[P2] Blockchain: Implement multi-sig approval for high-value subscription renewals

[Calebux]

Description

Add multi-signature approval workflow for subscription renewals exceeding a configurable threshold, requiring team admin co-sign via Stellar multi-sig.

Acceptance Criteria

• Configurable threshold per team (default: $100 USD equivalent)
• Stellar multi-sig transaction building
• Notification to required signers
• Time-limited signing window (24h default)
• Auto-cancel if signing window expires
• Audit log of approval/rejection decisions

[Jenola344]

@Jenola344 has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hi maintainer, I will love to work on this project

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Jenola344 to this issue.

[No-bodyq]

@No-bodyq has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hello
i will love to work on this issue
kindly assign

ℹ️ Repo Maintainers: To accept this application, review their application or assign @No-bodyq to this issue.

[drips-wave]

Congratulations, @Jenola344! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 30, 2026.

🧑‍💻 @Jenola344: 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 🌊

[drips-wave]

This issue has been marked as completed by a Drips Wave moderator for @Jenola344 as part of the Stellar Wave Program's 6th Wave 🥳

Moderator's reason: [Auto-assessed] The PR provides a comprehensive implementation of the multi-sig approval workflow as requested in the issue, covering thresholds, signing windows, expiry logic, and audit logging. The code is substantial and directly addresses all acceptance criteria with no maintainer objections.

😎 @Jenola344: 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.

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

ℹ️ Note: This issue was marked complete via moderation. Points were issued even though the GitHub issue remains open.