feat(helpdesk): show manual domain input when customer has no domains

When the domain API returns an empty list for a selected customer, the
domain select is replaced with two text inputs: domain name (required)
and URL (optional). JS syncs the manual values into the existing hidden
domain_no/domain_url fields so the server-side validation and save logic
is unchanged.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

modules/helpdesk/web/js/handover-domain-select.js

@@ -25,6 +25,9 @@ export function initHandoverDomainSelect(root = document) {
   const domainSelect = group.querySelector('#wizard-domain');
   const domainUrlInput = group.querySelector('#wizard-domain-url');
   const feedback = group.querySelector('#wizard-domain-feedback');
+  const manualBlock = group.querySelector('#wizard-domain-manual');
+  const manualNoInput = group.querySelector('#wizard-domain-manual-no');
+  const manualUrlInput = group.querySelector('#wizard-domain-manual-url');
   if (!lookupContainer || !domainSelect) {
     return EMPTY_API;
   }
@@ -67,6 +70,24 @@ export function initHandoverDomainSelect(root = document) {
     feedback.dataset.variant = variant || '';
   };
 
+  const showManual = (show) => {
+    if (!manualBlock) {
+      return;
+    }
+    manualBlock.hidden = !show;
+    domainSelect.closest('.app-wizard-domain-select-wrap')?.toggleAttribute('hidden', show);
+    if (!show && manualNoInput) {
+      manualNoInput.value = '';
+    }
+    if (!show && manualUrlInput) {
+      manualUrlInput.value = '';
+    }
+    // When showing manual, clear the hidden domain_no/url so only manual values submit
+    if (show && domainUrlInput) {
+      domainUrlInput.value = '';
+    }
+  };
+
   const resetDomain = () => {
     clearOptions();
     addPlaceholder(textInitial);
@@ -75,6 +96,7 @@ export function initHandoverDomainSelect(root = document) {
       domainUrlInput.value = '';
     }
     setFeedback('', '');
+    showManual(false);
   };
 
   const loadDomains = async (debitorNo) => {
@@ -95,9 +117,11 @@ export function initHandoverDomainSelect(root = document) {
 
       if (items.length === 0) {
         domainSelect.disabled = true;
-        setFeedback(textEmpty, 'warning');
+        setFeedback('', '');
+        showManual(true);
         return;
       }
+      showManual(false);
 
       items.forEach((item) => {
         const opt = document.createElement('option');
@@ -126,6 +150,23 @@ export function initHandoverDomainSelect(root = document) {
     }
   });
 
+  // Sync manual inputs → hidden domain_no / domain_url fields
+  if (manualNoInput) {
+    on(manualNoInput, 'input', () => {
+      const hiddenNo = scope.querySelector('input[name="domain_no"]');
+      if (hiddenNo) {
+        hiddenNo.value = manualNoInput.value.trim();
+      }
+    });
+  }
+  if (manualUrlInput) {
+    on(manualUrlInput, 'input', () => {
+      if (domainUrlInput) {
+        domainUrlInput.value = manualUrlInput.value.trim();
+      }
+    });
+  }
+
   on(lookupContainer, 'lookup:select', (event) => {
     const debitorNo = event.detail?.value || '';
     if (debitorNo) {