feat(app): Workspace-Umbau Schritt 1 — gesture-handler/reanimated/webview + Root-Wrapper

Fundament fuer den zoombaren Desktop-Workspace:
- react-native-gesture-handler@2.14.1, react-native-reanimated@3.6.2,
  react-native-webview@13.6.4 (kompatibel mit RN 0.73.4 / Hermes / old-arch)
- babel.config.js: reanimated/plugin als letztes Plugin
- index.js: gesture-handler als allererster Import
- App.tsx: GestureHandlerRootView um den gesamten Baum

Hinweis: nach npm install einmalig `npm start --reset-cache` + nativer Rebuild
(gradlew clean), sonst brechen die reanimated-Worklets still.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

android/App.tsx

@@ -8,6 +8,7 @@
 import React, { useEffect } from 'react';
 import { AppState, AppStateStatus, PermissionsAndroid, Platform, StatusBar, StyleSheet } from 'react-native';
 import AsyncStorage from '@react-native-async-storage/async-storage';
+import { GestureHandlerRootView } from 'react-native-gesture-handler';
 import { NavigationContainer, DefaultTheme } from '@react-navigation/native';
 import { createBottomTabNavigator } from '@react-navigation/bottom-tabs';
 
@@ -132,7 +133,7 @@ const App: React.FC = () => {
   }, []);
 
   return (
-    <>
+    <GestureHandlerRootView style={styles.root}>
       <StatusBar barStyle="light-content" backgroundColor="#0D0D1A" />
       <NavigationContainer theme={DarkTheme}>
         <Tab.Navigator
@@ -180,13 +181,16 @@ const App: React.FC = () => {
           />
         </Tab.Navigator>
       </NavigationContainer>
-    </>
+    </GestureHandlerRootView>
   );
 };
 
 // --- Styles ---
 
 const styles = StyleSheet.create({
+  root: {
+    flex: 1,
+  },
   header: {
     backgroundColor: '#12122A',
     elevation: 0,