refactor: Projektstruktur in app/ und backend/ aufgeteilt

app/lib/services/developer.dart

@@ -0,0 +1,47 @@
+// Wrapper around dart:developer.log that also outputs logs in release mode.
+//
+// Usage: import this file as `developer` instead of `dart:developer`.
+// Then call `developer.log(...)` as usual. In debug/profile, it forwards to
+// dart:developer.log; in release it prints to stdout so logs are visible.
+export 'dart:developer' hide log;
+
+import 'dart:async' show Zone;
+import 'dart:developer' as dev;
+import 'package:flutter/foundation.dart';
+
+void log(
+  String message, {
+  DateTime? time,
+  int? sequenceNumber,
+  int level = 0,
+  String name = '',
+  Zone? zone,
+  Object? error,
+  StackTrace? stackTrace,
+}) {
+  if (kReleaseMode) {
+    final ts = (time ?? DateTime.now()).toIso8601String();
+    final tag = name.isNotEmpty ? '[$name] ' : '';
+    final seq = sequenceNumber != null ? ' #$sequenceNumber' : '';
+    final lvl = level != 0 ? ' L$level' : '';
+    final err = error != null ? ' | error: $error' : '';
+    final st = stackTrace != null ? ' | stack: $stackTrace' : '';
+    // Keep it a single line to avoid mixing with platform loggers.
+    // Using print to ensure output in release builds.
+    // Example: 2025-09-13T12:47:00.123Z [StompService] Connected ... L800 #42
+    // Note: Some platforms may trim long lines; we still prefer a single print.
+    // ignore: avoid_print
+    print('$ts $tag$message$seq$lvl$err$st');
+  } else {
+    dev.log(
+      message,
+      time: time,
+      sequenceNumber: sequenceNumber,
+      level: level,
+      name: name,
+      zone: zone,
+      error: error,
+      stackTrace: stackTrace,
+    );
+  }
+}