updated wording

backend/migrations/0005_currency_override.sql

@@ -0,0 +1,6 @@
+-- Manual currency override for items whose auto-detected currency is wrong.
+-- Some Shopify shops price an item identically in base and presentment currency
+-- (e.g. $49.90 == €49.90), which makes the conversion heuristic mislabel it.
+-- When set, this wins over the fetched currency on every refetch and display.
+ALTER TABLE items
+    ADD COLUMN currency_override TEXT;