[Backend] — Ranked event leaderboard (replaces binary "winners" model)

[Olowodarey]

Background

There is currently no points-based leaderboard. The closest things that
exist are:

• getParticipants() in `creator-events.service.

Goal

Add a GET /creator-events/:id/leaderboard endpoint backed by the new
contract view (with a DB-cached fallback populated by Issue 6's
EventFinalized handler for finalized events), replacing the unused
winners-query.dto.ts / WinnerResponse model.

Tasks

1. ContractService (src/contract/contract.service.ts): add
2. New entity src/matches/entities/creator-event-leaderboard-entry.entity.ts
3. Migration: <timestamp>-CreateCreatorEventLeaderboardEntry.ts.
4. Rewrite src/creator-events/dto/leaderboard-query.dto.ts to match the
5. New service method getLeaderboard() in creator-events.service.ts:
   • If event.is_finalized (from the cached CreatorEvent row) → read
   • Otherwise → call contractService.getEventLeaderboard(eventId) (live),
6. New endpoint in creator-events.controller.ts:

Acceptance Criteria

• GET /creator-events/:id/leaderboard?page=1&limit=20 returns a
• For a non-finalized event, the response reads live from
• For a finalized event, the response reads from
• winners-query.dto.ts and all ContractWinner/getEventWinners

[Pvsaint]

Hi, I'm Victor, a software developer, proficient in rust, nextjs, react, typescript, etc.
I'd love to contribute to this project by taking this issue if it's available, ETA 24hrs.

[grantfox-oss]

🦊 GrantFox — @Pvsaint has been assigned to this issue as part of the Official Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #956)
2. Your PR will be reviewed by the Arena1X maintainers

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[grantfox-oss]

🎉 This issue has been marked as completed on GrantFox as part of the Official Campaign campaign!

@Pvsaint's PR #987 was approved and merged by @Olowodarey.

🏆 @Pvsaint: You earned 35 FoxPoints for this contribution! Your current tier: Explorer (48 total points). Track your full progress on GrantFox.

👏 Great work, @Pvsaint! Keep contributing to Arena1X.