Fix refund amount calculations to prevent rounding errors and ensure partial refunds stay under 50%

For full refunds, use the order's actual total instead of summing line items to avoid rounding discrepancies that created tiny 0.01 refunds. For partial refunds, ensure the total stays below 50% of the order total by removing items if needed, preventing two partial refunds from fully refunding an order.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: layoutd

includes/Generator/Order.php

@@ -521,9 +521,46 @@ protected static function create_refund( $order, $force_partial = false ) {
 			}
 		}
 
+		// For full refunds, use the order's actual remaining total to avoid rounding discrepancies
+		if ( $is_full_refund ) {
+			$refund_amount = $order->get_total() - $order->get_total_refunded();
+		}
+
 		// Round refund amount to 2 decimal places for currency precision
 		$refund_amount = round( $refund_amount, 2 );
 
+		// For partial refunds, ensure refund is < 50% of order total by removing items if needed
+		if ( ! $is_full_refund ) {
+			$max_partial_refund = $order->get_total() * 0.5;
+
+			// If refund exceeds 50%, remove items until it's under 50%
+			while ( $refund_amount >= $max_partial_refund && count( $line_items ) > 1 ) {
+				// Remove a random item from the refund
+				$item_id_to_remove = array_rand( $line_items );
+				$removed_item = $line_items[ $item_id_to_remove ];
+				unset( $line_items[ $item_id_to_remove ] );
+
+				// Recalculate refund amount and counts
+				$refund_amount = 0;
+				$total_items = 0;
+				$total_qty = 0;
+
+				foreach ( $line_items as $item_id => $item_data ) {
+					$refund_amount += abs( $item_data['refund_total'] );
+					$total_items++;
+					$total_qty += $item_data['qty'];
+
+					if ( ! empty( $item_data['refund_tax'] ) ) {
+						foreach ( $item_data['refund_tax'] as $tax_amount ) {
+							$refund_amount += abs( $tax_amount );
+						}
+					}
+				}
+
+				$refund_amount = round( $refund_amount, 2 );
+			}
+		}
+
 		// Calculate maximum refundable amount (order total minus already refunded)
 		$max_refund = $order->get_total() - $order->get_total_refunded();
 		$max_refund = round( $max_refund, 2 );