Self-serve account deletion: erase PII in place and revoke credentials (GDPR Art. 17 erasure)

curl --request DELETE \
  --url https://3ngram-server-production.up.railway.app/api/v1/account \
  --header 'Content-Type: application/json' \
  --header 'X-API-Key: <api-key>' \
  --data '
{
  "confirm": true
}
'

{
  "alreadyDeleted": true,
  "deleted": true,
  "erased": {
    "apiKeysRevoked": 4503599627370495,
    "commitments": 4503599627370495,
    "emailVerificationTokensDeleted": 4503599627370495,
    "facts": 4503599627370495,
    "memories": 4503599627370495,
    "oauthCodesDeleted": 4503599627370495,
    "oauthTokensRevoked": 4503599627370495,
    "passwordResetTokensDeleted": 4503599627370495,
    "proposals": 4503599627370495,
    "sessionsDeleted": 4503599627370495
  }
}