docs(asl): Add fulltext screening frontend development plan and technical debt
- Create comprehensive frontend development plan (05-全文复筛前端开发计划.md)
- 4 core pages design (Settings, Progress, Workbench, Results)
- 10 feature components and 3 reused components
- Detailed UI/UX specifications with wireframes
- 2.5-day development schedule (Day 6-8)
- Technical implementation guide (PDF upload, progress polling, PDF preview)
- Testing plan (functional, performance, compatibility)
- Update technical debt list (v1.1 -> v1.2)
- Add 10 frontend-related technical debts (debt 11-20)
- PDF annotation feature (medium priority)
- Literature note-taking (medium priority)
- Knowledge base integration (low priority)
- Auto-fetch PDF by PMID/DOI (low priority)
- Highlight AI-cited text in PDF (medium priority)
- WebSocket real-time push (low priority)
- Virtual scrolling optimization (low priority)
- Batch operations (low priority)
- Offline PDF preview (low priority)
- Mobile responsive design (lowest priority)