fix: expose accordion contents and add clear insert actions (1.8.3)

tests/editor-model.test.mjs

@@ -224,6 +224,17 @@ test('v6 containers accept only their own children and an accordion starts with
   assert.equal(canContain(block, { type: 'accordionitem' }), true);
   assert.equal(canContain({ type: 'section', children: [] }, { type: 'accordionitem' }), false);
   assert.equal(canContain(block.children[0], { type: 'text' }), true);
+  // Selecting the group must not silently put a text outside it. Choose the entry first.
+  assert.equal(insertionTarget(history.document, accordion, 'text'), null);
+  assert.equal(insertBlock(history.document, 'text', accordion), null);
+  const entry = block.children[0].id;
+  const text = history.change(doc => insertBlock(doc, 'text', entry));
+  assert.equal(locate(history.document.blocks, text).parent.id, entry);
+  history.undo();
+  assert.equal(locate(history.document.blocks, entry).block.children.length, 0);
+  history.redo();
+  assert.equal(locate(history.document.blocks, text).parent.id, entry);
+  history.undo();
 
   // A logo strip takes images only, like a gallery.
   const logos = history.change(doc => insertBlock(doc, 'logos', 's2'));