crawl: universal schema.org microdata product extraction (no per-DB code)

catalog_query: out-of-stock exists answer no longer says "we don't carry it"

router: deterministic backstop + key-retry so structured Qs survive LLM outages

mverify: adversarial stress harness (question-space coverage)

catalog_query: broaden basket detection, digit anchors, prefer-priced dedup

catalog_query: compare direction (which-costs-more names the dearer item)

mverify: live hard-tier quiz (compare/order/basket) with computation grading

catalog_query: multi-product fan-out for compare / order / basket questions