Delete vault

curl --request DELETE \
  --url https://api.case.dev/vault/{id} \
  --header 'Authorization: Bearer <token>'

{
  "success": true,
  "status": "deleted",
  "deletedVault": {
    "id": "vault_abc123",
    "name": "Contract Repository",
    "objectsDeleted": 150,
    "vectorsDeleted": 4200,
    "bytesFreed": 2847362048
  }
}