Translate the video toggle and guard loops without one

The pause and play labels were missing from the kant_t dictionary, so
English and Turkish pages showed them in German. video.js now skips a
data-video-loop without its toggle instead of throwing and leaving every
later video still, and the design panel puts size and spacing first for
the video block.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

public/assets/video.js

@@ -12,6 +12,8 @@ const saving = navigator.connection?.saveData === true;
 
 for (const video of document.querySelectorAll('[data-video-loop]')) {
   const toggle = video.parentElement.querySelector(':scope > .video-toggle');
+  // Ein data-video-loop aus „Eigenes HTML“ hat keinen Knopf; ohne ihn bleibt es beim Standbild.
+  if (!toggle) continue;
   let wanted = !reduced.matches && !saving;
   let visible = false;
   const paint = () => {