feat: car-help web UI with browser view, search API, and buying guide

- FastAPI backend on port 8080 with noVNC proxy for same-origin iframe
- Split-panel UI: live browser (55%) + search/guide/saved tabs (45%)
- Car buying guide: target models, pre-purchase checklist, mechanics nearby,
  negotiation tips, budget breakdown
- Scoring/ranking engine for listings (Toyota Prius = highest)
- Docker container runs Xvfb + x11vnc + noVNC + FastAPI together
- Accessible at browser.ampbox.io via cloudflared tunnel

Dockerfile

@@ -24,6 +24,6 @@ COPY . /app/
 COPY entrypoint.sh /entrypoint.sh
 RUN chmod +x /entrypoint.sh
 
-EXPOSE 6080
+EXPOSE 6080 8080
 
 ENTRYPOINT ["/entrypoint.sh"]