Add Price & Currency Fields to List Exports

🔍 Problem Statement

List exports (customers, subscriptions) do not include price or currency fields. Teams that need pricing data in their exports must cross-reference with plan data manually, adding unnecessary steps to reporting workflows.

💡 User Story

As a Pelcro admin, I want price and currency fields included in list exports, so that export files contain complete billing information without requiring manual cross-referencing.

🎯 Definition of Done (DoD)

A feature is done when:

✔️ Given a list export (customers or subscriptions), when the export is generated, then it includes the plan price and currency for each record.