* instant (dev) sandbox
* leave Dockerfile as is to pass deploy test
* fix comma
* fix prod build
* do not use "images exists" which docker does not support
* separate dev-mode flag
* Merge remote-tracking branch 'origin/main' into instant_sandbox
* shell bones
* Merge remote-tracking branch 'origin/main' into shell_bones
* add line break
* another line break
* drop the log to avoid breaking terminals
* rename tool to be consistent with terminal
* fix build
If `nounset` is active, it'll require that TERM and COLORTERM is set in the
environment. It's not necessary that these variables are set and it should be
passed to the sandbox. This change just causes the TERM and COLORTERM to be set
to an empty string if they are unset.
