Read receipt lines under the keys the receipt panel renders

The order-details panel reads qty/description/amount from
expense_metadata.line_items. A grocery shop is a receipt like any other, so it
stores the same keys rather than name/quantity/line_total — otherwise the rows
arrive complete and display blank, which is exactly the failure ING-8 names.
unit and category are the two fields a grocery line has and a delivery line does
not; nothing renders them yet and the category composition will.

src/lib/receipt-ingestion.ts

@@ -30,11 +30,17 @@ export type TenderLeg = {
   class?: "card" | "gift_card" | "cash" | null;
 };
 
+/**
+ * Same keys the order lane uses, because the panel that renders an itemised receipt reads
+ * `qty`/`description`/`amount` and a grocery shop is a receipt like any other. `unit` and
+ * `category` are the two things a grocery line has and a delivery line does not; nothing
+ * renders them yet, and the intra-transaction category composition will.
+ */
 export type ReceiptLineItem = {
-  name: string;
-  quantity?: number | null;
+  description: string;
+  qty?: number | null;
+  amount?: number | null;
   unit?: string | null;
-  line_total?: number | null;
   category?: string | null;
 };
 
@@ -103,7 +109,7 @@ export function validateReceipt(receipt: ParsedReceipt): string[] {
 
   // Lines are allowed to disagree: promotional rows are deliberately skipped during
   // extraction, so this flags rather than rejects. The money is the tender, not the lines.
-  const lineSum = round2((receipt.line_items ?? []).reduce((total, line) => total + Number(line.line_total || 0), 0));
+  const lineSum = round2((receipt.line_items ?? []).reduce((total, line) => total + Number(line.amount || 0), 0));
   if (receipt.line_items?.length && Math.abs(lineSum - round2(receipt.total)) > 0.02) flags.push(`line_items_sum_${lineSum.toFixed(2)}`);
   if (receipt.tender_legs.length > 1) flags.push("split_tender");
   if (receipt.tender_legs.some((leg) => !leg.class)) flags.push("unclassified_tender");