Add structured log for creator registration with duplicate wallet address

[Chucks1093]

Summary
When a creator registration is attempted with a wallet address that is already registered, the error is returned to the client but not logged. A warn-level structured log at the duplicate detection point helps identify whether duplicates are accidental retries or deliberate attempts.

Scope

• identify where duplicate wallet address detection occurs during creator registration
• add a warn-level structured log with the duplicate address and request ID
• ensure the address is not logged in plain text if masking is required by policy

Acceptance Criteria

• a duplicate wallet address registration emits a warn-level log
• the log includes sufficient context to identify the request
• the client error response is unchanged

Contributor coordination: if you pick this up, reach out in Telegram for updates or clarification: https://t.me/accesslayerorg

[ayinde38]

@ayinde38 has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

will love to work on this

ℹ️ Repo Maintainers: To accept this application, review their application or assign @ayinde38 to this issue.

[dot-enny]

@dot-enny has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

Hi, i think i can handle this.

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

[drips-wave]

Congratulations, @ayinde38! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 2, 2026.

🧑‍💻 @ayinde38: 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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