feat(cli): connect setup to remote platforms

docs/cli/configuration.mdx

@@ -13,6 +13,8 @@ The quickest way to connect to an existing deployment is:
 nemo auth login --base-url https://nmp.example.com
 ```
 
+During interactive onboarding, `nemo setup` also offers to connect to a remote deployment when the currently configured platform is unreachable. It verifies and saves the new URL in the active context, then runs the same authentication flow.
+
 To configure a named context:
 
 ```bash

docs/cli/reference.mdx

@@ -42,12 +42,22 @@ nemo [GLOBAL OPTIONS] COMMAND [ARGS]...
 
 ### nemo setup
 
-Set up NeMo Platform: start services, configure a provider, install skills.
+Set up NeMo Platform: connect or start services, configure a provider, install skills.
 
-Walks through starting local services, selecting a provider, entering
-credentials, registering the provider with the platform, picking a
-default model, installing coding agent skills, and optionally deploying
-a demo agent.
+Uses an already-running platform, starts local services, or connects the
+CLI to an existing remote deployment. Then selects and registers an
+inference provider, picks a default model, installs coding agent skills,
+and optionally deploys a demo agent.
+
+The active config context remembers the Platform URL. When a remote
+deployment is already reachable, setup asks whether to continue with it,
+start local services instead, or connect to a different remote URL.
+
+To override the URL for one run only:
+  nemo --base-url http://localhost:8080 setup
+
+To persist a different URL:
+  nemo config set --base-url http://localhost:8080
 
 Requires an interactive terminal (TTY). In non-interactive contexts
 (CI, piped input), pass --auto to use environment variables instead.
@@ -64,8 +74,10 @@ nemo setup
 nemo setup --auto
 nemo setup --auto --start-services --install-skills --deploy-agent
 nemo setup --auto --start-services --ready-timeout 360
+NMP_BASE_URL=https://nmp.example.com NMP_ACCESS_TOKEN=... nemo setup --auto --no-start-services
 nemo setup --workspace my-workspace
 nemo setup --no-install-skills --no-deploy-agent
+nemo --base-url http://localhost:8080 setup
 ```
 
 **Usage:**

docs/get-started/setup.mdx

@@ -74,7 +74,7 @@ nemo setup
 
 The wizard walks through each stage:
 
-1. **Start services** — launches the platform locally
+1. **Connect to the platform** — uses a running platform, starts services locally, or connects to a remote instance
 2. **Choose a provider** — select your model provider and enter your API key
 3. **Register the provider** — connects the provider to the platform
 4. **Discover models** — finds available models from your provider
@@ -84,6 +84,21 @@ The wizard walks through each stage:
 
 Each stage is idempotent — you can re-run `nemo setup` at any time to add more providers or update your configuration.
 
+### Connect to an existing deployment
+
+When the configured platform is not reachable, the setup wizard offers three choices:
+
+```text
+Platform not reachable at http://localhost:8080. Start local services?
+  1. Yes, start services now
+  2. No, I want to connect to a remote Platform instance
+  3. No, I'll start them myself
+```
+
+Choose the remote option and enter the deployment's base URL. Setup verifies the URL, saves it to the active CLI context, and starts the existing OIDC login flow when the deployment has authentication enabled. It then continues with provider, model, skills, and demo-agent setup.
+
+This connects the local CLI to an existing deployment; it does not install the platform on a remote host.
+
 ### Auth and OIDC source installs
 
 `nemo setup` and `nemo services run` do not create authorization role bindings by themselves. If you enable auth in source config with `auth.enabled: true` and set `auth.admin_email`, run the platform seed task so the bootstrap IAM bindings exist.
@@ -183,6 +198,12 @@ nemo setup --auto --start-services --install-skills --deploy-agent
 export OPENAI_API_KEY=sk-...
 nemo setup --auto
 
+# Connect to an authenticated remote platform without prompts
+export NMP_BASE_URL=https://nmp.example.com
+export NMP_ACCESS_TOKEN=...
+export OPENAI_API_KEY=sk-...
+nemo setup --auto --no-start-services
+
 # Skip skills and agent
 nemo setup --no-install-skills --no-deploy-agent
 ```