fix(template-no-nested-interactive): allow interactive content in <details> body panel

During the rebase that introduced isSummaryFirstChildOfDetails, the
broader isAllowedDetailsChild check was lost. The disclosed panel of
<details> is flow content — interactive children after <summary> are
valid and must not be flagged. Restores isAllowedDetailsChild as a
wrapper that delegates the <summary>-position check to
isSummaryFirstChildOfDetails.

Author: johanrd

lib/rules/template-no-nested-interactive.js

@@ -65,6 +65,18 @@ function isSummaryFirstChildOfDetails(summaryNode, parentEntry) {
   return firstNonWhitespace === summaryNode;
 }
 
+function isAllowedDetailsChild(childNode, parentEntry) {
+  if (parentEntry.tag !== 'details') {
+    return false;
+  }
+  // Non-<summary> children are flow content in the disclosed panel — allowed.
+  if (childNode.tag !== 'summary') {
+    return true;
+  }
+  // <summary> is only allowed as the first non-whitespace child of <details>.
+  return isSummaryFirstChildOfDetails(childNode, parentEntry);
+}
+
 /** @type {import('eslint').Rule.RuleModule} */
 module.exports = {
   meta: {
@@ -223,8 +235,8 @@ module.exports = {
               });
             }
             parentEntry.interactiveChildCount++;
-          } else if (isSummaryFirstChildOfDetails(node, parentEntry)) {
-            // <summary> as first non-whitespace child of <details> is allowed
+          } else if (isAllowedDetailsChild(node, parentEntry)) {
+            // Non-<summary> children are body content; <summary> allowed only as first child
           } else if (isCompositeWidgetPattern(getRole(parentEntry.node), getRole(node))) {
             // Canonical ARIA composite-widget hierarchies — e.g. option inside
             // listbox, tab inside tablist, treeitem inside tree, row inside