MOSCOW, May 8 : Russian dogwear entrepreneur Natalia Kukovinets has had to switch messaging apps multiple times to stay in touch with customers, one of many web-dependent businesses struggling with the Kremlin's widening internet crackdown. Restrictions on popular messenger apps such as Telegram, curbs on VPNs, and security-linked mobile internet shutdowns have affected much of Russia this year, but the unpredictable outages pose a particular headache for many small companies, with billions of