Implement schedule WYSIWYG and UTC dates

src/web/public/css/theme-custom.css

@@ -725,6 +725,10 @@ td[data-label="Slides"] {
   position: relative;
 }
 
+.slide-editor-sidebar {
+  align-self: start;
+}
+
 .slide-form-stack {
   display: grid;
   gap: 1rem;
@@ -1734,6 +1738,11 @@ html[data-bs-theme='dark'] .template-field-card .tox .tox-collection {
     position: static;
   }
 
+  .slide-editor-sidebar {
+    position: static;
+    top: auto;
+  }
+
   .slide-editor-shell {
     grid-template-columns: minmax(0, 1fr);
   }