The -a TASKbeforeSUBTASK syntax expanded the argument into a single
TASKNUMBER="TASK SUBTASK" (sed 's/before/ /g'). That value flowed into
every task command, not just gita add: gita show "427330 200" was
forwarded as girar-show "427330 200@", which girar-show rejects with
"bad argument", and task rm/task run would break the same way.

Split the argument into TASKNUMBER (task only) and SUBTASK, and pass
SUBTASK only to gita add (the one place where "before subtask" is
meaningful). show/run/rm now receive the bare task number.