FastF1's get_event() couldn't resolve several grand prix names
(Qatar, Brazilian, Mexican, Barcelona), causing 500/404 errors.
Now uses Jolpica's race schedule directly — slugifies circuitName
to match against circuits.json with ASCII fallback for unicode.

Dataclass models have parent back-references (TrackLayout→Circuit→
Locality→Country) causing infinite recursion in dataclasses.asdict().
Add to_dict() methods that exclude parent refs, use them in API endpoints.

Enables deploying f1-circuits as a HAL module on ace behind Traefik,
serving track SVGs at f1-circuits.zurag.be.