Add a post-join control-plane readiness gate so a half-succeeded server
join on a degraded etcd can no longer pass as success. Retry the MetalLB
IPAddressPool/L2Advertisement applies to ride out the validating-webhook
startup race. Narrow the k3sup cleanup glob, quiet the final k3sup ready
tip, and clarify two comments.
README: add networking caveats (VIP/LB outside the DHCP pool, same-subnet
ARP/L2, interface naming), certName key placement, a post-run verification
section, machine-count/admin-box notes, and fix the RAW_BASE description.
- match the global README.md convention; update the reference in k3s.sh
- pad the options table so it reads cleanly in raw and rendered views,
kept under the 80-col markdownlint limit