Augment a single Product. Idempotent — when format_options[] is
already present (the seller is v2-native), passes the Product
through unchanged. Otherwise projects from format_ids[].
Returns { product, diagnostics }. diagnostics is empty for a
clean projection; populated when individual format_ids don't have
a v2 mapping (catalog gap, structural unreachability, etc.).
Augment a single Product. Idempotent — when
format_options[]is already present (the seller is v2-native), passes the Product through unchanged. Otherwise projects fromformat_ids[].Returns
{ product, diagnostics }.diagnosticsis empty for a clean projection; populated when individual format_ids don't have a v2 mapping (catalog gap, structural unreachability, etc.).