wake lock implemented

app/lib/ui/app_shell.dart

@@ -1,5 +1,6 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
+import 'package:wakelock_plus/wakelock_plus.dart';
 
 import '../app_mode/app_mode_cubit.dart';
 import 'screens/fly/fly_screen.dart';
@@ -18,12 +19,26 @@ class AppShell extends StatelessWidget {
     final mode = context.select((AppModeCubit c) => c.state.mode);
     final screen = mode == AppMode.fly ? const FlyScreen() : const PlanScreen();
 
-    return Scaffold(
-      body: Stack(
-        children: [
-          Positioned.fill(child: screen),
-          const Align(alignment: Alignment.topCenter, child: TopModeBar()),
-        ],
+    return BlocListener<AppModeCubit, AppModeState>(
+      listenWhen: (previous, current) => previous.mode != current.mode,
+      listener: (context, state) {
+        // Nur FLAG_KEEP_SCREEN_ON, kein PowerManager.WakeLock (Doku 4.20
+        // deckt den Foreground-Service fuer Hintergrund-Telemetrie separat
+        // ab). Android-Empfehlung: an die Activity-Sichtbarkeit gebunden,
+        // keine Permission, kein manuelles Leak-Risiko.
+        if (state.mode == AppMode.fly) {
+          WakelockPlus.enable();
+        } else {
+          WakelockPlus.disable();
+        }
+      },
+      child: Scaffold(
+        body: Stack(
+          children: [
+            Positioned.fill(child: screen),
+            const Align(alignment: Alignment.topCenter, child: TopModeBar()),
+          ],
+        ),
       ),
     );
   }