Show debug-mode message for widget rebuilds in profile mode

When running in profile mode, the Performance panel showed a
disabled 'Count widget builds' checkbox which was misleading.
Widget rebuild counts rely on debugOnRebuildDirtyWidget which
is only available in debug mode.

This change:
- Removes the checkbox when running in profile mode
- Shows a clear message: 'Rebuild information is not available
  for this frame. Widget rebuild counts are only available when
  running an app in debug-mode.'
- Adds widget tests for both profile mode and debug mode behavior

Fixes #9730

Author: crackedhandle

packages/devtools_app/lib/src/screens/performance/panes/rebuild_stats/rebuild_stats.dart

@@ -92,6 +92,19 @@ class _RebuildStatsViewState extends State<RebuildStatsView>
 
   @override
   Widget build(BuildContext context) {
+    final isProfileBuild =
+        serviceConnection.serviceManager.connectedApp?.isProfileBuildNow ??
+        false;
+    if (isProfileBuild) {
+      return const Center(
+        child: Text(
+          'Rebuild information is not available for this frame.\n'
+          'Widget rebuild counts are only available when running '
+          'an app in debug-mode.',
+          textAlign: TextAlign.center,
+        ),
+      );
+    }
     return Column(
       crossAxisAlignment: CrossAxisAlignment.start,
       children: [

packages/devtools_app/test/screens/performance/rebuild_stats/rebuild_stats_view_test.dart

@@ -0,0 +1,93 @@
+// Copyright 2026 The Flutter Authors
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file or at https://developers.google.com/open-source/licenses/bsd.
+
+import 'dart:async';
+
+import 'package:devtools_app/devtools_app.dart';
+import 'package:devtools_app/src/screens/performance/panes/rebuild_stats/rebuild_stats.dart';
+import 'package:devtools_app/src/screens/performance/panes/rebuild_stats/rebuild_stats_model.dart';
+import 'package:devtools_app/src/screens/performance/panes/flutter_frames/flutter_frame_model.dart';
+import 'package:devtools_app_shared/service.dart';
+import 'package:devtools_app/devtools_app.dart';
+import 'package:devtools_app_shared/ui.dart';
+import 'package:devtools_app_shared/utils.dart';
+import 'package:devtools_test/devtools_test.dart';
+import 'package:devtools_test/helpers.dart';
+import 'package:flutter/foundation.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:mockito/mockito.dart';
+
+void main() {
+  group('RebuildStatsView', () {
+    late FakeServiceConnectionManager fakeServiceConnection;
+    late RebuildCountModel model;
+    late ValueNotifier<FlutterFrame?> selectedFrame;
+
+    setUp(() {
+      fakeServiceConnection = FakeServiceConnectionManager();
+      final app = fakeServiceConnection.serviceManager.connectedApp!;
+      when(app.initialized).thenReturn(Completer()..complete(true));
+      when(app.isDartWebAppNow).thenReturn(false);
+      when(app.isFlutterAppNow).thenReturn(true);
+      when(app.isDartCliAppNow).thenReturn(false);
+      when(app.isDartWebApp).thenAnswer((_) async => false);
+      when(app.isProfileBuild).thenAnswer((_) async => false);
+      setGlobal(ServiceConnectionManager, fakeServiceConnection);
+      setGlobal(IdeTheme, IdeTheme());
+      setGlobal(NotificationService, NotificationService());
+      setGlobal(BannerMessagesController, BannerMessagesController());
+      setGlobal(PreferencesController, PreferencesController());
+      setGlobal(OfflineDataController, OfflineDataController());
+      model = RebuildCountModel();
+      selectedFrame = ValueNotifier<FlutterFrame?>(null);
+    });
+
+    testWidgets(
+      'shows message when running in profile mode',
+      (WidgetTester tester) async {
+        final app = fakeServiceConnection.serviceManager.connectedApp!;
+        when(app.isProfileBuildNow).thenReturn(true);
+
+        await tester.pumpWidget(
+          wrapWithControllers(
+            RebuildStatsView(
+              model: model,
+              selectedFrame: selectedFrame,
+            ),
+          ),
+        );
+        await tester.pump();
+
+        expect(
+          find.textContaining('Widget rebuild counts are only available'),
+          findsOneWidget,
+        );
+      },
+    );
+
+    testWidgets(
+      'shows normal UI when running in debug mode',
+      (WidgetTester tester) async {
+        final app = fakeServiceConnection.serviceManager.connectedApp!;
+        when(app.isProfileBuildNow).thenReturn(false);
+
+        await tester.pumpWidget(
+          wrapWithControllers(
+            RebuildStatsView(
+              model: model,
+              selectedFrame: selectedFrame,
+            ),
+          ),
+        );
+        await tester.pump();
+
+        expect(
+          find.textContaining('Widget rebuild counts are only available'),
+          findsNothing,
+        );
+      },
+    );
+  });
+}