Close the UI-review follow-ups: names typeahead, fleet form, overflow flip.

Staff pages typeahead customers by name (Ada, not cust_1). Add-machine is
two rows with a wide identity path and filename picker. Overflow menus
flip up near the viewport edge. Customer list no longer leaks password
hashes. UI-REVIEW.pdf remaining list is the three leftover items.

packages/zappier-accounting-export/src/names.js

@@ -1,4 +1,16 @@
 /** Join ledger ids to zappier-edge customer display names. */
+export async function listCustomers(edge, key) {
+  try {
+    const r = await fetch(`${edge.replace(/\/$/, '')}/admin/api/customers`, {
+      headers: { 'x-admin-key': key },
+    });
+    const body = await r.json();
+    return (body.customers || []).map(({ passwordHash, apiKey, totpSecret, ...rest }) => rest);
+  } catch {
+    return [];
+  }
+}
+
 export async function withCustomerName(st, idOrName, edge, key) {
   const out = { ...(st || {}) };
   if (out.name && out.customerId) return out;