Add structured AI courseware APIs

debug: 添加静态文件路径调试日志，排查空白页面问题

feat(courseware): AI Teacher Assistant Agent 模块化

Add POST /api/quiz/generate for external sites, docs section 6

Add teacher agent, docs, and project updates; ClareVoiceV1 remains untracked (nested repo)

Add Clare product UI: run_web.sh, README, exclude hf_space from push