refactor(core): move DEFAULT_K8S_NAMESPACE into K8s driver

The constant is Kubernetes-specific (used only by KubernetesComputeConfig's
Default impl) and does not belong in openshell-core. Relocate it to the
driver crate that owns the K8s vocabulary; openshell-core retains only
truly cross-cutting defaults.

Author: TaylorMutch

crates/openshell-core/src/config.rs

@@ -42,9 +42,6 @@ pub const DEFAULT_SUPERVISOR_IMAGE: &str = "openshell/supervisor:latest";
 /// Default image pull policy for sandbox images.
 pub const DEFAULT_IMAGE_PULL_POLICY: &str = "missing";
 
-/// Default Kubernetes namespace for sandbox resources.
-pub const DEFAULT_K8S_NAMESPACE: &str = "openshell";
-
 /// CDI device identifier for requesting all NVIDIA GPUs.
 pub const CDI_GPU_DEVICE_ALL: &str = "nvidia.com/gpu=all";
 

crates/openshell-driver-kubernetes/src/config.rs

@@ -1,9 +1,12 @@
 // SPDX-FileCopyrightText: Copyright (c) 2025-2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 // SPDX-License-Identifier: Apache-2.0
 
-use openshell_core::config::{DEFAULT_K8S_NAMESPACE, DEFAULT_SUPERVISOR_IMAGE};
+use openshell_core::config::DEFAULT_SUPERVISOR_IMAGE;
 use serde::{Deserialize, Serialize};
 
+/// Default Kubernetes namespace for sandbox resources.
+pub const DEFAULT_K8S_NAMESPACE: &str = "openshell";
+
 /// How the supervisor binary is delivered into sandbox pods.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Default, Serialize, Deserialize)]
 #[serde(rename_all = "kebab-case")]