rshen/Letmein was a live, checked-in cluster_admin credential in
auth.yaml. Renamed to a non-identifying username with a clearly-marked
placeholder password.
docs: add full ops deployment guide (src/docs/deployment.md)
Covers building and running all four daemons plus xceadmin, based on
direct source verification (CLI flags, config file shapes, TLS posture)
and a live single-node deploy. Documents real production gaps (no
process supervision, plaintext non-controller traffic, exposed dev
creds) rather than treating the repo as a finished runbook.
