The dev container image generated a TLS keypair at build time and
shipped it inside the image, so every pull of the same image tag was
serving the same private key. The entrypoint also reverted to USER 0
to support a dead `createusers.txt` loop and a `chmod u+s` that was a
no-op (set on a binary owned by 1001). Net result was that any RCE
in the gateway landed as root and the wire-trust posture relied on a
shared private key.
Stop generating the cert at build time: the runtime image now carries
openssl and the entrypoint mints an ephemeral self-signed cert at
first start when no cert is mounted at the configured path. Each
container instance gets its own key. Drop USER 0 entirely; the
entrypoint runs as 1001 throughout. Prune the dead createusers loop
and the `chmod u+s`.
Separately, the README and the dev compose files publish a small set
of literal placeholder values for SessionKey, SessionEncryptionKey,
and the various Token*Key fields. Operators copy-paste these into
real deployments. Refuse to start when any of those literals appear
in the corresponding config field.
