We faced a recurring issue in our content generation pipeline: the LLM frequently outputted malformed Markdown. Unclosed code blocks, broken list levels—you name it. Relying solely on Prompt engineering became a game of whack-a-mole that we couldn't win. The core problem? Asking an LLM to generate Markdown is a probabilistic process. A Prompt is a "soft constraint." No matter how well you phrase it, a slight token fluctuation can break the syntax, causing frontend crashes. The Shift: Data vs. Pr