- The three market Content Blocks preview as compact collapsible rows:

thumbnail of the actual image (hero background, intro image, insights
  cover), key copy in the summary line, full details expanded; card and
  intro-paragraph previews are wrapped in the same mechanism
- New SubmarketPluginPreview for vitec_usecaselist / vitec_productfeature /
  vitec_productlist: instead of bare standard boxes they now list the
  selected story titles (flagging stories that still lack a quote), the
  featured product and the hand-picked products in order
- Container-style collapse for whole page-module COLUMNS: a chevron at the
  right of every column header folds a section down to its title row,
  state kept per page and colPos in localStorage - the slot view of a
  sub-market page folds to six slim bands
- Previews sit under the page module's pointer-events lock and its
  click-to-edit layer: pointer events are re-enabled inside the collapse
  markup and the toggle runs on pointerdown in the capture phase
- Two more v14 removals fixed on the way, both latent in the OLDER preview
  classes too (Usecaseshow, Modelcard would have crashed the page module):
  GridColumnItem::getRecord() now returns a Domain\Record object, and
  StandaloneView is gone - previews normalize the record via a shared
  helper and render through the ViewFactory

packages/vitec/Resources/Public/JavaScript/backend-preview-collapse.js

@@ -0,0 +1,80 @@
+/**
+ * Collapse toggle for .vitec-collapse previews in the page module.
+ *
+ * Two defenses against the page module's own interaction layer:
+ *  - pointerdown in the CAPTURE phase toggles (fires before any click
+ *    logic TYPO3 registered earlier),
+ *  - the subsequent click on a summary is swallowed so it cannot trigger
+ *    element editing.
+ * Requires pointer-events: auto on the collapse markup (see CSS) - the
+ * module disables pointer events on preview content by default.
+ */
+(function () {
+    function summaryOf(event) {
+        return event.target instanceof Element
+            ? event.target.closest('details.vitec-collapse > summary')
+            : null;
+    }
+    document.addEventListener('pointerdown', function (event) {
+        const summary = summaryOf(event);
+        if (!summary) {
+            return;
+        }
+        event.preventDefault();
+        event.stopImmediatePropagation();
+        const details = summary.parentElement;
+        details.open = !details.open;
+    }, true);
+    document.addEventListener('click', function (event) {
+        if (summaryOf(event)) {
+            event.preventDefault();
+            event.stopImmediatePropagation();
+        }
+    }, true);
+})();
+
+/**
+ * Container-style collapse for whole page-module COLUMNS (the sub-market
+ * section slots and any other backend layout): a chevron button at the
+ * right of each column header folds the column down to its title row.
+ * State is remembered per page + colPos in localStorage.
+ */
+(function () {
+    function storageKey(colPos) {
+        const pageId = new URLSearchParams(window.location.search).get('id') || '0';
+        return 'vitecColCollapse_' + pageId + '_' + colPos;
+    }
+    function apply(column, collapsed, button) {
+        column.classList.toggle('vitec-col-collapsed', collapsed);
+        button.textContent = collapsed ? '▴' : '▾';
+        button.title = collapsed ? 'Section ausklappen' : 'Section einklappen';
+    }
+    function init() {
+        document.querySelectorAll('td.t3-page-column[data-colpos]').forEach(function (column) {
+            const header = column.querySelector('.t3-page-column-header');
+            if (!header || header.querySelector('.vitec-col-toggle')) {
+                return;
+            }
+            const colPos = column.dataset.colpos;
+            const button = document.createElement('button');
+            button.type = 'button';
+            button.className = 'vitec-col-toggle';
+            let collapsed = false;
+            try { collapsed = localStorage.getItem(storageKey(colPos)) === '1'; } catch (e) { /* egal */ }
+            apply(column, collapsed, button);
+            button.addEventListener('click', function (event) {
+                event.preventDefault();
+                event.stopPropagation();
+                const nowCollapsed = !column.classList.contains('vitec-col-collapsed');
+                apply(column, nowCollapsed, button);
+                try { localStorage.setItem(storageKey(colPos), nowCollapsed ? '1' : '0'); } catch (e) { /* egal */ }
+            });
+            header.appendChild(button);
+        });
+    }
+    if (document.readyState === 'loading') {
+        document.addEventListener('DOMContentLoaded', init);
+    } else {
+        init();
+    }
+})();