Challenge 2: Requesting the Permission from Compose — Solution

@Composable
fun NotificationPermissionSection() {
    val context = LocalContext.current
    var isGranted by remember {
        mutableStateOf(
            ContextCompat.checkSelfPermission(context, Manifest.permission.POST_NOTIFICATIONS)
                == PackageManager.PERMISSION_GRANTED
        )
    }

    val launcher = rememberLauncherForActivityResult(
        contract = ActivityResultContracts.RequestPermission()
    ) { granted ->
        isGranted = granted
    }

    if (isGranted) {
        Text("Notifications are enabled")
    } else {
        Button(onClick = {
            launcher.launch(Manifest.permission.POST_NOTIFICATIONS)
        }) {
            Text("Enable Notifications")
        }
    }
}

Notes:
- The initial isGranted value is computed ONCE, at first composition,
  using ContextCompat.checkSelfPermission — this correctly reflects
  whatever the permission state already was (e.g. if granted in a
  previous session, the Button never even needs to show).
- launcher.launch(...) triggers the actual system permission dialog;
  the composable itself doesn't control what that dialog looks like or
  when it dismisses — only what happens with the resulting Boolean via
  the lambda passed to rememberLauncherForActivityResult.
- isGranted is a remembered mutableStateOf (Course 2, Chapter 1
  pattern), so updating it inside the launcher's callback automatically
  triggers recomposition — the UI switches from the Button to the
  "enabled" text the moment the user grants the permission, with no
  manual refresh needed.