Tax Collected page rework

Current page shows confusing fields like "pending tax" and attempts to allocate tax fractionally across partial payments. That model is wrong for the US: full tax is owed at the moment of sale, not allocated proportionally to deposits. Customers' deposits cover stone cost plus full tax in one bucket, final payment is essentially shop profit. **Simplification:** show "total tax charged" per cemetery / zone / month, drop the proportional logic and the pending-tax field. NY may differ (memorials and lettering exempt, services taxed) so state-by-state rules still need researching before launch.