[econ] fix some storefronts

apps/econ/migrations/0028_catalog_listing.sql

@@ -0,0 +1,15 @@
+-- The served store listing behind a catalog row, verbatim as JSON: the `StoreItems[]` entry
+-- of `static/storefronts/sf3-2025.json` whose `PurchasableItemId` is the row's `catalog_id`.
+--
+-- `POST /api/storefronts/v1/purchasableitems` answers with whole listings — prices, item set,
+-- `AvatarItemInfo` and the rest — which the catalog's own columns do not carry. Keeping the
+-- listing on the row lets that lookup be one indexed query instead of fetching and parsing the
+-- 4 MB storefront file per request.
+--
+-- Filled by `runx catalog load`, like every other column. NULL on a row the served store does
+-- not list (the same rows whose `catalog_id` is NULL), and until the first load after this
+-- migration.
+--
+-- Its own migration because 0015 and 0016 are already applied.
+
+ALTER TABLE catalog ADD COLUMN listing TEXT;