Track token drift

Token drift is the slow accumulation of small visual deviations that nobody catches in the moment. A color is approximated from memory. A spacing value gets rounded. A border radius changes in one component but not others. Over time the brand feels off, but no single change is large enough to trigger a review. Load an extraction into the Dembrandt App and pin it as the visual baseline. After the next release cycle, run a new extraction and load it alongside. The App computes a per-token diff: what changed, by how much, what is new, what is gone. Catch drift before it compounds.