-- Issue #133: PO-level TCS and Discount, shown below GST.
-- Absolute rupee amounts (nullable, default 0 so historical/imported POs read as 0).
-- totalAmount already includes these: subtotal + GST + tcsAmount - discountAmount.
ALTER TABLE "PurchaseOrder" ADD COLUMN "tcsAmount" DECIMAL(12,2) DEFAULT 0;
ALTER TABLE "PurchaseOrder" ADD COLUMN "discountAmount" DECIMAL(12,2) DEFAULT 0;