refactor(ui): shared searchable CustomerPicker across offers/invoices/issued-orders

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/admin/pages/IssuedOrderDetail.tsx

@@ -56,6 +56,7 @@ import {
   ConfirmDialog,
   LoadingState,
   PageEnter,
+  CustomerPicker,
   headerActionsSx,
 } from "../ui";
 import {
@@ -690,12 +691,11 @@ export default function IssuedOrderDetail() {
     });
   };
 
-  const selectCustomer = (val: string) => {
-    const cid = val ? Number(val) : null;
-    const c = customers.find((x: Customer) => x.id === cid);
+  const selectCustomer = (id: number | null) => {
+    const c = id != null ? customers.find((x: Customer) => x.id === id) : null;
     setForm((prev) => ({
       ...prev,
-      customer_id: cid,
+      customer_id: id,
       customer_name: c?.name || "",
     }));
     setErrors((prev) => ({ ...prev, customer_id: "" }));
@@ -956,19 +956,13 @@ export default function IssuedOrderDetail() {
             }}
           >
             <Field label="Dodavatel" error={errors.customer_id} required>
-              <Select
-                value={form.customer_id ? String(form.customer_id) : ""}
+              <CustomerPicker
+                customers={customers}
+                value={form.customer_id}
                 onChange={selectCustomer}
                 disabled={!editable}
-                options={[
-                  { value: "", label: "— Vyberte dodavatele —" },
-                  ...customers.map((c: Customer) => ({
-                    value: String(c.id),
-                    label: c.company_id
-                      ? `${c.name} (${c.company_id})`
-                      : c.name,
-                  })),
-                ]}
+                error={errors.customer_id}
+                placeholder="Vyberte dodavatele…"
               />
             </Field>
             <Field label="Datum objednávky" error={errors.order_date} required>