[Feature] Hln new -s should not be unpacked in the current directory

[lyzhang1999]

# hln new -s go-gin-stack
# ls  
code  cue.mod  cue.mods  cue.sums  helm  infra  metadata.yaml  plans  README.md  schemas  stacks

now if run hln new again, This will causes the environment to be overwrite.

[hongchaodeng]

@vgjm Close this if you are done