wiki: add Head First Software Architecture (teaching-oriented, mapped to this project)
docs: 初始化 wiki — 簡介、維護、路線圖、計畫與技術債 Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01JP4evifDq8SDnZWnAq6psU