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/i18n/default_de.json

@@ -488,6 +488,9 @@
   "Select a customer first...": "Bitte zuerst einen Kunden auswählen...",
   "Loading domains...": "Domains werden geladen...",
   "No domains found for this customer": "Keine Domains für diesen Kunden gefunden",
+  "No domains found for this customer. Enter domain name manually:": "Keine Domains für diesen Kunden gefunden. Domain-Name manuell eingeben:",
+  "Domain name (e.g. example.de)": "Domain-Name (z. B. example.de)",
+  "URL (optional, e.g. https://example.de)": "URL (optional, z. B. https://example.de)",
   "Failed to load domains": "Domains konnten nicht geladen werden",
   "Please select a domain": "Bitte wählen Sie eine Domain",
   "Delete": "Löschen",

modules/helpdesk/i18n/default_en.json

@@ -488,6 +488,9 @@
   "Select a customer first...": "Select a customer first...",
   "Loading domains...": "Loading domains...",
   "No domains found for this customer": "No domains found for this customer",
+  "No domains found for this customer. Enter domain name manually:": "No domains found for this customer. Enter domain name manually:",
+  "Domain name (e.g. example.de)": "Domain name (e.g. example.de)",
+  "URL (optional, e.g. https://example.de)": "URL (optional, e.g. https://example.de)",
   "Failed to load domains": "Failed to load domains",
   "Please select a domain": "Please select a domain",
   "Delete": "Delete",

modules/helpdesk/pages/helpdesk/handovers/create(default).phtml

@@ -149,11 +149,23 @@ if ($canManage && $mode === 'assign' && $step === 2) {
              data-initial-domain="<?php e($form['domain_no'] ?? ''); ?>"
         >
           <label for="wizard-domain"><?php e(t('Domain')); ?> <span class="handover-form-required">*</span></label>
-          <select id="wizard-domain" name="domain_no" disabled>
+          <div class="app-wizard-domain-select-wrap">
-            <option value=""><?php e(t('Select a customer first...')); ?></option>
+            <select id="wizard-domain" name="domain_no" disabled>
-          </select>
+              <option value=""><?php e(t('Select a customer first...')); ?></option>
+            </select>
+          </div>
           <input type="hidden" name="domain_url" id="wizard-domain-url" value="<?php e($form['domain_url'] ?? ''); ?>">
           <div id="wizard-domain-feedback" class="app-wizard-field-feedback" role="alert" hidden></div>
+
+          <!-- Manual entry — shown by JS when no domains exist for this customer -->
+          <div id="wizard-domain-manual" hidden>
+            <p class="app-wizard-field-hint"><?php e(t('No domains found for this customer. Enter domain name manually:')); ?></p>
+            <input type="text" id="wizard-domain-manual-no" placeholder="<?php e(t('Domain name (e.g. example.de)')); ?>"
+                   value="<?php e($form['domain_no'] ?? ''); ?>" autocomplete="off">
+            <input type="text" id="wizard-domain-manual-url" placeholder="<?php e(t('URL (optional, e.g. https://example.de)')); ?>"
+                   value="<?php e($form['domain_url'] ?? ''); ?>" autocomplete="off" style="margin-top:0.4rem;">
+          </div>
+
           <?php if (!empty($errors['domain_no'])): ?>
             <p class="field-error"><?php e($errors['domain_no']); ?></p>
           <?php endif; ?>

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) {