diff --git a/runtime/lib/webdav-warmup.php b/runtime/lib/webdav-warmup.php
new file mode 100644
index 0000000..755d923
--- /dev/null
+++ b/runtime/lib/webdav-warmup.php
@@ -0,0 +1,714 @@
+<?php
+if (PHP_SAPI !== 'cli')
+{
+  http_response_code(404);
+  exit;
+}
+
+$piwigo_root = realpath(dirname(__DIR__, 3));
+if ($piwigo_root === false)
+{
+  fwrite(STDERR, "Piwigo-Root wurde nicht gefunden.\n");
+  exit(1);
+}
+define('PHPWG_ROOT_PATH', rtrim($piwigo_root, DIRECTORY_SEPARATOR).DIRECTORY_SEPARATOR);
+
+$_SERVER['REMOTE_ADDR'] = '127.0.0.1';
+$_SERVER['SERVER_ADDR'] = '127.0.0.1';
+$_SERVER['SERVER_NAME'] = 'localhost';
+$_SERVER['HTTP_HOST'] = 'localhost';
+$_SERVER['SERVER_PORT'] = '80';
+$_SERVER['REQUEST_METHOD'] = 'GET';
+$_SERVER['REQUEST_URI'] = '/';
+$_SERVER['SCRIPT_NAME'] = '/plugins/bratonien_tools/runtime/lib/webdav-warmup.php';
+$_SERVER['PHP_SELF'] = $_SERVER['SCRIPT_NAME'];
+$_SERVER['QUERY_STRING'] = '';
+$_SERVER['HTTP_USER_AGENT'] = 'Bratonien-WebDAV-Warmup/0.9.7.1.8';
+$_SERVER['HTTPS'] = 'off';
+
+require_once(PHPWG_ROOT_PATH.'include/common.inc.php');
+require_once(PHPWG_ROOT_PATH.'include/derivative.inc.php');
+
+if (!defined('BRATONIEN_TOOLS_PATH'))
+{
+  fwrite(STDERR, "Bratonien Tools ist nicht aktiv.\n");
+  exit(1);
+}
+
+require_once(BRATONIEN_TOOLS_PATH.'include/nc_connector.inc.php');
+require_once(BRATONIEN_TOOLS_PATH.'include/webdav_materialize_runtime.inc.php');
+require_once(BRATONIEN_TOOLS_PATH.'include/webdav_warmup_settings.inc.php');
+
+function bratonien_tools_warmup_log($event, array $fields=array())
+{
+  $parts = array('[BRAT-WARMUP]', $event);
+  foreach ($fields as $key => $value)
+  {
+    if (is_bool($value)) $value = $value ? '1' : '0';
+    elseif ($value === null) $value = 'NULL';
+    elseif (is_array($value) || is_object($value)) $value = json_encode($value, JSON_UNESCAPED_SLASHES);
+    $parts[] = $key.'='.str_replace(array("\r", "\n"), array('\\r', '\\n'), (string)$value);
+  }
+  fwrite(STDOUT, implode(' ', $parts)."\n");
+}
+
+function bratonien_tools_warmup_absolute_source_path(array $image_row)
+{
+  $path = (string)($image_row['path'] ?? '');
+  if ($path === '') return null;
+  if (strpos($path, '/') === 0) return $path;
+  return PHPWG_ROOT_PATH.ltrim(preg_replace('#^\./#', '', $path), '/');
+}
+
+function bratonien_tools_warmup_connection_credentials($connection_id)
+{
+  $connection = bratonien_tools_nc_connector_connection((int)$connection_id, true);
+  if (!$connection || empty($connection['enabled'])) return null;
+
+  $plain = bratonien_tools_nc_connector_decrypt_secret((string)($connection['secret_blob'] ?? ''));
+  $credentials = json_decode($plain, true);
+  if (!is_array($credentials)) return null;
+
+  $config = isset($connection['config']) && is_array($connection['config']) ? $connection['config'] : array();
+  $base_url = rtrim((string)($config['nextcloud_url'] ?? ''), '/');
+  $user = trim((string)($credentials['nextcloud_user'] ?? ''));
+  $password = (string)($credentials['nextcloud_password'] ?? '');
+  if ($base_url === '' || $user === '' || $password === '') return null;
+
+  return array(
+    'connection'=>$connection,
+    'config'=>$config,
+    'base_url'=>$base_url,
+    'user'=>$user,
+    'password'=>$password,
+  );
+}
+
+function bratonien_tools_warmup_quote_path($path)
+{
+  $parts = array_values(array_filter(explode('/', trim((string)$path, '/')), 'strlen'));
+  return implode('/', array_map('rawurlencode', $parts));
+}
+
+function bratonien_tools_warmup_download(array $source, array $credentials, $destination, &$detail=null)
+{
+  $detail = '';
+  $webdav_path = trim((string)($source['webdav_path'] ?? ''), '/');
+  if ($webdav_path === '')
+  {
+    $detail = 'WebDAV-Pfad fehlt.';
+    return false;
+  }
+
+  $fp = @fopen($destination, 'xb');
+  if (!$fp)
+  {
+    $detail = 'Temporaere Datei konnte nicht angelegt werden.';
+    return false;
+  }
+
+  $url = $credentials['base_url'].'/remote.php/dav/files/'.rawurlencode($credentials['user']).'/'.bratonien_tools_warmup_quote_path($webdav_path);
+  $ch = curl_init($url);
+  curl_setopt_array($ch, array(
+    CURLOPT_FOLLOWLOCATION => false,
+    CURLOPT_CONNECTTIMEOUT => 10,
+    CURLOPT_TIMEOUT => 300,
+    CURLOPT_HTTPAUTH => CURLAUTH_BASIC,
+    CURLOPT_USERPWD => $credentials['user'].':'.$credentials['password'],
+    CURLOPT_RETURNTRANSFER => false,
+    CURLOPT_FAILONERROR => false,
+    CURLOPT_FILE => $fp,
+    CURLOPT_USERAGENT => 'Bratonien-WebDAV-Warmup/0.9.7.1.8',
+  ));
+  $ok = curl_exec($ch);
+  $errno = curl_errno($ch);
+  $error = curl_error($ch);
+  $http = (int)curl_getinfo($ch, CURLINFO_HTTP_CODE);
+  curl_close($ch);
+  fclose($fp);
+
+  if ($ok === false || $errno !== 0 || $http < 200 || $http >= 300)
+  {
+    @unlink($destination);
+    $detail = 'Nextcloud-Download fehlgeschlagen (HTTP '.$http.', cURL '.$errno.($error !== '' ? ': '.$error : '').').';
+    return false;
+  }
+  if (!is_file($destination) || filesize($destination) < 1 || @getimagesize($destination) === false)
+  {
+    @unlink($destination);
+    $detail = 'Geladene Datei ist kein lesbares Bild.';
+    return false;
+  }
+  return true;
+}
+
+function bratonien_tools_warmup_state_file($connection_id)
+{
+  return PHPWG_ROOT_PATH.PWG_LOCAL_DIR.'bratonien-webdav-warmup.connection-'.(int)$connection_id.'.json';
+}
+
+function bratonien_tools_warmup_load_state($connection_id)
+{
+  $file = bratonien_tools_warmup_state_file($connection_id);
+  if (!is_file($file) || !is_readable($file))
+  {
+    return array('albums'=>array(), 'images'=>array(), 'updated_at'=>0);
+  }
+  $raw = @file_get_contents($file);
+  $state = $raw !== false ? json_decode($raw, true) : null;
+  if (!is_array($state)) return array('albums'=>array(), 'images'=>array(), 'updated_at'=>0);
+  if (!isset($state['albums']) || !is_array($state['albums'])) $state['albums'] = array();
+  if (!isset($state['images']) || !is_array($state['images'])) $state['images'] = array();
+  return $state;
+}
+
+function bratonien_tools_warmup_save_state($connection_id, array $state)
+{
+  $file = bratonien_tools_warmup_state_file($connection_id);
+  $directory = dirname($file);
+  if (!is_dir($directory) && !@mkdir($directory, 0775, true) && !is_dir($directory))
+  {
+    throw new RuntimeException('Warmup-State-Verzeichnis konnte nicht angelegt werden.');
+  }
+  $state['updated_at'] = time();
+  $json = json_encode($state, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES | JSON_PRETTY_PRINT);
+  if ($json === false) throw new RuntimeException('Warmup-State konnte nicht serialisiert werden.');
+  $tmp = $file.'.tmp-'.bin2hex(random_bytes(4));
+  if (@file_put_contents($tmp, $json."\n", LOCK_EX) === false) throw new RuntimeException('Warmup-State konnte nicht geschrieben werden.');
+  @chmod($tmp, 0664);
+  if (!@rename($tmp, $file))
+  {
+    @unlink($tmp);
+    throw new RuntimeException('Warmup-State konnte nicht atomar gespeichert werden.');
+  }
+}
+
+function bratonien_tools_warmup_scan_connection($connection_id)
+{
+  $images = array();
+  $albums = array();
+  $result = pwg_query('SELECT id, path, width, height, rotation, coi FROM '.IMAGES_TABLE.' ORDER BY id');
+  while ($row = pwg_db_fetch_assoc($result))
+  {
+    $image_id = (int)$row['id'];
+    $source = bratonien_tools_webdav_materialize_source_info($image_id);
+    if (!$source || (int)$source['connection_id'] !== (int)$connection_id) continue;
+
+    $row['id'] = $image_id;
+    $images[$image_id] = array('row'=>$row, 'source'=>$source, 'albums'=>array());
+  }
+
+  if (!$images) return array('images'=>array(), 'albums'=>array());
+
+  $ids = array_keys($images);
+  foreach (array_chunk($ids, 500) as $chunk)
+  {
+    $sql = 'SELECT image_id, category_id FROM '.IMAGE_CATEGORY_TABLE.' WHERE image_id IN ('.implode(',', array_map('intval', $chunk)).')';
+    $rel = pwg_query($sql);
+    while ($item = pwg_db_fetch_assoc($rel))
+    {
+      $image_id = (int)$item['image_id'];
+      $category_id = (int)$item['category_id'];
+      if (!isset($images[$image_id]) || $category_id < 1) continue;
+      $images[$image_id]['albums'][$category_id] = true;
+      $albums[$category_id] = true;
+    }
+  }
+
+  foreach ($images as &$image)
+  {
+    $image['albums'] = array_map('intval', array_keys($image['albums']));
+  }
+  unset($image);
+
+  return array('images'=>$images, 'albums'=>array_map('intval', array_keys($albums)));
+}
+
+function bratonien_tools_warmup_signature(array $source)
+{
+  return sha1(implode('|', array(
+    (int)($source['connection_id'] ?? 0),
+    (int)($source['root_fileid'] ?? 0),
+    (int)($source['fileid'] ?? 0),
+    trim((string)($source['webdav_path'] ?? ''), '/'),
+    (string)($source['etag'] ?? ''),
+    (int)($source['size'] ?? 0),
+    (int)($source['width'] ?? 0),
+    (int)($source['height'] ?? 0),
+  )));
+}
+
+function bratonien_tools_warmup_select_ids(array $scan, array $state, $mode)
+{
+  $new_albums = array();
+  $known_albums = array_fill_keys(array_map('intval', array_keys((array)$state['albums'])), true);
+  foreach ($scan['albums'] as $category_id)
+  {
+    if (!isset($known_albums[(int)$category_id])) $new_albums[(int)$category_id] = true;
+  }
+
+  $selected = array();
+  foreach ($scan['images'] as $image_id => $image)
+  {
+    $signature = bratonien_tools_warmup_signature($image['source']);
+    $known_signature = (string)($state['images'][(string)$image_id]['signature'] ?? '');
+    $in_new_album = false;
+    foreach ($image['albums'] as $category_id)
+    {
+      if (isset($new_albums[(int)$category_id]))
+      {
+        $in_new_album = true;
+        break;
+      }
+    }
+
+    if ($mode === 'sync')
+    {
+      if ($in_new_album) $selected[$image_id] = $image;
+    }
+    else
+    {
+      if ($known_signature === '' || !hash_equals($known_signature, $signature)) $selected[$image_id] = $image;
+    }
+  }
+
+  return array('images'=>$selected, 'new_albums'=>array_map('intval', array_keys($new_albums)));
+}
+
+function bratonien_tools_warmup_variants_for_stage(array $image_row, $stage)
+{
+  $src = new SrcImage($image_row);
+  $variants = array();
+  foreach (ImageStdParams::get_defined_type_map() as $type => $params)
+  {
+    $derivative = new DerivativeImage($params, $src);
+    if ($derivative->same_as_source()) continue;
+    $size = $derivative->get_size();
+    $max_edge = max((int)($size[0] ?? 0), (int)($size[1] ?? 0));
+    $is_priority = $max_edge > 0 && $max_edge <= 1920;
+    if (($stage === 1 && $is_priority) || ($stage === 2 && !$is_priority))
+    {
+      $variants[] = array('name'=>'standard:'.$type, 'derivative'=>$derivative);
+    }
+  }
+  foreach (ImageStdParams::$custom as $custom_key => $last_used)
+  {
+    $params = bratonien_tools_webdav_materialize_custom_params($custom_key);
+    if (!$params) continue;
+    $derivative = new DerivativeImage($params, $src);
+    if ($derivative->same_as_source()) continue;
+    $size = $derivative->get_size();
+    $max_edge = max((int)($size[0] ?? 0), (int)($size[1] ?? 0));
+    $is_priority = $max_edge > 0 && $max_edge <= 1920;
+    if (($stage === 1 && $is_priority) || ($stage === 2 && !$is_priority))
+    {
+      $variants[] = array('name'=>'custom:'.$custom_key, 'derivative'=>$derivative);
+    }
+  }
+  return $variants;
+}
+
+function bratonien_tools_warmup_i_url($target_path, $base_url)
+{
+  $derivative_root = PHPWG_ROOT_PATH.PWG_DERIVATIVE_DIR;
+  if (strpos($target_path, $derivative_root) !== 0) return null;
+  $location = ltrim(substr($target_path, strlen($derivative_root)), '/');
+  if ($location === '') return null;
+  $segments = array_map('rawurlencode', explode('/', $location));
+  return rtrim((string)$base_url, '/').'/i.php?/'.implode('/', $segments);
+}
+
+function bratonien_tools_warmup_call_piwigo($url, &$detail=null)
+{
+  $detail = '';
+  $ch = curl_init($url);
+  curl_setopt_array($ch, array(
+    CURLOPT_FOLLOWLOCATION => false,
+    CURLOPT_CONNECTTIMEOUT => 10,
+    CURLOPT_TIMEOUT => 300,
+    CURLOPT_RETURNTRANSFER => false,
+    CURLOPT_FAILONERROR => false,
+    CURLOPT_WRITEFUNCTION => function($ch, $data) { return strlen($data); },
+    CURLOPT_USERAGENT => 'Bratonien-WebDAV-Warmup/0.9.7.1.8',
+  ));
+  $ok = curl_exec($ch);
+  $errno = curl_errno($ch);
+  $error = curl_error($ch);
+  $http = (int)curl_getinfo($ch, CURLINFO_HTTP_CODE);
+  curl_close($ch);
+  if ($ok === false || $errno !== 0)
+  {
+    $detail = 'Piwigo-Aufruf fehlgeschlagen (cURL '.$errno.($error !== '' ? ': '.$error : '').').';
+    return false;
+  }
+  if ($http < 200 || $http >= 400)
+  {
+    $detail = 'Piwigo i.php antwortete mit HTTP '.$http.'.';
+    return false;
+  }
+  return true;
+}
+
+function bratonien_tools_warmup_acquire_sync_guard(array $credentials, &$handle=null, &$detail=null)
+{
+  $handle = null;
+  $detail = '';
+  $state_dir = rtrim((string)($credentials['config']['state_dir'] ?? ''), '/');
+  if ($state_dir === '')
+  {
+    $detail = 'State-Verzeichnis der Verbindung fehlt.';
+    return false;
+  }
+  $lock_path = $state_dir.'/webdav-sync.lock';
+  $handle = @fopen($lock_path, 'c');
+  if (!$handle)
+  {
+    $detail = 'WebDAV-Sync-Lock konnte nicht geöffnet werden.';
+    return false;
+  }
+  if (!@flock($handle, LOCK_SH | LOCK_NB))
+  {
+    fclose($handle);
+    $handle = null;
+    $detail = 'WebDAV-Synchronisierung läuft; Warmup wird später fortgesetzt.';
+    return false;
+  }
+  return true;
+}
+
+function bratonien_tools_warmup_source_lock($image_id, &$handle=null)
+{
+  $dir = PHPWG_ROOT_PATH.'upload/bratonien-webdav-materialize';
+  if (!is_dir($dir) && !@mkdir($dir, 0775, true) && !is_dir($dir)) return false;
+  $path = $dir.'/image-'.(int)$image_id.'.lock';
+  $handle = @fopen($path, 'c');
+  if (!$handle) return false;
+  return @flock($handle, LOCK_EX);
+}
+
+function bratonien_tools_warmup_release_lock(&$handle)
+{
+  if (is_resource($handle))
+  {
+    @flock($handle, LOCK_UN);
+    fclose($handle);
+  }
+  $handle = null;
+}
+
+function bratonien_tools_warmup_validate_source(array $image_row, array $source, $temp_file, &$resolved=null, &$logical=null, &$detail=null)
+{
+  $resolved = null;
+  $logical = bratonien_tools_warmup_absolute_source_path($image_row);
+  $detail = '';
+  if (!$logical)
+  {
+    $detail = 'Piwigo-Quellpfad fehlt.';
+    return false;
+  }
+  $resolved = realpath($logical);
+  if ($resolved === false || !is_file($resolved))
+  {
+    $detail = 'Piwigo-Placeholder konnte nicht aufgelöst werden.';
+    return false;
+  }
+  $normalized = str_replace('\\', '/', $resolved);
+  $expected = '/nc-webdav-source/connection-'.(int)$source['connection_id'].'/root-'.(int)$source['root_fileid'].'/';
+  if (strpos($normalized, $expected) === false)
+  {
+    $detail = 'Aufgelöster Quellpfad gehört nicht zur erwarteten Verbindung/Wurzel.';
+    return false;
+  }
+  if (!is_file($temp_file) || !is_readable($temp_file) || @getimagesize($temp_file) === false)
+  {
+    $detail = 'Batch-Quelldatei ist nicht vollständig lesbar.';
+    return false;
+  }
+  return true;
+}
+
+function bratonien_tools_warmup_restore_placeholder($resolved, $backup, $staging, &$detail=null)
+{
+  $detail = '';
+  @unlink($staging);
+  if (is_file($resolved) || is_link($resolved))
+  {
+    if (!@unlink($resolved))
+    {
+      $detail = 'Temporäre Quelle konnte beim Restore nicht entfernt werden.';
+      return false;
+    }
+  }
+  if (!is_file($backup))
+  {
+    $detail = 'Placeholder-Backup fehlt beim Restore.';
+    return false;
+  }
+  if (!@rename($backup, $resolved))
+  {
+    $detail = 'Placeholder konnte nicht restauriert werden.';
+    return false;
+  }
+  clearstatcache(true, $resolved);
+  if (!is_file($resolved) || filesize($resolved) < 1)
+  {
+    $detail = 'Restaurierter Placeholder ist nicht lesbar.';
+    return false;
+  }
+  return true;
+}
+
+function bratonien_tools_warmup_process_image(array $image, $temp_file, array $credentials, $stage, array $settings)
+{
+  $image_row = $image['row'];
+  $image_id = (int)$image_row['id'];
+
+  $source = bratonien_tools_webdav_materialize_source_info($image_id);
+  if (!$source || (int)$source['connection_id'] !== (int)$credentials['connection']['id'])
+  {
+    return array('ok'=>false, 'fatal'=>false, 'message'=>'Quellzuordnung hat sich seit Batchbeginn geändert.');
+  }
+
+  $image_lock = null;
+  if (!bratonien_tools_warmup_source_lock($image_id, $image_lock))
+  {
+    return array('ok'=>false, 'fatal'=>false, 'message'=>'Bild-Lock konnte nicht gesetzt werden.');
+  }
+
+  $sync_lock = null;
+  $detail = '';
+  if (!bratonien_tools_warmup_acquire_sync_guard($credentials, $sync_lock, $detail))
+  {
+    bratonien_tools_warmup_release_lock($image_lock);
+    return array('ok'=>false, 'fatal'=>false, 'defer'=>true, 'message'=>$detail);
+  }
+
+  $logical = null;
+  $resolved = null;
+  if (!bratonien_tools_warmup_validate_source($image_row, $source, $temp_file, $resolved, $logical, $detail))
+  {
+    bratonien_tools_warmup_release_lock($sync_lock);
+    bratonien_tools_warmup_release_lock($image_lock);
+    return array('ok'=>false, 'fatal'=>false, 'message'=>$detail);
+  }
+
+  $variants = bratonien_tools_warmup_variants_for_stage($image_row, $stage);
+  $pending = array();
+  foreach ($variants as $variant)
+  {
+    $target = $variant['derivative']->get_path();
+    if ($target !== '' && is_file($target) && is_readable($target)) continue;
+    $url = bratonien_tools_warmup_i_url($target, $settings['piwigo_base_url']);
+    if ($url !== null) $pending[] = array('name'=>$variant['name'], 'target'=>$target, 'url'=>$url);
+  }
+
+  if (!$pending)
+  {
+    bratonien_tools_warmup_release_lock($sync_lock);
+    bratonien_tools_warmup_release_lock($image_lock);
+    return array('ok'=>true, 'generated'=>0, 'message'=>'Alle Derivate der Stufe bereits vorhanden.');
+  }
+
+  $request_id = substr(bin2hex(random_bytes(8)), 0, 8);
+  $backup = $resolved.'.bratonien-placeholder-'.$request_id;
+  $staging = $logical.'.bratonien-source-'.$request_id;
+  @unlink($backup);
+  @unlink($staging);
+
+  if (!@copy($temp_file, $staging))
+  {
+    bratonien_tools_warmup_release_lock($sync_lock);
+    bratonien_tools_warmup_release_lock($image_lock);
+    return array('ok'=>false, 'fatal'=>false, 'message'=>'Batch-Quelle konnte nicht am Piwigo-Pfad bereitgestellt werden.');
+  }
+
+  $swapped = false;
+  $generated = 0;
+  try
+  {
+    if (!@rename($resolved, $backup)) throw new RuntimeException('Placeholder konnte nicht gesichert werden.');
+    if (!@rename($staging, $resolved))
+    {
+      @rename($backup, $resolved);
+      throw new RuntimeException('Temporäre Quelle konnte nicht eingesetzt werden.');
+    }
+    $swapped = true;
+    clearstatcache(true, $resolved);
+    if (@getimagesize($resolved) === false) throw new RuntimeException('Temporäre Quelle ist am Piwigo-Pfad nicht als Bild lesbar.');
+
+    foreach ($pending as $variant)
+    {
+      $call_detail = '';
+      if (!bratonien_tools_warmup_call_piwigo($variant['url'], $call_detail))
+      {
+        throw new RuntimeException($variant['name'].': '.$call_detail);
+      }
+      clearstatcache(true, $variant['target']);
+      if (!is_file($variant['target']) || !is_readable($variant['target']))
+      {
+        throw new RuntimeException($variant['name'].': Piwigo hat kein Cache-Derivat erzeugt.');
+      }
+      $generated++;
+    }
+  }
+  catch (Throwable $e)
+  {
+    $restore_detail = '';
+    $restored = $swapped ? bratonien_tools_warmup_restore_placeholder($resolved, $backup, $staging, $restore_detail) : true;
+    if (!$swapped) @unlink($staging);
+    bratonien_tools_warmup_release_lock($sync_lock);
+    bratonien_tools_warmup_release_lock($image_lock);
+    if (!$restored)
+    {
+      return array('ok'=>false, 'fatal'=>true, 'message'=>$e->getMessage().' Restore fehlgeschlagen: '.$restore_detail);
+    }
+    return array('ok'=>false, 'fatal'=>false, 'message'=>$e->getMessage());
+  }
+
+  $restore_detail = '';
+  $restored = bratonien_tools_warmup_restore_placeholder($resolved, $backup, $staging, $restore_detail);
+  bratonien_tools_warmup_release_lock($sync_lock);
+  bratonien_tools_warmup_release_lock($image_lock);
+  if (!$restored)
+  {
+    return array('ok'=>false, 'fatal'=>true, 'message'=>$restore_detail);
+  }
+
+  return array('ok'=>true, 'generated'=>$generated, 'message'=>'Piwigo-Derivate erzeugt.');
+}
+
+function bratonien_tools_warmup_run($connection_id, $mode)
+{
+  $settings = bratonien_tools_get_webdav_warmup_settings();
+  if (empty($settings['enabled']))
+  {
+    bratonien_tools_warmup_log('disabled', array('connection_id'=>$connection_id));
+    return 0;
+  }
+
+  $credentials = bratonien_tools_warmup_connection_credentials($connection_id);
+  if (!$credentials) throw new RuntimeException('WebDAV-Verbindung oder Zugangsdaten konnten nicht geladen werden.');
+
+  $state = bratonien_tools_warmup_load_state($connection_id);
+  $scan = bratonien_tools_warmup_scan_connection($connection_id);
+  $selection = bratonien_tools_warmup_select_ids($scan, $state, $mode);
+  $selected = $selection['images'];
+
+  bratonien_tools_warmup_log('scan', array(
+    'connection_id'=>$connection_id,
+    'mode'=>$mode,
+    'albums'=>count($scan['albums']),
+    'new_albums'=>count($selection['new_albums']),
+    'images'=>count($scan['images']),
+    'selected'=>count($selected),
+    'batch_size'=>$settings['batch_size'],
+  ));
+
+  if (!$selected)
+  {
+    foreach ($scan['albums'] as $category_id) $state['albums'][(string)$category_id] = array('seen_at'=>time());
+    bratonien_tools_warmup_save_state($connection_id, $state);
+    return 0;
+  }
+
+  $temp_root = PHPWG_ROOT_PATH.'upload/bratonien-webdav-warmup';
+  if (!is_dir($temp_root) && !@mkdir($temp_root, 0775, true) && !is_dir($temp_root)) throw new RuntimeException('Warmup-Temp-Verzeichnis konnte nicht angelegt werden.');
+
+  $successful = array();
+  $failed = 0;
+  $ids = array_keys($selected);
+  $batch_number = 0;
+
+  foreach (array_chunk($ids, max(1, (int)$settings['batch_size'])) as $batch_ids)
+  {
+    $batch_number++;
+    $batch_dir = $temp_root.'/connection-'.(int)$connection_id.'-'.date('YmdHis').'-'.bin2hex(random_bytes(4));
+    if (!@mkdir($batch_dir, 0775, true) && !is_dir($batch_dir)) throw new RuntimeException('Batch-Verzeichnis konnte nicht angelegt werden.');
+
+    $downloaded = array();
+    foreach ($batch_ids as $image_id)
+    {
+      $image = $selected[$image_id];
+      $source = $image['source'];
+      $temp_file = $batch_dir.'/image-'.(int)$image_id.'.img';
+      $detail = '';
+      if (bratonien_tools_warmup_download($source, $credentials, $temp_file, $detail))
+      {
+        $downloaded[$image_id] = $temp_file;
+      }
+      else
+      {
+        $failed++;
+        bratonien_tools_warmup_log('download_failed', array('image_id'=>$image_id, 'detail'=>$detail));
+      }
+    }
+
+    bratonien_tools_warmup_log('batch_downloaded', array('batch'=>$batch_number, 'requested'=>count($batch_ids), 'downloaded'=>count($downloaded)));
+
+    foreach (array(1, 2) as $stage)
+    {
+      foreach ($downloaded as $image_id => $temp_file)
+      {
+        $result = bratonien_tools_warmup_process_image($selected[$image_id], $temp_file, $credentials, $stage, $settings);
+        bratonien_tools_warmup_log('image_stage', array(
+          'batch'=>$batch_number,
+          'stage'=>$stage,
+          'image_id'=>$image_id,
+          'ok'=>!empty($result['ok']),
+          'generated'=>(int)($result['generated'] ?? 0),
+          'message'=>(string)($result['message'] ?? ''),
+        ));
+        if (!empty($result['fatal']))
+        {
+          throw new RuntimeException('Sicherheitsabbruch bei Bild #'.$image_id.': '.(string)$result['message']);
+        }
+        if (empty($result['ok']))
+        {
+          $failed++;
+          continue;
+        }
+        if ($stage === 2) $successful[$image_id] = true;
+      }
+    }
+
+    foreach ($downloaded as $temp_file) @unlink($temp_file);
+    @rmdir($batch_dir);
+  }
+
+  foreach ($scan['albums'] as $category_id) $state['albums'][(string)$category_id] = array('seen_at'=>time());
+  foreach ($successful as $image_id => $true)
+  {
+    if (!isset($scan['images'][$image_id])) continue;
+    $state['images'][(string)$image_id] = array(
+      'signature'=>bratonien_tools_warmup_signature($scan['images'][$image_id]['source']),
+      'completed_at'=>time(),
+    );
+  }
+  bratonien_tools_warmup_save_state($connection_id, $state);
+
+  bratonien_tools_warmup_log('complete', array('connection_id'=>$connection_id, 'successful'=>count($successful), 'failed'=>$failed));
+  return $failed > 0 ? 2 : 0;
+}
+
+$connection_id = 0;
+$mode = 'periodic';
+foreach ($argv as $arg)
+{
+  if (preg_match('/^--connection-id=(\d+)$/', $arg, $m)) $connection_id = (int)$m[1];
+  elseif (preg_match('/^--mode=(sync|periodic|manual)$/', $arg, $m)) $mode = $m[1];
+}
+if ($connection_id < 1)
+{
+  fwrite(STDERR, "--connection-id fehlt oder ist ungültig.\n");
+  exit(1);
+}
+
+try
+{
+  exit(bratonien_tools_warmup_run($connection_id, $mode));
+}
+catch (Throwable $e)
+{
+  fwrite(STDERR, '[BRAT-WARMUP] fatal '.$e->getMessage()."\n");
+  exit(1);
+}