Fix mcp ps showing registry version instead of runtime, error on unknown component

mcp ps now uses the actual container image and version from the runtime
instead of the registry, which could be stale after a failed deploy.

Deploy now returns an error when the component filter matches nothing
instead of silently succeeding with zero results.

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

internal/agent/deploy.go

@@ -34,6 +34,9 @@ func (a *Agent) Deploy(ctx context.Context, req *mcpv1.DeployRequest) (*mcpv1.De
 				filtered = append(filtered, cs)
 			}
 		}
+		if len(filtered) == 0 {
+			return nil, fmt.Errorf("component %q not found in service %q", target, serviceName)
+		}
 		components = filtered
 	}