Improve shell compatibility (POSIX)
- Replaced `#!/bin/bash` with `#!/bin/sh` for POSIX compliance.
- Changed `[[ ... ]]` to `[ ... ]` for condition checks.
- Replaced `source` with `.` for shell compatibility.
- Used `type` instead of `command -v` to check `deploy`.
- Added clearer messages for `local_bin_location` creation.