[Enhancement] No claim submission fraud detection

[nonsobethel0-dev]

No fraud detection for claim submissions. Duplicate or fraudulent claims not caught.

Files: contracts/claims-processor/src/lib.rs

Fix: Add fraud detection rules and scoring.

[Bobai100]

@Bobai100 has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

Hi Maintainer,
I’d really appreciate the opportunity to work on this issue. Having reviewed the acceptance criteria, I’m confident that I can submit a PR after being assigned.
Please kindly assign this issue to me.
Thank you!

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Bobai100 to this issue.