Add service.sh to zygisk module that resolves package names → UIDs
and writes /data/system/vpnhide_uids.txt on boot — same contract as
kmod's service.sh. This enables the lsposed system_server hooks to
work with zygisk (previously they only worked with kmod).
Also update the zygisk WebUI to resolve and write UIDs on save,
so changes apply immediately without reboot.
