Support passing secrets via STDIN args instead of environment

Features

• New no_env configuration key to control mode of secret sharing
• Backwards compatible

This release consists of a new feature to avoid passing secrets as environment variables but command args. This is secure way to collect secrets instead of causing environment pollution.

env_file: .env
secret_name:  <your_secret>
vault: aws
no_env: true # New key to control no environment vs command args. Default: false

This also lets Whispr hand-off secrets to subprocess and not own anything.