Add timelock for contract upgrade()

[Abidoyesimze]

Problem

upgrade() is instant. A compromised owner key can swap WASM immediately with no recovery window.

Scope

• upgrade, new storage for pending upgrade hash + activation ledger

Acceptance criteria

• Two-step or timelocked upgrade with cancel path.
• Tests for schedule, execute, and cancel flows.

[rahimatonize]

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

Hi maintainer, I would love to work on this issue please, assign it to me

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

[Gutopro]

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

Can this be assigned to me

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[Anichris-koded]

Hi, my name is Koded, and I am an experienced blockchain developer specializing in smart contract security, governance, and protocol reliability. I have a strong track record of implementing safeguards such as timelock mechanisms to enhance transparency and reduce risks associated with contract upgrades. My approach focuses on designing secure, well-tested upgrade workflows that provide stakeholders with adequate notice before changes take effect, strengthening trust, improving governance processes, and ensuring the long-term stability of decentralized applications.

[Joycejay17]

@Joycejay17 has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hey there maintainer, I am a software engineer with a lot of blockchain experience. I have read through the Issue description and with my experience in stellar projects can get this delivered ASAP.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Joycejay17 to this issue.

[Caneryy]

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

Hello, please can I work on this issue?

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

[drips-wave]

Congratulations, @Joycejay17! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 30, 2026.

🧑‍💻 @Joycejay17: 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

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[grantfox-oss]

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

@Joycejay17's PR #357 was approved and merged by @Abidoyesimze.

🏆 @Joycejay17: You earned 35 FoxPoints for this contribution! Your current tier: Explorer (366 total points). Track your full progress on GrantFox.

👏 Great work, @Joycejay17! Keep contributing to Neurowealth.