A && B || C isn't if-then-else -- C can run when A is true but B
fails too. Use an explicit if/else so an mkdir success + install
failure is still caught.
Docker on the LAN box is the snap package, sandboxed to $HOME (plus a
short allowlist) -- it can't see /etc/thermograph.env at all, so
env_file: /etc/thermograph.env silently loads nothing for every
container there, no matter how correctly the vault renders. Confirmed
directly: `docker run --env-file /etc/thermograph.env` fails with
"no such file or directory" on a file the shell reads fine; the same
file under $HOME loads correctly.
render-secrets.sh gains an opt-in second write
(THERMOGRAPH_SECRETS_ENV_FILE_MIRROR), deploy-dev.sh points it at
infra/deploy/dev-secrets.env (gitignored, re-rendered every deploy),
and docker-compose.dev.yml adds it as a second env_file entry for
backend/daemon/lake -- compose appends env_file lists across overlays,
so this is additive and prod/beta (which never set the mirror var)
are unaffected.
