Two bugs caused the log file to never be written:
1. is_service_container() used regex '^decky-\d+-\w' which only matched
the old decky-01-smtp naming style. Actual containers are named
omega-decky-smtp, relay-decky-smtp, etc. Fixed by using Docker Compose
labels instead: com.docker.compose.project=decnet + non-empty
depends_on discriminates service containers from base (sleep infinity)
containers reliably regardless of decky naming convention.
Added is_service_event() for the Docker events path.
2. The collector was only started when --api was used. Added a 'collect'
CLI subcommand (decnet collect --log-file <path>) and wired it into
deploy as an auto-started background process when --api is not in use.
Default log path: /var/log/decnet/decnet.log