Enhanced material design 3 implementation

lib/screens/admin/app_update_screen.dart

@@ -11,6 +11,7 @@ import 'package:flutter_quill/flutter_quill.dart' as quill;
 
 import '../../services/ai_service.dart';
 import '../../utils/snackbar.dart';
+import '../../widgets/app_page_header.dart';
 import '../../widgets/gemini_animated_text_field.dart';
 
 /// A simple admin-only web page allowing the upload of a new APK and the
@@ -478,13 +479,20 @@ class _AppUpdateScreenState extends ConsumerState<AppUpdateScreen> {
     }
 
     return Scaffold(
-      appBar: AppBar(title: const Text('APK Update Uploader')),
-      body: Center(
-        child: ConstrainedBox(
-          constraints: const BoxConstraints(maxWidth: 800),
-          child: Padding(
-            padding: const EdgeInsets.all(16.0),
-            child: Card(
+      body: Column(
+        crossAxisAlignment: CrossAxisAlignment.stretch,
+        children: [
+          const AppPageHeader(
+            title: 'App Update',
+            subtitle: 'Upload and manage APK releases',
+          ),
+          Expanded(
+            child: Center(
+              child: ConstrainedBox(
+                constraints: const BoxConstraints(maxWidth: 800),
+                child: Padding(
+                  padding: const EdgeInsets.fromLTRB(16, 0, 16, 16),
+                  child: Card(
               elevation: 2,
               shape: RoundedRectangleBorder(
                 borderRadius: BorderRadius.circular(12),
@@ -899,6 +907,9 @@ class _AppUpdateScreenState extends ConsumerState<AppUpdateScreen> {
           ),
         ),
       ),
-    );
+        ),
+      ],
+    ),
+  );
   }
 }