cv-c3c: add --image flag to deployment restart command

Allows callers to override container images during restart, e.g.:
  laconic-so deployment restart --image backend=ghcr.io/org/app:sha123

The override is applied to the k8s Deployment spec before
create-or-patch. Docker/compose deployers accept the parameter
but ignore it.

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

stack_orchestrator/deploy/deploy.py

@@ -137,7 +137,11 @@ def create_deploy_context(
 
 
 def up_operation(
-    ctx, services_list, stay_attached=False, skip_cluster_management=False
+    ctx,
+    services_list,
+    stay_attached=False,
+    skip_cluster_management=False,
+    image_overrides=None,
 ):
     global_context = ctx.parent.parent.obj
     deploy_context = ctx.obj
@@ -156,6 +160,7 @@ def up_operation(
         detach=not stay_attached,
         skip_cluster_management=skip_cluster_management,
         services=services_list,
+        image_overrides=image_overrides,
     )
     for post_start_command in cluster_context.post_start_commands:
         _run_command(global_context, cluster_context.cluster, post_start_command)