node list and module list answer --json, and the nodes and modules verbs use it (hq ADR 0195)

The console's discovery reads the machines and the modules; parsing a printed column breaks when it
is reworded. Both now answer JSON on --json, as status and seats do, and the seat verbs ask for it.

cmd/mesh-controller/seatverbs_test.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"fmt"
 	"strings"
 	"testing"
 
@@ -249,3 +250,17 @@ func TestARowAheadOfThisBuildIsServedAnyway(t *testing.T) {
 		}
 	}
 }
+
+// novox/hq ADR 0195: the console's discovery reads the machines and the modules; they answer as JSON,
+// as status and seats do, so nothing parses a printed column.
+func TestTheNodesAndModulesVerbsAnswerAsJSON(t *testing.T) {
+	for verb, want := range map[string]string{"nodes": "[node list --json]", "modules": "[module list --json]"} {
+		argv, err := argvFor(verb, map[string]any{})
+		if err != nil {
+			t.Fatal(err)
+		}
+		if fmt.Sprint(argv) != want {
+			t.Errorf("%s runs %v, want %s", verb, argv, want)
+		}
+	}
+}