docs: pin OpenSandbox how-to slug to open-sandbox

docs/customizer/grpo-training.mdx

@@ -454,7 +454,7 @@ GRPO fails at submit, before any GPU is claimed, unless the platform operator ha
 
 If a submit fails on either of the first two, that is a platform configuration gap, not a problem with your package. Neither is settable per job.
 
-Installing OpenSandbox is a separate operator task: [OpenSandbox](/documentation/kubernetes-deployment/setup/helm/opensandbox), or [OpenSandbox with Kata](/documentation/kubernetes-deployment/setup/helm/opensandbox-kata) for the Kata runtime.
+Installing OpenSandbox is a separate operator task: [OpenSandbox](/documentation/kubernetes-deployment/setup/helm/open-sandbox), or [OpenSandbox with Kata](/documentation/kubernetes-deployment/setup/helm/opensandbox-kata) for the Kata runtime.
 
 ## Next Steps
 

docs/customizer/tutorials/grpo-environment-packages.mdx

@@ -24,7 +24,7 @@ Do not put `.jsonl` in the environment package. If a Gym config lists `datasets[
 Before packaging an environment, ensure you have:
 
 1. **A NeMo Platform configured with `platform.runtime: kubernetes`** — GRPO provisions a Ray cluster and has no local Docker fallback
-2. **Sandboxed Gym enabled on the cluster** by your platform operator (`sandbox_cluster_capable` and a job-storage PVC claim). Refer to [Cluster prerequisites](/documentation/customizer-reference/grpo-and-reward-environments#cluster-prerequisites); installing OpenSandbox is covered in [OpenSandbox](/documentation/kubernetes-deployment/setup/helm/opensandbox)
+2. **Sandboxed Gym enabled on the cluster** by your platform operator (`sandbox_cluster_capable` and a job-storage PVC claim). Refer to [Cluster prerequisites](/documentation/customizer-reference/grpo-and-reward-environments#cluster-prerequisites); installing OpenSandbox is covered in [OpenSandbox](/documentation/kubernetes-deployment/setup/helm/open-sandbox)
 3. **The `nemo` CLI on your `PATH`**, or a source checkout where `uv run --package nmp-rl` resolves
 4. **The training image tag** your cluster runs — vendoring a wheel closure requires the `nemo-gym`, `ray`, and `openai` versions it reports
 5. **A machine with internet access** for the packaging step. Training clusters consume uploaded FileSets only. For details on which environment type require internet access too, see details below.
@@ -430,7 +430,7 @@ nemo files upload ./weather-env/ weather-env --workspace default
 nemo files list weather-env --workspace default
 ```
 
-Job JSON: [GRPO and Reward Environments](/documentation/customizer-reference/grpo-and-reward-environments#submit-the-job). Sandboxed Gym is configured on the platform (`NMP_RL_SANDBOXED_GYM_DEFAULT`), not in the job payload. Cluster setup: [OpenSandbox](/documentation/kubernetes-deployment/setup/helm/opensandbox).
+Job JSON: [GRPO and Reward Environments](/documentation/customizer-reference/grpo-and-reward-environments#submit-the-job). Sandboxed Gym is configured on the platform (`NMP_RL_SANDBOXED_GYM_DEFAULT`), not in the job payload. Cluster setup: [OpenSandbox](/documentation/kubernetes-deployment/setup/helm/open-sandbox).
 
 ## Next Steps
 

docs/fern/docs.yml

@@ -36,6 +36,15 @@ redirects:
   # Sphinx page URLs (foo.html); must follow all :path*/index.html rules above
   - source: "/:path*.html"
     destination: "/:path*"
+  # NV 6722631: OpenSandbox how-to live slug is open-sandbox.
+  - source: "/documentation/self-managed-deployment/setup/helm/opensandbox"
+    destination: "/documentation/kubernetes-deployment/setup/helm/open-sandbox"
+  - source: "/latest/documentation/self-managed-deployment/setup/helm/opensandbox"
+    destination: "/latest/documentation/kubernetes-deployment/setup/helm/open-sandbox"
+  - source: "/documentation/kubernetes-deployment/setup/helm/opensandbox"
+    destination: "/documentation/kubernetes-deployment/setup/helm/open-sandbox"
+  - source: "/latest/documentation/kubernetes-deployment/setup/helm/opensandbox"
+    destination: "/latest/documentation/kubernetes-deployment/setup/helm/open-sandbox"
   # NV 6722623: published hrefs still use the old self-managed-deployment nav slug.
   - source: "/documentation/self-managed-deployment/helm"
     destination: "/documentation/kubernetes-deployment/setup/helm"

docs/fern/versions/latest.yml

@@ -390,6 +390,7 @@ navigation:
                   - page: Volcano
                     path: ../../set-up/helm/volcano.mdx
                   - page: OpenSandbox
+                    slug: open-sandbox
                     path: ../../set-up/helm/opensandbox.mdx
                   - page: OpenSandbox with Kata
                     slug: opensandbox-kata

docs/set-up/helm/index.mdx

@@ -76,7 +76,7 @@ Install the Volcano scheduler for multi-node jobs. The chart does not install Vo
 <small><span class="md-tag">cluster-admin</span></small>
 
 </Card>
-<Card title="OpenSandbox" href="/documentation/kubernetes-deployment/setup/helm/opensandbox">
+<Card title="OpenSandbox" href="/documentation/kubernetes-deployment/setup/helm/open-sandbox">
 
 Install OpenSandbox with the shared-kernel / default runtime path and point jobs at the in-cluster server.
 

docs/set-up/helm/install.mdx

@@ -198,7 +198,7 @@ The chart does not install these. Install them before the workloads that need th
 
 - [Volcano](/documentation/kubernetes-deployment/setup/helm/volcano), required for multi-node scheduling
 - [Kyverno](/documentation/kubernetes-deployment/setup/helm/multinode-networking), required for multi-node NCCL device injection
-- [OpenSandbox](/documentation/kubernetes-deployment/setup/helm/opensandbox) required for sandboxed GRPO; [Kata](/documentation/kubernetes-deployment/setup/helm/opensandbox-kata) for VM-isolated sandboxes
+- [OpenSandbox](/documentation/kubernetes-deployment/setup/helm/open-sandbox) required for sandboxed GRPO; [Kata](/documentation/kubernetes-deployment/setup/helm/opensandbox-kata) for VM-isolated sandboxes
 
 ## Install the chart
 

docs/set-up/helm/opensandbox-kata.mdx

@@ -7,7 +7,7 @@ description: "Install Kata Containers and an OpenSandbox server that pins sandbo
 ---
 <a id="install-opensandbox-kata"></a>
 
-Use this path when **sandboxed GRPO / NeMo Gym** sandbox pods must be isolated from the host kernel. We document **Kata QEMU** (`RuntimeClass/kata-qemu`) because it runs each sandbox in a QEMU VM with its own guest kernel. Other kernel-isolated runtimes (for example Kata Firecracker, or a different hardware-isolated RuntimeClass) may work the same way, but they have **not been tested** with NeMo Platform. **Kata is optional**; most installs only need the [shared-kernel OpenSandbox](/documentation/kubernetes-deployment/setup/helm/opensandbox) path. This does **not** sandbox the rest of the platform (API, DPO, SFT, inference).
+Use this path when **sandboxed GRPO / NeMo Gym** sandbox pods must be isolated from the host kernel. We document **Kata QEMU** (`RuntimeClass/kata-qemu`) because it runs each sandbox in a QEMU VM with its own guest kernel. Other kernel-isolated runtimes (for example Kata Firecracker, or a different hardware-isolated RuntimeClass) may work the same way, but they have **not been tested** with NeMo Platform. **Kata is optional**; most installs only need the [shared-kernel OpenSandbox](/documentation/kubernetes-deployment/setup/helm/open-sandbox) path. This does **not** sandbox the rest of the platform (API, DPO, SFT, inference).
 
 Complete the OpenSandbox namespace, Secret, and platform-values steps first; this page only adds virtualization prerequisites and the Kata server overlay.