The integration seeder gave no visible progress and could hang
indefinitely. A `docker compose exec` for the admin-user step wedged on
a transient Docker-on-macOS flake, and `DockerExec.run` waited on it
with no timeout, blocking the whole UI test suite forever with no output
(stdout was block-buffered, so the existing phase prints never flushed).
- Line-buffer the seeder's stdout so phase progress streams live instead
of being dumped all at once when stdout is a pipe.
- Add numbered "[n/7] <phase> (Ns elapsed)" headers for a clear progress
and timing signal.
- Add a 60s timeout to `docker compose exec` and retry the admin-user
step, so a hung exec fails fast and recovers instead of wedging the
suite.
Reviewed-on: https://codeberg.org/secana/Forji/pulls/69
