Introduce model/ and repository/ structure under lib/

Models: Message, WikiPage, Game (typed structs instead of raw hashes)
Repositories: MessageBoard, OnlineUsers, WikiClient, CatalogClient
bbs.rb uses attribute access (page.title, game.play_path, …) throughout

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

lib/repository/catalog.rb

@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+require 'net/http'
+require 'json'
+require 'uri'
+require_relative '../model/game'
+
+class CatalogClient
+  API_URL   = 'https://games.teletype.hu/api/software'
+  GAMES_URL = 'https://games.teletype.hu'
+
+  def fetch
+    uri  = URI(API_URL)
+    http = Net::HTTP.new(uri.host, uri.port)
+    http.use_ssl      = uri.scheme == 'https'
+    http.open_timeout = 12
+    http.read_timeout = 12
+    data    = JSON.parse(http.get(uri.path).body)
+    entries = data.is_a?(Hash) ? (data['softwares'] || []) : data
+    entries.filter_map { |e| Game.new(e) if e.is_a?(Hash) }
+  rescue => e
+    warn "Catalog fetch error: #{e}"
+    []
+  end
+
+  def play_url(path)
+    "#{GAMES_URL}#{path}"
+  end
+end