test: add tests for swap and token (stake/unstake) services and handlers

[cypriannwokolo2-creator]

Summary

swap/service.go + swap_handler.go (escrow on-chain flow) and token/service.go + handler have no tests.

Acceptance Criteria

• Swap offer lifecycle (create/accept/execute/cancel) tests
• Token stake/unstake happy + error paths
• Handler-level authz tests

Complexity

High.

[AdEmOnD07]

@AdEmOnD07 has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

I would like to work on this issue
I'll be fast and perfect

ℹ️ Repo Maintainers: To accept this application, review their application or assign @AdEmOnD07 to this issue.

[achiever2110]

@achiever2110 has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

please assign to me

ℹ️ Repo Maintainers: To accept this application, review their application or assign @achiever2110 to this issue.

[redman7712]

@redman7712 has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

Hi Maintainer! I'm a senior developer with experience building high-quality, production-ready software. I'd love to take on this issue and deliver a clean, well-tested solution that aligns with the project's standards. Please assign it to me—I'm ready to get started and contribute effectively.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @redman7712 to this issue.

[drips-wave]

Congratulations, @achiever2110! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on August 31, 2026.

🧑‍💻 @achiever2110: 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 🌊