Capture feedback (shutter sound + flash) and Paperless UX; v0.1.1

- Camera: system shutter sound (only when ringer isn't silenced) + brief
  white flash overlay on capture, for clear feedback even on silent.
- Settings: snackbar confirmation when saving.
- Export: explain why the Paperless upload button is disabled when unconfigured.
- Bump versionCode 2 / versionName 0.1.1.

Fixes #1, #2

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

app/src/main/java/eu/geyskens/pdfscan/ui/screens/CameraScreen.kt

@@ -1,12 +1,16 @@
 package eu.geyskens.pdfscan.ui.screens
 
 import android.Manifest
+import android.media.AudioManager
+import android.media.MediaActionSound
 import androidx.camera.core.CameraSelector
 import androidx.camera.core.ImageCapture
 import androidx.camera.core.ImageCaptureException
 import androidx.camera.core.Preview
 import androidx.camera.lifecycle.ProcessCameraProvider
 import androidx.camera.view.PreviewView
+import androidx.compose.animation.core.Animatable
+import androidx.compose.animation.core.tween
 import androidx.compose.foundation.background
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Box
@@ -31,6 +35,7 @@ import androidx.compose.material3.Text
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.collectAsState
 import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableIntStateOf
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
@@ -98,6 +103,22 @@ private fun CameraContent(vm: ScanViewModel, navController: androidx.navigation.
     }
     var capturing by remember { mutableStateOf(false) }
 
+    // Capture feedback: system shutter sound + a brief white flash over the preview,
+    // so there's clear confirmation even when the phone is on silent.
+    val shutterSound = remember { MediaActionSound().apply { load(MediaActionSound.SHUTTER_CLICK) } }
+    val audioManager = remember { ContextCompat.getSystemService(context, AudioManager::class.java) }
+    val flash = remember { Animatable(0f) }
+    var captureTick by remember { mutableIntStateOf(0) }
+    androidx.compose.runtime.LaunchedEffect(captureTick) {
+        if (captureTick > 0) {
+            flash.snapTo(0.75f)
+            flash.animateTo(0f, tween(320))
+        }
+    }
+    androidx.compose.runtime.DisposableEffect(Unit) {
+        onDispose { shutterSound.release() }
+    }
+
     val previewView = remember {
         PreviewView(context).apply { scaleType = PreviewView.ScaleType.FILL_CENTER }
     }
@@ -146,6 +167,11 @@ private fun CameraContent(vm: ScanViewModel, navController: androidx.navigation.
                 onClick = {
                     if (capturing) return@FilledIconButton
                     capturing = true
+                    // Flash always; play the shutter sound only when the ringer isn't silenced.
+                    if (audioManager?.ringerMode == AudioManager.RINGER_MODE_NORMAL) {
+                        shutterSound.play(MediaActionSound.SHUTTER_CLICK)
+                    }
+                    captureTick++
                     val file = File(vm.capturesDir(), "cap_${System.currentTimeMillis()}.jpg")
                     val options = ImageCapture.OutputFileOptions.Builder(file).build()
                     imageCapture.takePicture(
@@ -183,6 +209,11 @@ private fun CameraContent(vm: ScanViewModel, navController: androidx.navigation.
                 )
             }
         }
+
+        // Shutter flash overlay (drawn on top, fades out quickly).
+        if (flash.value > 0f) {
+            Box(Modifier.fillMaxSize().background(Color.White.copy(alpha = flash.value)))
+        }
     }
 
     androidx.compose.runtime.DisposableEffect(Unit) {

app/src/main/java/eu/geyskens/pdfscan/ui/screens/ExportScreen.kt

@@ -155,6 +155,11 @@ fun ExportScreen(vm: ScanViewModel, navController: NavController) {
             }
 
             if (!settings.paperlessUrl.isNotBlank() || !settings.hasToken) {
+                Text(
+                    "Configureer eerst Paperless (server-URL + token) in de instellingen om te kunnen uploaden.",
+                    style = androidx.compose.material3.MaterialTheme.typography.bodySmall,
+                    color = Color(0xFF9A9A9A),
+                )
                 OutlinedButton(
                     onClick = { navController.navigate(Routes.SETTINGS) },
                     modifier = Modifier.fillMaxWidth(),

app/src/main/java/eu/geyskens/pdfscan/ui/screens/SettingsScreen.kt

@@ -21,6 +21,8 @@ import androidx.compose.material3.IconButton
 import androidx.compose.material3.OutlinedButton
 import androidx.compose.material3.OutlinedTextField
 import androidx.compose.material3.Scaffold
+import androidx.compose.material3.SnackbarHost
+import androidx.compose.material3.SnackbarHostState
 import androidx.compose.material3.Text
 import androidx.compose.material3.TopAppBar
 import androidx.compose.runtime.Composable
@@ -51,8 +53,10 @@ fun SettingsScreen(vm: ScanViewModel, navController: NavController) {
     var token by remember { mutableStateOf(vm.currentToken().orEmpty()) }
     var testing by remember { mutableStateOf(false) }
     var testResult by remember { mutableStateOf<String?>(null) }
+    val snackbarHostState = remember { SnackbarHostState() }
 
     Scaffold(
+        snackbarHost = { SnackbarHost(snackbarHostState) },
         topBar = {
             TopAppBar(
                 title = { Text("Instellingen") },
@@ -116,7 +120,12 @@ fun SettingsScreen(vm: ScanViewModel, navController: NavController) {
                 ) { Text("Verbinding testen") }
 
                 Button(
-                    onClick = { scope.launch { vm.savePaperless(url, token) } },
+                    onClick = {
+                        scope.launch {
+                            vm.savePaperless(url, token)
+                            snackbarHostState.showSnackbar("Instellingen opgeslagen ✓")
+                        }
+                    },
                     modifier = Modifier.weight(1f),
                 ) { Text("Opslaan") }
             }