Add helper for validating Stellar address format before persisting to database

[Chucks1093]

Summary

Stellar addresses submitted via API are stored in the database without format validation. An invalid address that passes into storage will cause downstream failures that are harder to diagnose. A validation helper should check the format at the API boundary before any write.

Scope

• Add isValidStellarAddress(address: string): boolean helper
• Valid addresses start with G, are exactly 56 characters, and contain only base32 alphanumeric characters
• Apply the helper in all endpoints that accept a wallet or recipient address in the request body
• Add unit tests: valid address returns true, wrong starting character, wrong length, invalid characters each return false

Acceptance Criteria

• Valid Stellar address returns true
• Wrong starting character returns false
• Wrong length returns false
• Invalid characters return false
• Helper applied at all address-accepting endpoints

ETA: 12 hours

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Coordinate on Telegram

[0xNinx]

@0xNinx has applied to work on this issue as part of the Stellar Wave Program's 7th wave.

gm gm Maintainer, I have reviewed the issue description and understand the requirements. Can you assign me this please? ETA: 8hours. Thank you

ℹ️ Repo Maintainers: To accept this application, review their application or assign @0xNinx to this issue.

[abayomicornelius]

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

Please let me work on this

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

[drips-wave]

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

🧑‍💻 @abayomicornelius: 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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