Add support for a confluent=<host> kernel argument in init-premount: configure networking, flush interfaces, autodetect the primary NIC (saved to /tmp/autodetectnic), verify TLS connectivity to the provided server, call the whoami endpoint over TLS to obtain the node name, and write results to /custom-installation/confluent/confluent.info (with fallback to copernicus on failure).
Also update casper-bottom logic to handle IPv4 manager addresses: for IPv6 the manager is still bracketed and scoped interface resolved as before; for IPv4 the script now uses the previously detected NIC (/tmp/autodetectnic) or falls back to an `ip route get <mgr>` lookup to determine DEVICE. This ensures routed IPv4 deployments work correctly.
Ubuntu 22.04 makes some changes, notably removing the
custom-installation hooks.
Change to injecting our modifications more directly to where the
custom-installation hooks used to be.