0xsha/KindaRails2Shell ? reverse-engineered prompt

Build me a small Python tool and local Docker lab that demonstrates a Rails Active Storage vulnerability safely on localhost. I want one self contained script that can check a target, read a file, look for secrets, probe whether it is vulnerable, and in the conditional case show how command execution could happen after recovering the signing secret. It should be easy to run from the command line, use only the Python standard library for the main tool, and have clear help text for the different modes.

Also set up a simple Rails lab in Docker that I can start and stop locally, with the app bound to localhost and running as an unprivileged user. Include a few test and research helpers if needed, plus a matrix style script that can verify vulnerable and fixed versions behave differently. Keep it focused on authorized testing and make the default output safe and readable, with secrets redacted unless I ask to show them fully.