Add missing POSItemIdentifier import to TotalsViewHelperTests

Fixes compilation errors where POSItemIdentifier was not found in scope.

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Co-Authored-By: Claude <[email protected]>

Author: joshheald

Modules/Tests/PointOfSaleTests/ViewHelpers/TotalsViewHelperTests.swift

@@ -1,5 +1,6 @@
 import Testing
 @testable import PointOfSale
+import struct Yosemite.POSItemIdentifier
 
 struct TotalsViewHelperTests {