fix(utils): now it can be successfully restarted when deployed as systemd service

- Add `getSystemdServiceName` function to get systemd service name.
- When detected as systemd sevice, use `systemctl restart` to restart the program then exit.

sys/core.go

@@ -671,3 +671,21 @@ func RestartInitDService(instanceName string) error {
 	}
 	return nil
 }
+
+func GetSystemdServiceName() (string, error) {
+	data, err := os.ReadFile("/proc/self/cgroup")
+	if err == nil {
+		for _, line := range strings.Split(string(data), "\n") {
+			if !strings.Contains(line, ".service") {
+				continue
+			}
+			for _, part := range strings.Split(line, "/") {
+				part = strings.TrimSpace(part)
+				if strings.HasSuffix(part, ".service") {
+					return part, nil
+				}
+			}
+		}
+	}
+	return "", fmt.Errorf("could not determine systemd service name from cgroup")
+}