feat: add club selection clearing button and improve navigation logic after login

mobile-app/composeApp/src/androidMain/kotlin/de/tsschulz/tt_tagebuch/app/ui/AppRoot.kt

@@ -5937,6 +5937,21 @@ private fun SettingsScreen(
         ) {
             Text(tr("auth.logout", "Abmelden"))
         }
+
+        OutlinedButton(
+            onClick = {
+                dependencies.applicationScope.launch {
+                    // Clear only the club selection so the ClubSelectScreen appears
+                    dependencies.clubManager.clearSelection()
+                }
+            },
+            modifier = Modifier
+                .fillMaxWidth()
+                .padding(top = 8.dp)
+                .heightIn(min = TouchMinHeight),
+        ) {
+            Text(tr("club.change", "Verein wechseln"))
+        }
     }
 }
 

mobile-app/composeApp/src/commonMain/kotlin/de/tsschulz/tt_tagebuch/app/ui/LoginScreen.kt

@@ -71,7 +71,14 @@ class LoginScreen : Screen {
             
             LaunchedEffect(state) {
                 if (state is LoginState.Success) {
-                    navigator?.push(HomeScreen(1)) // Using clubId 1 for now
+                    // Login succeeded. Do not hardcode navigation to a specific club here;
+                    // the platform-specific host (e.g. AppRoot) decides the next screen.
+                    // Try to pop this screen if there is a previous entry.
+                    try {
+                        navigator?.pop()
+                    } catch (_: Exception) {
+                        // ignore
+                    }
                 }
             }
         }