @mu.synchronize { @messages.size }
+  end
+
+  private
+
+  def load_csv
+    return unless File.exist?(@path)
+    CSV.foreach(@path) { |row| @messages << MessageModel.new(*row) }
+  rescue => e
+    warn "MessageBoardRepository load error: #{e}"
+  end
+end