Implement whitelist-gated buy function for early access keys

[Chucks1093]

Summary

Extend the creator key contract with an optional whitelist gate on buy transactions, allowing creators to restrict purchases to a pre-approved set of wallet addresses during an early access window.

Scope

• set_whitelist(key_id, wallets[]) — creator-only, batch add wallets
• remove_from_whitelist(key_id, wallet) — creator-only
• is_whitelisted(key_id, wallet) — view check
• buy function checks whitelist when gate is active
• disable_whitelist(key_id) — permanently opens buys to all

Acceptance Criteria

• Buy blocked for non-whitelisted wallets when gate is active
• Whitelisted wallets buy successfully while gate is active
• disable_whitelist opens buys correctly and cannot be re-enabled
• Batch set_whitelist handles up to 100 wallets per call
• WhitelistUpdated event emitted on every add and remove

ETA

24 hours

[toniasteve15-ui]

@toniasteve15-ui has applied to work on this issue as part of the Stellar Wave Program's 9th wave.

Hello @maintainer, I’d like to work on this issue. I have experience handling similar tasks and can start immediately. And I will deliver at the shortest possible time.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @toniasteve15-ui to this issue.

[Wiseman52]

@Wiseman52 has applied to work on this issue as part of the Stellar Wave Program's 9th wave.

Hi, kindly assign task. I’ve carefully reviewed the requirements and understand what is needed to resolve the issue.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Wiseman52 to this issue.

[Lurdings]

@Lurdings has applied to work on this issue as part of the Stellar Wave Program's 9th wave.

Hi Maintainer, I’m interested in this issue. I have experience with similar work and can start right away.

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

[LayanGift]

@LayanGift has applied to work on this issue as part of the Stellar Wave Program's 9th wave.

Hi, I’m interested in taking ownership of this task. I’m confident in my ability to address the issue and submit a quality pull request once completed.

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

[mysterio123865]

@mysterio123865 has applied to work on this issue as part of the Stellar Wave Program's 9th wave.

Hello I will like resolve this
will implement everything as stated and submit a well tested result without cl failure

ℹ️ Repo Maintainers: To accept this application, review their application or assign @mysterio123865 to this issue.

[drips-wave]

Congratulations, @toniasteve15-ui! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on September 30, 2026.

🧑‍💻 @toniasteve15-ui: 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 🌊