camera: NSLog fallback in photo delegate so we can see it fired

User reports macOS photo still rotated AND no `photo:` line in
banlu.jsonl — so either the delegate isn't firing at all or the
event-channel path is broken on the success branch.

Add `NSLog` at the top of `photoOutput(_:didFinishProcessingPhoto:error:)`
and on the CGImage path. NSLog lands in `flutter run` stderr +
macOS Console regardless of channel state, so even if the diag
event drops we'll see the delegate firing + the CGImage's
dimensions. Once we see them we'll know whether it's a delegate
problem or a channel problem.

darwin/Camera/PhotoOutput.swift

@@ -1,6 +1,7 @@
 import AVFoundation
 import Foundation
 import ImageIO
+import os.log
 
 /// Wraps `AVCapturePhotoOutput`. One instance per
 /// [CameraInstance]; gets added to the session at create time and
@@ -111,6 +112,13 @@ private final class PhotoCaptureDelegate: NSObject, AVCapturePhotoCaptureDelegat
         didFinishProcessingPhoto photo: AVCapturePhoto,
         error: Error?
     ) {
+        // Belt-and-suspenders logging: the event-channel `diag` is the
+        // primary path (lands in `banlu.jsonl` via ux.Log), but NSLog
+        // is a fallback that ALWAYS lands in `flutter run` stderr +
+        // macOS Console regardless of channel state. Helps confirm
+        // whether the delegate is even firing when the jsonl shows
+        // nothing.
+        NSLog("[ux.camera] photoOutput callback fired error=\(error?.localizedDescription ?? "none")")
         if let error = error as NSError? {
             diag("photo capture failed: domain=\(error.domain)"
                  + " code=\(error.code) desc=\(error.localizedDescription)")
@@ -140,6 +148,7 @@ private final class PhotoCaptureDelegate: NSObject, AVCapturePhotoCaptureDelegat
             )))
             return
         }
+        NSLog("[ux.camera] cgImage: %dx%d", cgImage.width, cgImage.height)
         diag("photo: \(cgImage.width)x\(cgImage.height) " +
              "(cgImageRepresentation, no EXIF)")
         let destination = CGImageDestinationCreateWithURL(