Upgrade the caller's wallet account to a full current account

Submits the caller's KRA PIN, selfie and ID photos to the wallet provider to raise the account from its capped entry tier to the full current-account tier. The upgrade completes asynchronously via a provider callback; on success the account's limits are raised. Returns 409 if the caller has no active, upgradeable current account.

curl -X POST "https://example.com/v1/user/accounts/current/upgrade" \  -H "Content-Type: application/json" \  -d '{    "kra_pin": "string",    "selfie_photo": "string"  }'

{  "code": "BAD_REQUEST",  "description": "Bad Request"}

{  "code": "UNAUTHORISED",  "description": "Unauthorised"}

{  "code": "WAITING_LIST",  "description": "User is in the waiting list"}

{  "code": "TOO_MANY_REQUESTS",  "description": "Too Many Requests"}

{  "code": "INTERNAL_SERVER_ERROR",  "description": "Internal Server Error"}