feat: add quick demo login, fix archived knowledge filter and workflow completion state

perf: optimize login transition and dashboard loading performance

docs: comprehensive README, fix delete button (204), retry on any status

fix: auto-redirect to login on 401 (expired token)

feat: serve frontend from FastAPI in Docker, auto same-origin in prod

restore: revert deployment hacks, back to clean local-first state with Docker for HF Pro

feat: HF Pro Docker deployment - full stack in one container

Initial project foundation