Set Safe Currency

This endpoint sets the appropriate token symbol (currency) for a user's Safe account based on their country. It should be called after deploying a Safe account using the /api/v1/account endpoint.

The system assigns currencies based on user's country:

• UK users (GB): GBPe
• Brazil users (BR): USDCe
• Users from other countries: EURe (default)

Prerequisite: User must have completed and passed KYC verification.