Add buy action helper text block

[Chucks1093]

Summary

Add a small helper text block near the buy action to explain the next transaction step.

Acceptance Criteria

• helper text appears near the buy action area
• copy is concise and easy to scan
• component supports disabled and loading states gracefully

Contributor coordination: https://t.me/accesslayerorg

[Luluameh]

@Luluameh has applied to work on this issue as part of the Stellar Wave Program's 3rd wave.

Hello
I would love to work on this
kindly assign me

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

[drips-wave]

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

🧑‍💻 @Luluameh: 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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🌊 Happy Wave 🌊

[drips-wave]

This issue has been completed by @Luluameh as part of the Stellar Wave Program's 3rd Wave 🥳

😎 @Luluameh: 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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