[lyrixx]

Same idea as castor builder -- <command>: the castor pg task now accepts anything after -- and proxies it to psql inside the postgres container, in a non-interactive way with the exit code propagated. This makes it easy for agents (and humans) to run queries:

castor pg                          # interactive psql (unchanged)
castor pg -- "SELECT now();"       # one-shot query
castor pg -- -c "\dt"              # raw psql arguments

If the first argument is not an option (does not start with -), the words are re-joined into a single psql -c argument, as the shell splits them into multiple argv entries.