diff --git a/proto/src/__tests__/cms-editor-client.test.ts b/proto/src/__tests__/cms-editor-client.test.ts
new file mode 100644
index 0000000..21748e7
--- /dev/null
+++ b/proto/src/__tests__/cms-editor-client.test.ts
@@ -0,0 +1,91 @@
+/**
+ * Regression test for the Content Editor browser script: deleting an array
+ * item via its ❌ button must reindex the remaining items, otherwise collect()
+ * produces sparse arrays (null holes) that fail schema validation
+ * ("$.details.services[1].specs.items[0]: string érték szükséges").
+ *
+ * Runs the REAL scripts/cms-editor-client.js in jsdom and clicks the actual
+ * delete buttons — earlier coverage only exercised reindexItems() directly,
+ * which missed that the onclick handler removed the node BEFORE looking up
+ * its container (detached node → closest() === null → no reindex).
+ */
+import fs from 'fs'
+import path from 'path'
+
+const clientJs = fs.readFileSync(path.join(__dirname, '../../../scripts/cms-editor-client.js'), 'utf8')
+
+const service = (n: number) => ({
+  id: `svc-${n}`,
+  title: `Szolgáltatás ${n}`,
+  description: `Leírás ${n}`,
+  icon: '🔧',
+  features: [`feature ${n}`],
+  ctaText: 'CTA',
+})
+
+const makeData = () => ({
+  details: {
+    title: 'Részletek',
+    subtitle: 'Alcím',
+    services: [
+      { icon: 'a', title: 's0', description: 'd0', specs: { title: 't0', items: ['a0', 'b0', 'c0'] } },
+      { icon: 'b', title: 's1', description: 'd1', specs: { title: 't1', items: ['a1', 'b1', 'c1'] } },
+      { icon: 'c', title: 's2', description: 'd2', specs: { title: 't2', items: ['a2', 'b2', 'c2'] } },
+    ],
+  },
+})
+
+function bootClient(data: unknown) {
+  ;(global as any).DATA = data
+  ;(global as any).FILE = 'services'
+  ;(global as any).CSRF_TOKEN = 'test-token'
+  ;(global as any).fetch = jest.fn()
+  document.body.innerHTML = '<div id="editor"></div>'
+  // sloppy-mode eval publishes the script's functions on the global object
+  ;(0, eval)(clientJs)
+}
+
+function deleteButtonFor(dataPath: string): HTMLButtonElement {
+  const field = document.querySelector(`[data-path="${CSS.escape(dataPath)}"]`) as HTMLElement
+  expect(field).not.toBeNull()
+  const wrap = field.closest('.str-item') as HTMLElement
+  expect(wrap).not.toBeNull()
+  return wrap.querySelector('.btn-del') as HTMLButtonElement
+}
+
+afterEach(() => {
+  delete (global as any).DATA
+  delete (global as any).FILE
+  delete (global as any).CSRF_TOKEN
+})
+
+describe('Content Editor client delete/reindex', () => {
+  it('deleting a nested string array item keeps the remaining items dense', () => {
+    const data = makeData()
+    bootClient(data)
+
+    deleteButtonFor('details.services[1].specs.items[0]').click()
+
+    const collected = (global as any).collect()
+    expect(collected.details.services[1].specs.items).toEqual(['b1', 'c1'])
+    expect(collected.details.services[0].specs.items).toEqual(['a0', 'b0', 'c0'])
+    expect(collected.details.services[2].specs.items).toEqual(['a2', 'b2', 'c2'])
+  })
+
+  it('deleting an object card reindexes the outer array', () => {
+    const data = makeData()
+    bootClient(data)
+
+    const cardHeader = Array.from(document.querySelectorAll('.card-header'))
+      .find(h => h.textContent === 'details.services[1]') as HTMLElement
+    expect(cardHeader).not.toBeNull()
+    const card = cardHeader.closest('.obj-card') as HTMLElement
+    ;(card.querySelector('.btn-del-card') as HTMLButtonElement).click()
+
+    const collected = (global as any).collect()
+    expect(collected.details.services).toHaveLength(2)
+    expect(collected.details.services[0].title).toBe('s0')
+    expect(collected.details.services[1].title).toBe('s2')
+    expect(collected.details.services[1].specs.items).toEqual(['a2', 'b2', 'c2'])
+  })
+})
diff --git a/scripts/cms-editor-client.js b/scripts/cms-editor-client.js
index 22c53ea..d904953 100644
--- a/scripts/cms-editor-client.js
+++ b/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;
 }