diff --git a/js/nc_connector_source_ui.js b/js/nc_connector_source_ui.js
index d69b108..f923ca3 100644
--- a/js/nc_connector_source_ui.js
+++ b/js/nc_connector_source_ui.js
@@ -1,6 +1,112 @@
 (function () {
   'use strict';
 
+  function escapeHtml(value) {
+    return String(value == null ? '' : value).replace(/[&<>"']/g, function (c) {
+      return {'&':'&amp;','<':'&lt;','>':'&gt;','"':'&quot;',"'":'&#039;'}[c];
+    });
+  }
+
+  function fieldNodes(form, fieldName) {
+    return [].slice.call(form.querySelectorAll('[name="'+fieldName.replace(/"/g, '\\"')+'"]'));
+  }
+
+  function clearPickerErrors(form) {
+    [].slice.call(form.querySelectorAll('[data-source-picker-error]')).forEach(function (node) { node.remove(); });
+    [].slice.call(form.querySelectorAll('[data-source-picker-invalid="1"]')).forEach(function (field) {
+      field.removeAttribute('data-source-picker-invalid');
+      if (field.getAttribute('aria-invalid') === 'true') field.removeAttribute('aria-invalid');
+      field.style.borderColor = '';
+      field.style.boxShadow = '';
+    });
+  }
+
+  function showPickerError(form, data) {
+    clearPickerErrors(form);
+    var message = data && data.message ? data.message : 'Die Nextcloud-Ordnerauswahl konnte nicht gestartet werden.';
+    var fields = data && Array.isArray(data.fields) ? data.fields : [];
+
+    var summary = document.createElement('div');
+    summary.dataset.sourcePickerError = '1';
+    summary.className = 'bratonien-main-cache__warning';
+    summary.style.margin = '0 0 1rem';
+    summary.style.padding = '.75rem';
+    summary.style.border = '1px solid currentColor';
+    summary.innerHTML = '<strong>Ordnerauswahl nicht möglich:</strong> '+escapeHtml(message);
+    form.insertBefore(summary, form.firstChild);
+
+    var first = null;
+    fields.forEach(function (fieldName) {
+      fieldNodes(form, fieldName).forEach(function (field) {
+        field.dataset.sourcePickerInvalid = '1';
+        field.setAttribute('aria-invalid', 'true');
+        field.style.borderColor = '#d65a5a';
+        field.style.boxShadow = '0 0 0 1px #d65a5a';
+        if (!first) first = field;
+      });
+    });
+
+    if (first) {
+      first.scrollIntoView({block:'center', behavior:'smooth'});
+      window.setTimeout(function () { first.focus(); }, 150);
+    } else {
+      summary.scrollIntoView({block:'center', behavior:'smooth'});
+    }
+  }
+
+  function jsonResponse(response) {
+    return response.json().then(function (data) {
+      if (!response.ok || !data.ok) throw data;
+      return data;
+    });
+  }
+
+  function startSourcePicker(form, button) {
+    clearPickerErrors(form);
+    if (!form.reportValidity()) return;
+
+    button.disabled = true;
+    var originalText = button.textContent;
+    button.textContent = 'Verbindung prüfen …';
+
+    var saveBody = new FormData(form);
+    fetch('plugins/bratonien_tools/nc-connector-edit-save.php', {
+      method:'POST',
+      credentials:'same-origin',
+      cache:'no-store',
+      headers:{'Accept':'application/json'},
+      body:saveBody
+    })
+      .then(jsonResponse)
+      .then(function () {
+        button.textContent = 'Nextcloud-Ordner laden …';
+        var pickerBody = new FormData();
+        var token = form.querySelector('input[name="pwg_token"]');
+        var id = form.querySelector('input[name="connection_id"]');
+        pickerBody.append('pwg_token', token ? token.value : '');
+        pickerBody.append('connection_id', id ? id.value : '');
+        return fetch('plugins/bratonien_tools/nc-connector-source-picker-start.php', {
+          method:'POST',
+          credentials:'same-origin',
+          cache:'no-store',
+          headers:{'Accept':'application/json'},
+          body:pickerBody
+        }).then(jsonResponse);
+      })
+      .then(function () {
+        try {
+          sessionStorage.setItem('bratonienNcWizardMode', 'migrate');
+          sessionStorage.setItem('bratonienNcWizardOpen', '1');
+        } catch (e) {}
+        window.location.reload();
+      })
+      .catch(function (error) {
+        showPickerError(form, error && typeof error === 'object' ? error : {message:String(error), fields:[]});
+        button.disabled = false;
+        button.textContent = originalText;
+      });
+  }
+
   function enhanceMigrationButtons(root) {
     [].slice.call(root.querySelectorAll('button[value="nc_connector_migrate_start"]')).forEach(function (button) {
       button.textContent = 'Nextcloud-Ordner auswählen & migrieren';
@@ -14,6 +120,9 @@
     form.dataset.sourceUiEnhanced = '1';
 
     var headings = [].slice.call(form.querySelectorAll('h5'));
+    var webdavHeading = headings.find(function (node) {
+      return (node.textContent || '').trim() === 'Nextcloud / WebDAV';
+    });
     var legacyHeading = headings.find(function (node) {
       return (node.textContent || '').trim() === 'Bestehender Legacy-Weg';
     });
@@ -23,11 +132,29 @@
     var storageList = form.querySelector('[data-storage-list]');
     var addStorage = form.querySelector('[data-add-storage]');
 
+    if (webdavHeading && !form.querySelector('[data-webdav-source-picker]')) {
+      var webdavGrid = webdavHeading.nextElementSibling;
+      while (webdavGrid && !webdavGrid.classList.contains('bratonien-form-grid')) webdavGrid = webdavGrid.nextElementSibling;
+      if (webdavGrid) {
+        var picker = document.createElement('div');
+        picker.dataset.webdavSourcePicker = '1';
+        picker.style.margin = '.8rem 0 1rem';
+        picker.innerHTML = '<p class="bratonien-base-note" style="margin:.25rem 0 .5rem"><strong>WebDAV-Quelle:</strong> Du musst keinen Pfad kennen. Die Ordner des oben eingetragenen Nextcloud-Benutzers werden automatisch geladen und können anschließend ausgewählt werden.</p>';
+        var button = document.createElement('button');
+        button.type = 'button';
+        button.className = 'buttonLike';
+        button.textContent = 'Nextcloud-Ordner automatisch auswählen';
+        button.addEventListener('click', function () { startSourcePicker(form, button); });
+        picker.appendChild(button);
+        webdavGrid.insertAdjacentElement('afterend', picker);
+      }
+    }
+
     if (legacyHeading && !form.querySelector('[data-webdav-source-note]')) {
       var note = document.createElement('p');
       note.dataset.webdavSourceNote = '1';
       note.className = 'bratonien-main-cache__warning';
-      note.innerHTML = '<strong>Wichtig:</strong> Der folgende SMB-/lokale Speicher gehört ausschließlich zum bisherigen Legacy-Fallback. Er wird <strong>nicht</strong> als WebDAV-Quelle übernommen. Die WebDAV-Quellordner werden beim Start der Migration direkt aus Nextcloud angezeigt und ausgewählt.';
+      note.innerHTML = '<strong>Wichtig:</strong> Der folgende SMB-/lokale Speicher gehört ausschließlich zum bisherigen Legacy-Fallback. Er wird <strong>nicht</strong> als WebDAV-Quelle übernommen.';
       legacyHeading.insertAdjacentElement('beforebegin', note);
     }
 
diff --git a/main.inc.php b/main.inc.php
index c1fc095..9b803a5 100644
--- a/main.inc.php
+++ b/main.inc.php
@@ -1,7 +1,7 @@
 <?php
 /*
 Plugin Name: Bratonien Tools
-Version: 0.9.6.15
+Version: 0.9.6.16
 Description: Erweiterbare Administrationswerkzeuge fuer die Bratonien-Piwigo-Installation.
 Plugin URI: https://github.com/Terranom674/Piwigo_Bratonien_Tools
 Author: Bratonien
diff --git a/nc-connector-source-picker-start.php b/nc-connector-source-picker-start.php
new file mode 100644
index 0000000..752e396
--- /dev/null
+++ b/nc-connector-source-picker-start.php
@@ -0,0 +1,104 @@
+<?php
+$piwigo_root = realpath(dirname(__DIR__, 2));
+if ($piwigo_root === false)
+{
+  http_response_code(500);
+  exit;
+}
+define('PHPWG_ROOT_PATH', rtrim($piwigo_root, DIRECTORY_SEPARATOR).DIRECTORY_SEPARATOR);
+include_once(PHPWG_ROOT_PATH.'include/common.inc.php');
+
+header('Content-Type: application/json; charset=utf-8');
+header('Cache-Control: no-store, max-age=0');
+
+function bratonien_tools_nc_source_picker_json($status, array $payload)
+{
+  http_response_code((int)$status);
+  echo json_encode($payload, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
+  exit;
+}
+
+function bratonien_tools_nc_source_picker_fail($message, array $fields = array())
+{
+  bratonien_tools_nc_source_picker_json(422, array(
+    'ok'=>false,
+    'message'=>(string)$message,
+    'fields'=>array_values(array_unique($fields)),
+  ));
+}
+
+if (!defined('BRATONIEN_TOOLS_PATH'))
+{
+  bratonien_tools_nc_source_picker_json(404, array('ok'=>false, 'message'=>'Bratonien Tools ist nicht aktiv.', 'fields'=>array()));
+}
+if (!function_exists('is_admin') || !is_admin())
+{
+  bratonien_tools_nc_source_picker_json(403, array('ok'=>false, 'message'=>'Administratorrechte erforderlich.', 'fields'=>array()));
+}
+if (($_SERVER['REQUEST_METHOD'] ?? '') !== 'POST')
+{
+  bratonien_tools_nc_source_picker_json(405, array('ok'=>false, 'message'=>'Nur POST ist erlaubt.', 'fields'=>array()));
+}
+
+try
+{
+  check_pwg_token();
+  require_once(BRATONIEN_TOOLS_PATH.'include/tool_registry.inc.php');
+
+  $id = (int)($_POST['connection_id'] ?? 0);
+  $connection = bratonien_tools_nc_connector_connection($id, true);
+  if (!$connection)
+  {
+    bratonien_tools_nc_source_picker_fail('Die zu bearbeitende Verbindung wurde nicht gefunden.');
+  }
+  if ((string)$connection['adapter'] !== 'local')
+  {
+    bratonien_tools_nc_source_picker_fail('Die automatische Migrationsauswahl ist nur für die bestehende Legacy-Verbindung vorgesehen.');
+  }
+
+  $config = isset($connection['config']) && is_array($connection['config']) ? $connection['config'] : array();
+  $credentials = bratonien_tools_nc_connector_scoped_secret($connection);
+
+  $base_url = trim((string)($config['nextcloud_url'] ?? ''));
+  $username = trim((string)($credentials['nextcloud_user'] ?? ''));
+  $password = (string)($credentials['nextcloud_password'] ?? '');
+
+  $missing = array();
+  if ($base_url === '') $missing[] = 'nc_nextcloud_url';
+  if ($username === '') $missing[] = 'nc_nextcloud_user';
+  if ($password === '') $missing[] = 'nc_nextcloud_password';
+  if ($missing)
+  {
+    bratonien_tools_nc_source_picker_fail(
+      'Für die automatische Ordnerauswahl müssen Nextcloud-Adresse, Benutzer und Passwort gespeichert sein.',
+      $missing
+    );
+  }
+
+  bratonien_tools_nc_connector_prepare_webdav_wizard_from_connection($connection, 'migrate');
+
+  $state = bratonien_tools_nc_wizard_state();
+  if ((int)($state['step'] ?? 0) !== 2 || empty($state['scan_ok']) || empty($state['directory_selection_ready']))
+  {
+    $detail = trim((string)($state['technical_error'] ?? ''));
+    bratonien_tools_nc_source_picker_fail(
+      $detail !== '' ? 'Die Nextcloud-Ordner konnten nicht geladen werden: '.$detail : 'Die Nextcloud-Ordner konnten nicht geladen werden.',
+      array('nc_nextcloud_url','nc_nextcloud_user','nc_nextcloud_password')
+    );
+  }
+
+  bratonien_tools_nc_source_picker_json(200, array(
+    'ok'=>true,
+    'message'=>'Nextcloud-Ordner wurden geladen. Die Auswahl wird geöffnet.',
+    'fields'=>array(),
+  ));
+}
+catch (Throwable $e)
+{
+  $message = trim($e->getMessage());
+  if ($message === '') $message = 'Die Nextcloud-Ordnerauswahl konnte nicht vorbereitet werden.';
+  bratonien_tools_nc_source_picker_fail(
+    $message,
+    array('nc_nextcloud_url','nc_nextcloud_user','nc_nextcloud_password')
+  );
+}