fix: point customers page at /admin/customers instead of legacy path

getallcustomers/getcustomersummary still called the old
/customers/getallcustomers and /customers/getcustomersummary paths,
which 403 on api.doormile.com (auth was accepted, route wasn't valid).
Repointed both at /admin/customers per the original conversion plan.

No Doormile customer response shape has been confirmed anywhere in this
work (unlike bookings/clients/milers, which had example shapes given
up front) -- field names in customers.js (firstname/contactno/address/
customerid/etc) are still the old NearlExpress shape and left as-is
rather than guessed. Won't crash, just shows blanks for any field that
doesn't exist on a real Doormile customer. Need the actual response
body to do a real field-mapping pass, same as the login.js episode.

updateCustomer (PUT /customers/update) is still unmapped -- flagged in
a comment rather than guessed at, consistent with cancelOrder.

src/pages/nearle/customers/customers.js

@@ -352,6 +352,9 @@ export default function Customers() {
       OpenToast('Enter Longitude', 'warning', 1500);
     } else {
       try {
+        // NOTE: no Doormile "update customer" endpoint has been specified —
+        // this still calls the old /customers/update path and will fail
+        // against api.doormile.com. Left as-is rather than guessed at.
         const postUpdateResponse = await axios.put(`${process.env.REACT_APP_URL}/customers/update`, {
           customerid: selectedCustomer.customerid,
           configid: 1,