Every template install on a docker-compose v1 host failed at "Start Docker
Compose stack". The streaming path passed `--progress plain`, which v1 has no
global flag for, so it printed its entire usage text and exited 1 — the deploy
console filled with help output and nothing anywhere said the argument was the
problem. Reproduced deploying Uptime Kuma locally.
The service already detects v1 vs v2 and falls back to docker-compose; the flag
simply wasn't gated on it. `--ansi never` stays for both, since v1 does accept
that one.
Tests pin the shape rather than the symptom: v1 never receives --progress, v2
still gets plain progress, both keep their global flags before the subcommand,
and detection falls back to v1 when docker is missing entirely instead of
raising into the deploy path.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
