Add invoice creator reputation aggregator

[Kingsman-99]

Label: complexity: high
Points: 200

Description

Beyond the on-chain per-payer reputation counter (contract issue #24), the SDK should expose a creator-side reputation score combining completion rate, average funding time, and dispute rate, for display in trust indicators.

Technical Context

New src/creatorReputation.ts. Aggregates across Invoice[] for a given creator: completed vs. total, average time-to-fund (reuse Issue 17's SLA tracker), and dispute count (if src/compliance.ts exposes dispute data).

Acceptance Criteria

• computeCreatorReputation(creator, invoices) returns a 0-100 score plus the component breakdown
• Score formula is documented and unit-testable (weights as named constants)
• Handles creators with zero invoices (returns a clearly-marked "insufficient data" result, not 0)
• Tests: high-performing creator scores high; insufficient-data case handled distinctly

---

[yugomania]

@yugomania has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hello, I’ve gone through the requirements and I’m confident I can implement a proper solution that matches the acceptance criteria. Kindly assign this issue to me.

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

[cybermax4200]

@cybermax4200 has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Please assign me I can work on this

ℹ️ Repo Maintainers: To accept this application, review their application or assign @cybermax4200 to this issue.

[drips-wave]

Congratulations, @cybermax4200! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 30, 2026.

🧑‍💻 @cybermax4200: Please resolve the issue such that the repo's maintainers have enough time to review your contribution before the due date. You'll earn Points for completing the issue on-time, which will make you eligible for a share of the Stellar Wave Program's reward pool.

Warning

When opening a PR, please link it to this issue to ensure it gets tracked accurately. Points are awarded when this issue is marked as completed by the maintainer.

🤠 Repo maintainers: Please keep an eye on the contributor's progress and review their work before the due date. You can manage this issue, including adjusting its complexity and points, here.

🌊 Happy Wave 🌊

[grantfox-oss]

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

@cybermax4200's PR #259 was approved and merged by @Kingsman-99.

🏆 @cybermax4200: You earned 35 FoxPoints for this contribution! Your current tier: Explorer (296 total points). Track your full progress on GrantFox.

👏 Great work, @cybermax4200! Keep contributing to Stellar-split.

[drips-wave]

This issue has been completed by @cybermax4200 as part of the Stellar Wave Program's 6th Wave 🥳

😎 @cybermax4200: You earned 200 Points for completing this issue! After the current Wave ends, you'll be eligible for a percentage of the Wave's reward pool based on the percentage of total points you've earned. Learn more here. You can also Leave a review to share your experience working on this issue.

🧑‍💻 Repo maintainers: How'd the contributor do? Leave a review to share your experience working with them.