commerce: catalog facts + multidirectional relations + conformance harness (16 tests)

catalog.sx — catalog snapshot (products/variants/stock as fact tuples),
relational accessors (producto/varianto/stocko, derived priceo/classo/
unit-priceo) usable forward and backward, deterministic catalog-price/
-class/-has? helpers. Money is integer minor units. conformance.sh runs
suites on the miniKanren stack and emits scoreboard.{json,md}.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

plans/commerce-on-sx.md

@@ -21,7 +21,7 @@ reconciliation — all auditable via the event log.
 
 ## Status (rolling)
 
-`bash lib/commerce/conformance.sh` → **0/0** (not yet started)
+`bash lib/commerce/conformance.sh` → **16/16** (1 suite: catalog)
 
 ## Ground rules
 
@@ -55,7 +55,7 @@ lib/commerce/api.sx ── (commerce/add) (commerce/total) (commerce/checkout)
 ```
 
 ## Phase 1 — Catalog + cart + deterministic totals
-- [ ] `catalog.sx` — product/variant/stock as facts
+- [x] `catalog.sx` — product/variant/stock as facts
 - [ ] `cart.sx` — line items, add/remove/qty
 - [ ] `price.sx` — base pricing relation, subtotal; tax
 - [ ] `api.sx` + tests + scoreboard + conformance.sh
@@ -76,7 +76,13 @@ lib/commerce/api.sx ── (commerce/add) (commerce/total) (commerce/checkout)
 - [ ] tests: webhook replay, partial refund, double-charge guard
 
 ## Progress log
-(loop fills this in)
+- 2026-06-06 — `catalog.sx`: catalog snapshot (products/variants/stock as fact
+  tuples) + multidirectional accessor relations (`producto`/`varianto`/`stocko`,
+  derived `priceo`/`classo`/`unit-priceo`) + deterministic `catalog-price`/
+  `-class`/`-has?` helpers. `conformance.sh` harness + scoreboard. catalog suite
+  16/16. Gotcha: minikanren `run-n` macro binds `s` internally — query vars must
+  avoid `s`; tests compare reified results with `=` (not `equal?`, which fails on
+  reified lists). Money = integer minor units throughout.
 
 ## Blockers
-(loop fills this in)
+(none)