5G Proxy Client

Fix: IPv6 link-local detection (fe80::/10) now compares the numeric value of the first hextet instead of a textual prefix, so an address such as fe8::1 is no longer misread as link-local and dropped — it is really 0fe8::, which is outside fe80::/10 (over-filtering reported in the F-Droid 1.6.5 review; the existing test had asserted the buggy behaviour)

Fix: after a network change, the DNS servers used to re-resolve the proxy server's hostname were the tunnel's own advertised servers (8.8.8.8 / 1.1.1.1 by default), not the DNS of the network the tunnel actually runs over. The intended "fall back to the local network's DHCP DNS" step had never taken effect, because it read the active network — which, for a VPN app, is its own VPN network. The underlying network's resolver is now tried first, so the hostname is not handed to a third-party resol