feat(orders): show the receipt in the transaction detail panel

`expense_metadata` has held the itemised receipt since ingestion started and
nothing in the UI ever read it. A transaction that came from a DoorDash or Uber
Eats receipt showed a merchant and an amount, with the item list and the
delivery addresses sitting unread in the row behind it (user, 2026-07-27).

Adds GET /api/transactions/[id]/order and an "Order details" section in the
edit modal: line items with their options, pick-up/delivery stops with times
and addresses, the card tail when one was involved, and the provider's own
order reference.

Two details that matter:

- The lookup resolves from **both** sides — `transaction_id` OR
  `matched_transaction_id`. A card-settled order creates no transaction of its
  own (I5); the receipt points at the statement line instead. Matching only on
  transaction_id would have left the panel blank on exactly the card-paid
  orders, which are the ones whose detail is hardest to find elsewhere.
- An empty item list says so in words rather than rendering nothing. Uber
  itemises groceries but not restaurant orders, and orders ingested before the
  Uber item parser existed have none either — a blank section reads as a bug
  when it is usually the receipt.

Read-only. This is what a provider sent; editing it would make provenance mean
nothing.

src/components/edit-transaction-modal.tsx

@@ -8,6 +8,8 @@ import {
   useRemoveTransactionTag,
   useTransactionSplits,
   useTrips,
+  useOrderReceipt,
+  type OrderReceipt,
 } from "@/lib/hooks";
 import { SplitModal } from "./split-modal";
 import { CATEGORIES, formatCategory } from "@/lib/categories";
@@ -85,6 +87,89 @@ function InlineTags({ transactionId, initialTags }: { transactionId: number; ini
   );
 }
 
+const PLATFORM_LABEL: Record<string, string> = {
+  doordash: "DoorDash",
+  ubereats: "Uber Eats",
+  uber: "Uber",
+};
+
+/**
+ * The receipt behind a delivery order: what was actually bought, and where it
+ * went. All of it was already stored at ingest and none of it was reachable —
+ * the row showed a merchant and a total and nothing else.
+ *
+ * Read-only on purpose. This is what a provider sent, not something to edit.
+ */
+function OrderDetails({ transactionId, currency }: { transactionId: number; currency: string | null }) {
+  const { data: receipt, isLoading } = useOrderReceipt(transactionId);
+  if (isLoading || !receipt) return null;
+
+  const cur = receipt.currency ?? currency ?? "AUD";
+  const fmt = (n: number) => (cur === "AUD" ? `$${n.toFixed(2)}` : `${cur} ${n.toFixed(2)}`);
+  const items: OrderReceipt["line_items"] = receipt.line_items ?? [];
+  const route: OrderReceipt["route"] = receipt.route ?? [];
+
+  return (
+    <div className="border-t border-zinc-800 pt-4">
+      <div className="flex items-baseline justify-between mb-2">
+        <p className="text-xs text-zinc-500">
+          Order details
+          {receipt.platform && (
+            <span className="ml-1.5 text-zinc-400">{PLATFORM_LABEL[receipt.platform] ?? receipt.platform}</span>
+          )}
+        </p>
+        {receipt.card_last4 && (
+          <span className="text-xs text-zinc-600">card ••••{receipt.card_last4}</span>
+        )}
+      </div>
+
+      {items.length > 0 ? (
+        <ul className="space-y-1.5 mb-3">
+          {items.map((it, i) => (
+            <li key={i} className="flex gap-2 text-xs">
+              <span className="text-zinc-600 tabular-nums shrink-0">{it.qty}×</span>
+              <span className="text-zinc-300 flex-1 min-w-0">
+                {it.description}
+                {it.options && it.options.length > 0 && (
+                  <span className="block text-zinc-600">{it.options.join(" · ")}</span>
+                )}
+              </span>
+              <span className="text-zinc-400 tabular-nums shrink-0">{fmt(Number(it.amount))}</span>
+            </li>
+          ))}
+        </ul>
+      ) : (
+        // Uber itemises groceries but not restaurant orders, and orders taken
+        // before this was parsed have none either. Say which, rather than
+        // showing an empty list that reads like a bug.
+        <p className="text-xs text-zinc-600 italic mb-3">
+          No itemised list on this receipt
+        </p>
+      )}
+
+      {route.length > 0 && (
+        <div className="space-y-1">
+          {route.map((pt, i) => (
+            <div key={i} className="flex gap-2 text-xs">
+              <span className="text-zinc-600 shrink-0 w-24">
+                {pt.label}
+                {pt.time && <span className="block text-zinc-700">{pt.time}</span>}
+              </span>
+              <span className="text-zinc-400 flex-1">{pt.address}</span>
+            </div>
+          ))}
+        </div>
+      )}
+
+      {receipt.order_reference && !receipt.order_reference.startsWith("msg:") && (
+        <p className="mt-3 text-[11px] text-zinc-700 font-mono break-all">
+          {receipt.order_reference}
+        </p>
+      )}
+    </div>
+  );
+}
+
 export function EditTransactionModal({
   transaction,
   onClose,
@@ -314,6 +399,8 @@ export function EditTransactionModal({
               )}
             </div>
 
+            <OrderDetails transactionId={transaction.id} currency={transaction.currency ?? null} />
+
           </div>
 
           {/* Footer */}