fix: create imagePullSecret in deployment namespace, not default

create_registry_secret() hardcoded namespace="default" but deployments
now run in dedicated laconic-* namespaces. The secret was invisible
to pods in the deployment namespace, causing 401 on GHCR pulls.

Accept namespace as parameter, passed from deploy_k8s.py which knows
the correct namespace.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

stack_orchestrator/deploy/k8s/deploy_k8s.py

@@ -541,7 +541,9 @@ class K8sDeployer(Deployer):
         # Create registry secret if configured
         from stack_orchestrator.deploy.deployment_create import create_registry_secret
 
-        create_registry_secret(self.cluster_info.spec, self.cluster_info.app_name)
+        create_registry_secret(
+            self.cluster_info.spec, self.cluster_info.app_name, self.k8s_namespace
+        )
 
         self._create_volume_data()
         self._create_deployment()