Refactor App layout and introduce new components for improved organization

- Replaced the main layout in App component with AppFrame for better structure.
- Introduced MainEditor component to encapsulate the main editing interface, including ProfileList and HistoryTable.
- Added ModelsTab component to manage model-related functionalities.
- Updated Sidebar to include a new Models tab for navigation.
- Removed unused components and streamlined the layout for enhanced user experience.

app/src/components/ModelsTab/ModelsTab.tsx

@@ -0,0 +1,9 @@
+import { ModelManagement } from '@/components/ServerSettings/ModelManagement';
+
+export function ModelsTab() {
+  return (
+    <div className="space-y-4 overflow-y-auto flex flex-col">
+      <ModelManagement />
+    </div>
+  );
+}