Upgradability security review

[Levi-Ojukwu]

Description:

The contract upgrade mechanism needs a security review to ensure:

1. Only authorized upgrades can be performed
2. Storage remains compatible across versions
3. Upgrades cannot be used to bypass security controls
4. Upgrade events are properly emitted

Why it matters: Insecure upgrade mechanisms can be exploited to take over the contract.

Acceptance Criteria:

• Analyze upgrade authorization flow
• Verify storage compatibility across versions
• Add upgrade tests
• Document in docs/upgrade-guide.md

Relevant Files: contracts/invoice_liquidity/src/lib.rs:492-507, docs/upgrade-guide.md

---

[Lazaruster]

@Lazaruster has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

I'd like to work on this issue! because I am very conversant with solving problems like this!

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

[Yilkash]

@Yilkash has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

Can i work on this?

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

[drips-wave]

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

🧑‍💻 @Yilkash: 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.

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🌊 Happy Wave 🌊

[drips-wave]

This issue has been completed by @Yilkash as part of the Stellar Wave Program's 7th Wave 🥳

😎 @Yilkash: 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.

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