ConfigErrorCode
Why setup failed.
For example: missing_secret is an unset secret, duplicate_name two tools or agents with one name, capability_missing an option the sandbox or model can't support.
type ConfigErrorCode = "invalid_config" | "missing_secret" | "unknown_preset" | "duplicate_name" | "capability_missing" | "mcp_unreachable" | "budget_unenforceable" | "permission_rule_invalid" | "hosted_tool_unsupported" | "egress_policy_unsupported" | "transport_fence_unsupported";