ProductChaengi: Keep product decisions current from PRD to implementation

I started building ProductChaengi after noticing that I rarely lacked documents. The problem was that each document and AI session carried a slightly different version of the product. By implementation time, I was reconstructing which decision was current. I first talked too much about one feature: reusing development context only while its file manifest is unchanged. That helps, but the larger goal is to carry reviewed product decisions from PRD through implementation. AI can prepare drafts; the human-approved version is the standard. The workflow is live and verified in isolation. I have not yet collected enough outside-user evidence to claim where it saves the most time. I would genuinely like to hear where your product context breaks first.