fix(widgets): prevent TabsContainer state reset on data refetch

react-jsx-parser auto-generates random keys on every render, causing
full remounts that reset uncontrolled Tabs to defaultValue. Fix by:
- Adding disableKeyGeneration to preserve React reconciliation
- Memoizing bindings to avoid unnecessary re-parses
- Converting TabsContainer to controlled Tabs with useState
- Validating defaultTab against actual panel values
- Clearing stale parseErrors when template/data changes

packages/widgets/src/custom-api/jsx-interactive-components.tsx

@@ -69,9 +69,12 @@ function isTabPanel(child: ReactNode): child is React.ReactElement<TabPanelProps
 export function TabsContainer({ children, defaultTab }: TabsContainerProps) {
   const panels = Children.toArray(children).filter(isTabPanel);
   const firstPanel = panels[0];
+  const panelValues = new Set(panels.map((p) => p.props.value));
+  const initialTab = (defaultTab && panelValues.has(defaultTab) ? defaultTab : firstPanel?.props.value) ?? null;
+  const [activeTab, setActiveTab] = useState<string | null>(initialTab);
 
   return (
-    <Tabs defaultValue={defaultTab ?? firstPanel?.props.value}>
+    <Tabs value={activeTab} onChange={setActiveTab}>
       <Tabs.List>
         {panels.map((panel) => (
           <Tabs.Tab key={panel.props.value} value={panel.props.value}>