📄️ 1. Billing OverviewHigh Level Domain📄️ 2. Billing LayersBilling Layers📄️ 3. Billing Ramp-Up1. Why a single ledger table?📄️ 4. Billing Use CasesBelow, each use case shows:🗃️ 5. Model Specifications5 items🗃️ billing-notes4 items