zinit: stabilize ntp/network/getty runtime

• ntp: robust /etc/ntp.conf symlink, safe defaults, avoid nounset, keep BusyBox CLI -p usage

• network: wrap dhcpcd to create dhcpcd user/group if missing; run as root if needed

• console: set getty console to 115200 vt100

config/zinit/ntp.yaml

@@ -1,3 +1,3 @@
 exec: sh /etc/zinit/init/ntpd.sh
 after:
-  - network
+  - network