feat(freight): add download for the TIN business registration record

Ticket #181 — eTrade auto-fetch already existed; adds a client-side
download of the fetched record (eTrade returns data, not a document)
on the portal onboarding step and the backoffice customer detail page.

apps/edr-freight-web/portal/src/components/onboarding/ETradeInfo.tsx

@@ -28,6 +28,31 @@ interface ETradeInfoProps {
 
 const isValidTin = (tin: string) => tin.length === 10;
 
+/** Plain-text summary of the fetched eTrade record, downloaded client-side (eTrade returns data, not a document). */
+function downloadTinRecord(tin: string, data: CompanyRegistrationData) {
+  const lines = [
+    `TIN: ${tin}`,
+    `Company name: ${data.companyName}`,
+    `Licence number: ${data.licenceNumber}`,
+    `Status: ${data.statusDescription}`,
+    `Date registered: ${data.dateRegistered}`,
+    `Renewed from: ${data.renewedFrom}`,
+    `Renewal date: ${data.renewalDate}`,
+    `Renewed to: ${data.renewedTo}`,
+    `Address: ${[data.region, data.zone, data.woreda, data.kebele, data.houseNo].filter(Boolean).join(", ")}`,
+    `Manager: ${data.managerName}`,
+  ];
+  const blob = new Blob([lines.join("\n")], { type: "text/plain;charset=utf-8" });
+  const url = URL.createObjectURL(blob);
+  const a = document.createElement("a");
+  a.href = url;
+  a.download = `tin-${tin}.txt`;
+  document.body.appendChild(a);
+  a.click();
+  a.remove();
+  setTimeout(() => URL.revokeObjectURL(url), 60_000);
+}
+
 export default function ETradeInfo({
   tin,
   register,
@@ -123,6 +148,17 @@ export default function ETradeInfo({
             {isLoading ? "Getting..." : "Get Data"}
           </Button>
         )}
+        {status === "verified" && mutation.data && !mutation.data.tinTaken && (
+          <Button
+            variant="light"
+            color="edr-green"
+            onClick={() => downloadTinRecord(tin, mutation.data!)}
+            leftSection={<Download size={16} />}
+            mt="24px"
+          >
+            Download
+          </Button>
+        )}
       </Group>
 
       {notFound && (