- Set DNS resolvers via systemd-resolved after flushDns on connect (vpnConnection.cpp)
- RevertLink after systemd-resolved restart on disconnect (DnsUtilsLinux)
- Add scheduleRetry() to retry full DNS setup on D-Bus transient failures
- Reduce D-Bus call timeout to 5s; use systemctl restart for flushDns
- Guard maybeUpdateResolvers with #ifndef Q_OS_LINUX to preserve macOS/Windows DNS