Delete merge-check.sh; tests that launch bundles skip with their reason (issue 1295, S2; ADR 0529)

The checker runs node-tools' Go level and its npm test; what the script said
was NOT TESTED HERE is a skip naming the missing node or @novox/mesh-sdk.

node-tools/internal/meshtest/bundles.go

@@ -0,0 +1,38 @@
+package meshtest
+
+import (
+	"os"
+	"os/exec"
+	"path/filepath"
+	"runtime"
+	"testing"
+)
+
+// bundlesWhy returns the reason bundles cannot be launched from a checkout rooted at root, or "" when they can: the
+// TypeScript and Python bundles the runtime and the console launch need node and the package
+// @novox/mesh-sdk, which comes from the package registry and is installed beside node-tools/package.json
+// (novox/hq ADR 0529 clause 1: what merge-check.sh said "NOT TESTED HERE" about is a skip with its reason).
+func bundlesWhy(root string, haveNode bool) string {
+	if !haveNode {
+		return "node is not installed"
+	}
+	if _, err := os.Stat(filepath.Join(root, "node_modules", "@novox", "mesh-sdk")); err != nil {
+		return "@novox/mesh-sdk is not installed in " + filepath.Join(root, "node_modules")
+	}
+	return ""
+}
+
+// NeedBundles skips the test, saying why, where the bundles it launches cannot run here.
+func NeedBundles(t *testing.T) {
+	t.Helper()
+	_, err := exec.LookPath("node")
+	if why := bundlesWhy(moduleRoot(), err == nil); why != "" {
+		t.Skip("NOT TESTED HERE: this test launches bundles, and " + why)
+	}
+}
+
+// moduleRoot is node-tools/, where package.json and node_modules are.
+func moduleRoot() string {
+	_, here, _, _ := runtime.Caller(0)
+	return filepath.Join(filepath.Dir(here), "..", "..")
+}

node-tools/internal/meshtest/meshtest_test.go

@@ -73,3 +73,20 @@ func TestEachTestHasABusOfItsOwn(t *testing.T) {
 		}
 	})
 }
+
+// What merge-check.sh said was "NOT TESTED HERE" is a skip with its reason: no node, or no package, each says so.
+func TestBundlesCannotBeLaunchedWithoutNodeOrTheSDKAndTheSkipSaysWhy(t *testing.T) {
+	root := t.TempDir()
+	if why := bundlesWhy(root, false); !strings.Contains(why, "node is not installed") {
+		t.Errorf("no node said %q", why)
+	}
+	if why := bundlesWhy(root, true); !strings.Contains(why, "@novox/mesh-sdk") {
+		t.Errorf("no package said %q", why)
+	}
+	if err := os.MkdirAll(filepath.Join(root, "node_modules", "@novox", "mesh-sdk"), 0o755); err != nil {
+		t.Fatal(err)
+	}
+	if why := bundlesWhy(root, true); why != "" {
+		t.Errorf("node and the package present said %q", why)
+	}
+}