feat: CLI-Skeleton mit version/serve/check und Makefile

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NBHF4R9EAejDJUMdwr6C68

cmd/vpnportal/main_test.go

@@ -0,0 +1,43 @@
+package main
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+)
+
+func TestRunVersion(t *testing.T) {
+	var out, errOut bytes.Buffer
+	code := run([]string{"version"}, &out, &errOut)
+	if code != 0 {
+		t.Fatalf("exit code = %d, want 0 (stderr: %s)", code, errOut.String())
+	}
+	got := out.String()
+	for _, want := range []string{"vpnportal", "commit", "built"} {
+		if !strings.Contains(got, want) {
+			t.Errorf("output %q missing %q", got, want)
+		}
+	}
+}
+
+func TestRunUnknownCommand(t *testing.T) {
+	var out, errOut bytes.Buffer
+	if code := run([]string{"frobnicate"}, &out, &errOut); code != 2 {
+		t.Fatalf("exit code = %d, want 2", code)
+	}
+	if !strings.Contains(errOut.String(), "frobnicate") {
+		t.Errorf("stderr should name the unknown command, got %q", errOut.String())
+	}
+}
+
+func TestRunNoArgsDefaultsToServe(t *testing.T) {
+	var out, errOut bytes.Buffer
+	// serve ohne --config muss mit Fehler abbrechen, nicht mit "unknown command"
+	code := run(nil, &out, &errOut)
+	if code == 2 {
+		t.Fatalf("no args must default to serve, not unknown-command")
+	}
+	if !strings.Contains(errOut.String(), "config") {
+		t.Errorf("stderr should complain about missing config, got %q", errOut.String())
+	}
+}