fix: Ctrl+R flip also matches the physical R key (v1.6.1)

On some keymaps the R key resolves to a different logical key (observed on a
Turkish remote-desktop setup: the R key arrives as logical T), so the Ctrl+R
shortcut never fired even though the key events reached the app. The shortcut
now matches PhysicalKeyboardKey.keyR as well; a regression test covers the
wrong-layout case.

lib/shortcuts/app_shortcuts.dart

@@ -8,8 +8,14 @@ import '../services/file_handler.dart';
 class AppShortcuts extends StatelessWidget {
   final Widget child;
   final VoidCallback? onCropSave;
+  final VoidCallback? onFlipH;
 
-  const AppShortcuts({super.key, required this.child, this.onCropSave});
+  const AppShortcuts({
+    super.key,
+    required this.child,
+    this.onCropSave,
+    this.onFlipH,
+  });
 
   @override
   Widget build(BuildContext context) {
@@ -44,6 +50,17 @@ class AppShortcuts extends StatelessWidget {
             }
           }
 
+          // Ctrl+R: yatay aynala / geri al (fiziksel R: bazi klavye haritalarinda
+          // mantiksal tus T gibi farkli cozuluyor)
+          if (ctrl &&
+              (event.logicalKey == LogicalKeyboardKey.keyR ||
+                  event.physicalKey == PhysicalKeyboardKey.keyR)) {
+            if (onFlipH != null) {
+              onFlipH!();
+              return KeyEventResult.handled;
+            }
+          }
+
           switch (event.logicalKey) {
             case LogicalKeyboardKey.arrowLeft:
               ImageManager.instance.previousImage();