If you've shipped a production system that handles structured data — API payloads, form submissions, config files, event streams — you've probably hit this exact wall: Your validation logic works beautifully in development. Tests pass. Types check out. You ship it. Then three weeks later, at 2am, something breaks. Not because your code is wrong, but because a piece of real-world data showed up that you never anticipated, and your validation layer had no way to tell you why it failed, where...