Rebuild the editor around one sidebar and play motion by default in 1.11.0

The editor follows the Flatsome UX Builder: dark top bar with the device
switch, one sidebar with tabs for elements, structure and page, an element
view with breadcrumbs, property tabs and actions, element cards, a context
menu in the preview and keyboard shortcuts that also work inside the preview.

Entrance and hover effects play for every visitor unless the website chooses
to respect the browser's reduced-motion preference (setting "motion", class
"motion-respect" on <html>). Waiting blocks stay hidden until they scroll into
view and are shown at once when the reader jumps past them.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

public/assets/site.css

@@ -364,10 +364,10 @@ body.consent-open{padding-bottom:260px}
 /* Solange der Einwilligungsdialog unten steht, würde der Knopf darauf liegen. */
 body.consent-open .scroll-top{display:none}
 @supports (animation-timeline: scroll()){
-    @media (prefers-reduced-motion: no-preference){
-        .scroll-top{animation:kant-scroll-top linear both;animation-timeline:scroll(root);animation-range:var(--kant-top-after,400px) calc(var(--kant-top-after,400px) + 160px)}
-        @keyframes kant-scroll-top{from{opacity:0;visibility:hidden;transform:translateY(10px)}to{opacity:1;visibility:visible;transform:none}}
-    }
+    .scroll-top{animation:kant-scroll-top linear both;animation-timeline:scroll(root);animation-range:var(--kant-top-after,400px) calc(var(--kant-top-after,400px) + 160px)}
+    @keyframes kant-scroll-top{from{opacity:0;visibility:hidden;transform:translateY(10px)}to{opacity:1;visibility:visible;transform:none}}
+    /* Beachtet die Website die Browservorgabe (Einstellungen → Bewegung), steht er von Anfang an da. */
+    @media (prefers-reduced-motion: reduce){html.motion-respect .scroll-top{animation:none}}
 }
 /* Der Bildbetrachter. Die Fläche daneben schließt, das Bild bleibt in seinen Grenzen, und die
    Bedienknöpfe sind groß genug für einen Daumen. Ohne Skript wird nichts davon gebraucht - dann