Enforce strict 1-page A4 layout, 11pt default body typography, zero-hallucination grounding, and clean PDF printing

fix: adjust print layout reset to prevent height cutoff

feat: push cleaned code and correct encoding for print styles

fix: resolve print layout truncation by hiding parent heights

fix: remove browser print header and footer

fix: use current window for printing to bypass popup blockers

feat: complete next.js frontend and fastapi backend