Flutter-App mit WebView, STOMP-Client und Konfigurationssystem

- Flutter-App (app/) für iOS, Android, macOS, Windows und Linux erstellt
- WebView-Startseite mit flutter_inappwebview (iOS/Android/macOS/Windows),
  Linux-Fallback mit url_launcher
- STOMP-over-WebSocket: Topic-basierte Echtzeit-Kommunikation zwischen
  Flutter-App und Spring Boot Core
- Core: STOMP-Broker (/ws/stomp), CallEventBroadcaster auf /topic/calls,
  StompMessageController für /app/ping und /app/broadcast
- SecurityConfig: /ws/** permitAll + CSRF-Ausnahme
- Asset-basierte Konfigurationsdatei (app_config.json) für Server-URL,
  STOMP-Reconnect, Topics und WebView-URL
- launch.json um Flutter-Debug/Profile/Release-Konfigurationen erweitert
- macOS: FLTEnableMergedPlatformUIThread deaktiviert (WKWebView-Kompatibilität),
  network.client Entitlement gesetzt
- iOS: NSAllowsLocalNetworking für lokale Entwicklung
- Android: INTERNET-Permission und usesCleartextTraffic

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

app/.gitignore

@@ -0,0 +1,45 @@
+# Miscellaneous
+*.class
+*.log
+*.pyc
+*.swp
+.DS_Store
+.atom/
+.build/
+.buildlog/
+.history
+.svn/
+.swiftpm/
+migrate_working_dir/
+
+# IntelliJ related
+*.iml
+*.ipr
+*.iws
+.idea/
+
+# The .vscode folder contains launch configuration and tasks you configure in
+# VS Code which you may wish to be included in version control, so this line
+# is commented out by default.
+#.vscode/
+
+# Flutter/Dart/Pub related
+**/doc/api/
+**/ios/Flutter/.last_build_id
+.dart_tool/
+.flutter-plugins-dependencies
+.pub-cache/
+.pub/
+/build/
+/coverage/
+
+# Symbolication related
+app.*.symbols
+
+# Obfuscation related
+app.*.map.json
+
+# Android Studio will place build artifacts here
+/android/app/debug
+/android/app/profile
+/android/app/release