seo-ecommerce (M18)

Conditional commerce module: it only runs when commerce signals are detected, then audits and completes product structured data. Reference: references/schema-tier1.md (Product + Offer, Review/AggregateRating rows).

Audits

Working from the PageSnapshot (rendered_dom if present, else raw_html):

1. Commerce gate: detect commerce signals (price/currency text, add-to-cart/buy controls, Product/Offer schema, og:type=product). If none, every M18 finding is not_applicable (severity 0) — do not force product schema onto non-commerce pages.
2. Product + Offer: Product has name, image; Offer has price, priceCurrency, availability (schema.org/InStock etc.). Per references/schema-tier1.md.
3. AggregateRating / Review: if ratings are visibly shown, expect AggregateRating (ratingValue, reviewCount/bestRating) and/or Review (author). Never mark up ratings not visible on the page.
4. Page → schema → feed consistency (Tier 2): schema price/priceCurrency/availability must match visible on-page values and the Merchant Center feed. Mismatches risk disapproval and lost rich results.
5. Faceted navigation: filter/sort URLs (?color=, ?sort=) should canonicalize to the clean product/category URL or be noindex, to avoid index bloat and duplicate-content dilution.
6. Variants / ProductGroup: multi-variant products should use ProductGroup with hasVariant and variesBy, not duplicate standalone Product blocks per SKU.

Fixes

• AUTO (fixable: auto): generate complete, valid Product/Offer/AggregateRating JSON-LD inferred from the DOM (name, image, price, currency, availability, visible rating) inside a single @graph with a stable @id. The block is a diff for fix.
• PROPOSED (fixable: proposed): canonical/noindex tags for faceted URLs and ProductGroup restructuring — drafts requiring per-item accept.
• ADVISORY (fixable: advisory): price / availability mismatches between page, schema, and feed — the store backend/feed is the source of truth, so the tool never writes these. Never invent prices, currencies, availability, or ratings — ask the user or leave a clearly-marked TODO placeholder.