Competition rows (events.services.competitions' per-club data-source gate) could previously only be managed through the Django admin. Adds a card alongside Flags/Switches with create/edit/delete, mirroring the Flags card's own modal pattern -- no cascading effects to weigh on delete since Event.competition matches by name, not a foreign key. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01ECGMEwrc2k4D8VQuwjstj9