Attribute penetration per category. Each cell is a canonical (dimension, value) pair from CLAUDE.md §3. Click a cell to drill into the matched keyword forecasts.
Penetration = number of listings carrying this attribute / total listings in that category. Listings come from data/sample/<category>_listings.csv tagged by Gemini. Color scale is normalized per-category so each row's heatmap has visible contrast even though absolute penetration differs across categories.