Set up automated contract fuzz testing pipeline

[Smartdevs17]

Description

Manual testing misses edge cases. Set up automated fuzz testing for smart contracts in CI.

Acceptance Criteria

• cargo-fuzz targets for subscription functions
• CI fuzz run with minimum duration (30min)
• Corpus management with seed generation
• Crash triage and regression test generation
• Coverage-guided fuzzing
• Documentation for adding new fuzz targets

Technical Scope

• contracts/tests/fuzz.rs
• .github/workflows/fuzz-test.yml
• contracts/subscription/FUZZING.md
• Edge: fuzzing timeout handling, CI resource allocation, non-deterministic crashes

[activatedkc]

@activatedkc has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

Hello,

I am a smart contract and full-stack developer interested in contributing to this issue. I am experienced with hands-on experience in Rust, Soroban, Go, Cairo, Solidity, and TypeScript.

I am passionate about building secure and scalable blockchain solutions, with a strong focus on writing clean, maintainable code. Based on the scope of this issue, I am confident I can deliver a complete solution within 24 hours of assignment.

I would appreciate the opportunity to contribute and help move this forward.

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

[drips-wave]

Congratulations, @activatedkc! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 2, 2026.

🧑‍💻 @activatedkc: 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 🌊