[Backend] — Test: `OracleService.getPendingMatches` excludes future and already-submitted matches

[Olowodarey]

Background

OracleService.getPendingMatches (src/oracle/oracle.service.ts) queries
matches where match_time < now AND result_submitted = false. There are no
tests verifying that:

1. Matches with match_time > now (future) are excluded.
2. Matches with result_submitted = true are excluded.
3. Only the intersection (past AND unsubmitted) is returned.

Goal

Add tests in src/oracle/oracle.service.spec.ts (create if absent).

Requirements

1. Seed four matches:
   • Past + unsubmitted → included.
   • Past + submitted → excluded.
   • Future + unsubmitted → excluded.
   • Future + submitted → excluded.
2. Assert only the first match appears in the results.
3. Assert total = 1 in the paginated response.

Acceptance criteria

• Only past + unsubmitted matches returned.
• time_since_match_started_seconds is non-negative and approximately correct.

[gloskull]

Hello, I have 4 years of experience delivering solutions for projects like this, covering backend, frontend, and smart contract development. After carefully reviewing your requirements, I have a clear understanding of the task and am confident in my ability to deliver a clean, efficient, and thoroughly tested solution on time. I prioritize code quality, maintainability, and industry best practices throughout the development process.
My PR will be submitted in under 10hours.