Events with a URL were saved with source "external", so Contao linked
lists straight to the external site and redirected the detail page.
The URL is now kept in the url field and only shown as a button on the
detail page.
- frontend form saves source "default" for every event
- backend: source option "external" removed, url field relabelled
"Externer Link", obsolete target field dropped from the palette
- migration switches existing source="external" events to "default"
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The event detail template data set has_tag_21 to drive the
Kulturhauptdorf logo, but tag 21 is "Feste & Märkte", so the logo
showed on every market/festival event. Add is_kulturhauptdorf, which
checks for a tag named "Kulturhauptdorf" (case-insensitive), and keep
has_tag_21 as deprecated for backwards compatibility.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>