Decouple everything from globals

core/currency/currency_catalogue.gd

@@ -0,0 +1,17 @@
+class_name CurrencyCatalogue
+extends Resource
+
+@export var currencies: Array[Currency] = []
+
+func get_currency_by_id(id: StringName) -> Currency:
+	for currency in currencies:
+		if currency.id == id:
+			return currency
+	return null
+	
+func get_all_ids() -> Array[StringName]:
+	var ids: Array[StringName] = []
+	for currency in currencies:
+		if currency.id != &"":
+			ids.append(currency.id)
+	return ids

core/currency/currency_catalogue.gd.uid

@@ -0,0 +1 @@
+uid://621tus0uvbrd