Make tip submission idempotent against double taps

[RUKAYAT-CODER]

Background

Rapid taps can submit the same tip twice. Add a client-generated idempotency key.

Files to modify (2-3)

src/services/tipService.ts
src/lib/featureFlags/tipCanary.ts

Acceptance Criteria

Implemented across the listed files

Unit/integration tests added or updated and passing

No regression; follows project coding standards

[AGWAM001]

@AGWAM001 has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

I'd love to take this issue on. I'm a full-stack developer with experience across Drips Waves4-7.
My stack include rust, Soroban, Solidity, and TypeScript. I can deliver a clean, tested, and well-documented solution within 24 hours of assignment.
Jovial to start immediately

ℹ️ Repo Maintainers: To accept this application, review their application or assign @AGWAM001 to this issue.

[Blaqkenny]

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

hello Maintainer, please can i work on this issues

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

[A-one-tech]

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

Focused on building trust through consistent, meaningful contributions. I approach every issue with curiosity, attention to detail, and a commitment to delivering clean, maintainable, and well-tested solutions. Driven by impact, not just commits, I value clear communication, effective collaboration with maintainers, continuous learning, and delivering meaningful value to every project I contribute to.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @A-one-tech to this issue.

[Wetshakat]

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

Hi maintainer
I will like to work on this Issue
ETA 4hrs

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

[Muyideen-js]

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

Hi, I can fix this

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

[p4uld4vid016-code]

@p4uld4vid016-code has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

Hello maintainer, i would like to work on this issue

ℹ️ Repo Maintainers: To accept this application, review their application or assign @p4uld4vid016-code to this issue.

[OlaBanjiolowo]

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

I’d like to work on this issue because preventing duplicate tip submissions is important for both user experience and data integrity. I would implement a client-generated idempotency key within the existing tip submission flow, following the current service and feature flag patterns rather than introducing unnecessary abstractions. I’ll add or update the relevant unit/integration tests to verify that rapid repeated submissions are handled safely, while ensuring existing tip functionality and project coding standards are preserved.

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

[drips-wave]

Congratulations, @Blaqkenny! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on August 31, 2026.

🧑‍💻 @Blaqkenny: 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 Third Campaign campaign!

@Blaqkenny's PR #1251 was approved and merged by @RUKAYAT-CODER.

🏆 @Blaqkenny: You earned 35 FoxPoints for this contribution! Your current tier: Explorer (424 total points). Track your full progress on GrantFox.

👏 Great work, @Blaqkenny! Keep contributing to rinafcode.

[drips-wave]

This issue has been completed by @Blaqkenny as part of the Stellar Wave Program's 8th Wave 🥳

😎 @Blaqkenny: 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.