Initial Flutter-Projekt-Setup (AP0)

Grundgerüst für die Emergency-App: Flutter-Projekt für Android/iOS,
Kern-Packages (url_launcher, geolocator, geocoding, permission_handler,
provider, shared_preferences, intl), Ordnerstruktur laut docs/plan.md
und l10n-Grundgerüst.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

android/.gitignore

@@ -0,0 +1,14 @@
+gradle-wrapper.jar
+/.gradle
+/captures/
+/gradlew
+/gradlew.bat
+/local.properties
+GeneratedPluginRegistrant.java
+.cxx/
+
+# Remember to never publicly share your keystore.
+# See https://flutter.dev/to/reference-keystore
+key.properties
+**/*.keystore
+**/*.jks