sknampally/mainframe-modernization-agentic-framework ? reverse-engineered prompt

Build me a CLI tool that helps modernize a pinned mainframe codebase into a reviewed .NET on AWS plan, but keep it focused on the planning and approval workflow, not on doing the actual migration yet.

I want it to take either a GitHub repo or a local checkout, run through a four phase process for assessment, independent validation, business review, and an implementation prep package, and stop at human approval gates along the way. It should have a simple terminal menu, save workspace state, support pause and resume, and include a demo mode that runs fully offline with fake data. The output should be easy to read, show what evidence was found, what is still missing, and what needs approval. Include a sanitized CardDemo example flow and make sure the tool can generate the review artifacts and package them up clearly. Use the existing docs and prompts where helpful, and look up current docs online if you need to.