docs: fix remaining hardcoded headlamp namespace to <your-namespace> placeholder

Prior commit was inconsistent — some files used <your-namespace> while
DEPLOYMENT.md, TROUBLESHOOTING.md and several troubleshooting/user-guide
docs still hardcoded headlamp as the namespace.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

docs/DEPLOYMENT.md

@@ -33,7 +33,7 @@ kubectl -n polaris get svc polaris-dashboard
 kubectl get --raw /api/v1/namespaces/polaris/services/polaris-dashboard:80/proxy/results.json | jq .PolarisOutputVersion
 
 # Verify Headlamp is deployed
-kubectl -n headlamp get pods -l app.kubernetes.io/name=headlamp
+kubectl -n <your-namespace> get pods -l app.kubernetes.io/name=headlamp
 ```
 
 ## Installation Methods
@@ -59,7 +59,7 @@ kubectl -n headlamp get pods -l app.kubernetes.io/name=headlamp
 
    ```bash
    helm upgrade --install headlamp headlamp/headlamp \
-     --namespace headlamp \
+     --namespace <your-namespace> \
      --values headlamp-values.yaml
    ```