Refactor MainActivity to use MainScreen with scaffold and navigation setup

app/src/main/java/de/jadehs/strassenschadenpro2/MainActivity.kt

@@ -36,20 +36,7 @@ class MainActivity : ComponentActivity() {
         enableEdgeToEdge()
         setContent {
             StrassenSchadenPro2Theme {
-                //var count = 0
-                var count by remember { mutableStateOf(0) }
-                Column(modifier = Modifier.fillMaxSize(),
-                    verticalArrangement = Arrangement.Center,
-                    horizontalAlignment = Alignment.CenterHorizontally) {
-                    Text(text= count.toString())
-                    Button(onClick = {
-                        count++
-                        Log.d("MainActivity", "Button clicked $count")
-
-                    }) {
-                        Text("Click me")
-                    }
-                }
+                MainScreen()
             }
         }
     }