fix: QR scanner crash — missing NSCameraUsageDescription in Info.plist

The app crashed immediately when tapping QR scan because the Info.plist
was missing the required NSCameraUsageDescription key. iOS kills the app
with EXC_BAD_INSTRUCTION when camera access is requested without it.

Also fixes:
- Flash toggle could SIGABRT if lockForConfiguration failed (try? + unconditional unlock)
- Camera setup now logs errors instead of silently failing

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

PayfritBeacon/Info.plist

@@ -22,6 +22,8 @@
 	<string>$(CURRENT_PROJECT_VERSION)</string>
 	<key>LSRequiresIPhoneOS</key>
 	<true/>
+	<key>NSCameraUsageDescription</key>
+	<string>Payfrit Beacon needs camera access to scan QR codes on beacon labels for provisioning.</string>
 	<key>NSBluetoothAlwaysUsageDescription</key>
 	<string>Payfrit Beacon needs Bluetooth to detect and configure nearby beacons.</string>
 	<key>NSBluetoothPeripheralUsageDescription</key>

PayfritBeacon/Views/QRScannerView.swift

@@ -241,17 +241,31 @@ final class CameraPreviewUIView: UIView {
     func setFlash(_ on: Bool) {
         guard let device = AVCaptureDevice.default(for: .video),
               device.hasTorch else { return }
-        try? device.lockForConfiguration()
+        do {
+            try device.lockForConfiguration()
             device.torchMode = on ? .on : .off
             device.unlockForConfiguration()
+        } catch {
+            NSLog("[QRScanner] Failed to set torch: \(error.localizedDescription)")
+        }
     }
 
     private func setupCamera() {
         let session = AVCaptureSession()
         session.sessionPreset = .high
 
-        guard let device = AVCaptureDevice.default(.builtInWideAngleCamera, for: .video, position: .back),
-              let input = try? AVCaptureDeviceInput(device: device) else { return }
+        guard let device = AVCaptureDevice.default(.builtInWideAngleCamera, for: .video, position: .back) else {
+            NSLog("[QRScanner] ERROR: No back camera available")
+            return
+        }
+
+        let input: AVCaptureDeviceInput
+        do {
+            input = try AVCaptureDeviceInput(device: device)
+        } catch {
+            NSLog("[QRScanner] ERROR: Failed to create camera input: \(error.localizedDescription)")
+            return
+        }
 
         if session.canAddInput(input) {
             session.addInput(input)