feat(cli): add --device as an alias for --gpu

Signed-off-by: Evan Lezar <elezar@nvidia.com>

Author: elezar

architecture/gateway-single-node.md

@@ -316,9 +316,9 @@ Host GPU drivers & NVIDIA Container Toolkit
                 └─ Pods: request nvidia.com/gpu in resource limits
 ```
 
-### `--gpu` flag
+### `--gpu` / `--device` flag
 
-The `--gpu` flag on `gateway start` accepts an optional value that overrides the automatic injection mode:
+The `--gpu` flag (aliased as `--device`) on `gateway start` accepts an optional value that overrides the automatic injection mode:
 
 | Invocation | Behaviour |
 |---|---|

crates/openshell-cli/src/main.rs

@@ -788,7 +788,7 @@ enum GatewayCommands {
         /// `nvidia.com/gpu` resources. Requires NVIDIA drivers and the
         /// NVIDIA Container Toolkit on the host.
         ///
-        /// An optional argument controls the injection mode:
+        /// An optional argument controls the injection mode (`--device` is an alias):
         ///
         ///   --gpu              Auto-select: CDI on Docker >= 28.2.0, legacy otherwise
         ///   --gpu=legacy       Force legacy nvidia DeviceRequest (specify once only)
@@ -797,6 +797,7 @@ enum GatewayCommands {
         /// Example CDI device names: `nvidia.com/gpu=all`, `nvidia.com/gpu=0`
         #[arg(
             long = "gpu",
+            alias = "device",
             num_args = 0..=1,
             default_missing_value = "auto",
             action = clap::ArgAction::Append,

docs/sandboxes/manage-gateways.md

@@ -168,7 +168,7 @@ $ openshell gateway info --name my-remote-cluster
 
 | Flag | Purpose |
 |---|---|
-| `--gpu` | Enable NVIDIA GPU passthrough. Requires NVIDIA drivers and the Container Toolkit on the host. Accepts an optional value: omit for auto-select (CDI on Docker >= 28.2.0, `--gpus all` otherwise), `--gpu=legacy` to force `--gpus all`, or `--gpu=<cdi-device>` to inject a specific CDI device (e.g. `nvidia.com/gpu=all`). May be repeated for multiple CDI devices. |
+| `--gpu` / `--device` | Enable NVIDIA GPU passthrough. Requires NVIDIA drivers and the Container Toolkit on the host. Accepts an optional value: omit for auto-select (CDI on Docker >= 28.2.0, `--gpus all` otherwise), `--gpu=legacy` to force `--gpus all`, or `--gpu=<cdi-device>` to inject a specific CDI device (e.g. `nvidia.com/gpu=all`). May be repeated for multiple CDI devices. |
 | `--plaintext` | Listen on HTTP instead of mTLS. Use behind a TLS-terminating reverse proxy. |
 | `--disable-gateway-auth` | Skip mTLS client certificate checks. Use when a reverse proxy cannot forward client certs. |
 | `--registry-username` | Username for registry authentication. Defaults to `__token__` when `--registry-token` is set. Only needed for private registries. Also configurable with `OPENSHELL_REGISTRY_USERNAME`. |