fix(cms): capture array container before node removal so reindex runs

The ❌ delete buttons called wrap.closest('.array-items') AFTER remove();
a detached node has no ancestors, so closest() returned null and
reindexItems() silently skipped. Remaining items kept their old indices,
collect() produced sparse arrays (null holes) and saves failed schema
validation, e.g. '$.details.services[1].specs.items[0]: string érték
szükséges'. Capture the container before remove() for both str-item and
obj-card delete handlers.

Regression test runs the real browser script in jsdom and clicks the
actual delete buttons (nested string array + object card reindexing).

Closes MITHOME-67

scripts/cms-editor-client.js

@@ -116,7 +116,14 @@ function makeStrItem(val, idx, path) {
   del.className = 'btn-del';
   del.textContent = '❌';
   del.title = 'Törlés';
-  del.onclick = () => { wrap.remove(); reindexItems(wrap.closest('.array-items')); };
+  del.onclick = () => {
+    // WHY: capture the container BEFORE removing — a detached node has no
+    // ancestors, so closest() would return null and reindexing would silently
+    // not run (sparse arrays → schema errors on save).
+    const container = wrap.closest('.array-items');
+    wrap.remove();
+    reindexItems(container);
+  };
   wrap.appendChild(ta);
   wrap.appendChild(del);
   return wrap;
@@ -135,7 +142,12 @@ function makeObjCard(obj, idx, path) {
   const del = document.createElement('button');
   del.className = 'btn-del-card';
   del.textContent = '❌ Törlés';
-  del.onclick = () => { card.remove(); reindexItems(card.closest('.array-items')); };
+  del.onclick = () => {
+    // Same as above: capture before detaching, or reindexing is skipped.
+    const container = card.closest('.array-items');
+    card.remove();
+    reindexItems(container);
+  };
   card.appendChild(del);
   return card;
 }