Feed validation, health scores and analytics

Feeds are now checked on every build. Mi Auto Sync validates VINs, flags zero prices, duplicate vehicles and columns that are always or mostly blank, catches formulas that reference columns your file doesn’t have, and scores each rooftop’s feed health, so problems show up in the dashboard before they show up as disapprovals.

Run history records every feed build and delivery, and analytics show pulls, failures and rows delivered per day for every feed.