The presence of `process.argv[1]` in the current invocation does not
imply that the current `pi` process is being invoked as a script.
Specifically, in the case of a bun compiled binary, `process.argv[1]`
will be the virtual path `/$bunfs/root/pi`, which is not a real file on
the filesystem. This causes the subagent extension to inject this path
into the child `pi` invocation, which is interpreted as part of the
prompt, which confuses the subagent.
This change uses the script only if it is not a bunfs virtual script
Co-authored-by: nathyong <nathyong@noreply.github.com>
