Fix crash: remove positioning guide image loading

app/src/main/java/com/mindmachine/mvp/MainActivity.kt

@@ -2,7 +2,6 @@ package com.mindmachine.mvp
 
 import android.app.Activity
 import android.content.pm.ActivityInfo
-import android.graphics.BitmapFactory
 import android.os.Bundle
 import android.view.WindowManager
 import androidx.activity.ComponentActivity
@@ -10,7 +9,6 @@ import androidx.activity.compose.BackHandler
 import androidx.activity.compose.setContent
 import androidx.activity.viewModels
 import androidx.compose.foundation.background
-import androidx.compose.foundation.Image
 import com.mindmachine.mvp.session.DurationSliderCard
 import com.mindmachine.mvp.session.SetupTimelineEditor
 import androidx.compose.foundation.clickable
@@ -77,7 +75,6 @@ import androidx.compose.runtime.withFrameNanos
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.graphics.Color
-import androidx.compose.ui.graphics.asImageBitmap
 import androidx.compose.ui.input.pointer.pointerInput
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.platform.LocalLifecycleOwner
@@ -831,7 +828,6 @@ fun SettingsScreen(vm: MainViewModel) {
 
 @Composable
 fun PositioningScreen() {
-    val context = LocalContext.current
     Column(
         Modifier
             .fillMaxSize()
@@ -842,24 +838,6 @@ fun PositioningScreen() {
     ) {
         Text("Positioning Guidance", style = MaterialTheme.typography.headlineSmall, color = MaterialTheme.colorScheme.onBackground)
 
-        // Guide image (from assets)
-        val guideBitmap = remember {
-            runCatching {
-                context.assets.open("positioning_guide.png").use { input ->
-                    android.graphics.BitmapFactory.decodeStream(input)
-                }
-            }.getOrNull()
-        }
-        if (guideBitmap != null) {
-            Image(
-                bitmap = guideBitmap.asImageBitmap(),
-                contentDescription = "Positioning guide",
-                modifier = Modifier
-                    .fillMaxWidth()
-                    .padding(vertical = 8.dp)
-            )
-        }
-
         Text("• Lie on your back in a safe, comfortable place.", color = MaterialTheme.colorScheme.onBackground)
         Text("• Rest the phone across the upper nose/forehead area so it stays stable.", color = MaterialTheme.colorScheme.onBackground)
         Text("• Keep your eyes closed during immersive visual sessions.", color = MaterialTheme.colorScheme.onBackground)