Propagate camera binding errors to UI

Add an error StateFlow to CameraManager so camera binding failures
are surfaced to the user instead of silently swallowed by
e.printStackTrace(). CameraScreen collects this flow and displays
errors using the existing red overlay UI. Added Log.e with proper
TAG for logcat visibility.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/src/main/java/no/naiv/tiltshift/camera/CameraManager.kt

@@ -2,6 +2,7 @@ package no.naiv.tiltshift.camera
 
 import android.content.Context
 import android.graphics.SurfaceTexture
+import android.util.Log
 import android.util.Size
 import android.view.Surface
 import androidx.camera.core.Camera
@@ -24,6 +25,10 @@ import java.util.concurrent.Executor
  */
 class CameraManager(private val context: Context) {
 
+    companion object {
+        private const val TAG = "CameraManager"
+    }
+
     private var cameraProvider: ProcessCameraProvider? = null
     private var camera: Camera? = null
     private var preview: Preview? = null
@@ -32,6 +37,13 @@ class CameraManager(private val context: Context) {
 
     val lensController = LensController()
 
+    private val _error = MutableStateFlow<String?>(null)
+    val error: StateFlow<String?> = _error.asStateFlow()
+
+    fun clearError() {
+        _error.value = null
+    }
+
     private val _zoomRatio = MutableStateFlow(1.0f)
     val zoomRatio: StateFlow<Float> = _zoomRatio.asStateFlow()
 
@@ -117,8 +129,8 @@ class CameraManager(private val context: Context) {
             }
 
         } catch (e: Exception) {
-            // Camera binding failed
-            e.printStackTrace()
+            Log.e(TAG, "Camera binding failed", e)
+            _error.value = "Camera failed: ${e.message}"
         }
     }
 

app/src/main/java/no/naiv/tiltshift/ui/CameraScreen.kt

@@ -104,6 +104,17 @@ fun CameraScreen(
     val minZoom by cameraManager.minZoomRatio.collectAsState()
     val maxZoom by cameraManager.maxZoomRatio.collectAsState()
     val isFrontCamera by cameraManager.isFrontCamera.collectAsState()
+    val cameraError by cameraManager.error.collectAsState()
+
+    // Show camera errors via the existing error UI
+    LaunchedEffect(cameraError) {
+        cameraError?.let { message ->
+            showSaveError = message
+            cameraManager.clearError()
+            delay(2000)
+            showSaveError = null
+        }
+    }
 
     // Collect orientation updates
     LaunchedEffect(Unit) {