fix: ok tuşları + buton hover/siyah border + çift tıklama cover

lib/widgets/custom_title_bar.dart

@@ -41,22 +41,45 @@ class CustomTitleBar extends StatelessWidget {
   }
 }
 
-class _BarButton extends StatelessWidget {
+class _BarButton extends StatefulWidget {
   final IconData icon;
   final VoidCallback onTap;
 
   const _BarButton({required this.icon, required this.onTap});
 
+  @override
+  State<_BarButton> createState() => _BarButtonState();
+}
+
+class _BarButtonState extends State<_BarButton> {
+  bool _hovered = false;
+
   @override
   Widget build(BuildContext context) {
     return GestureDetector(
-      onTap: onTap,
+      onTap: widget.onTap,
       child: MouseRegion(
         cursor: SystemMouseCursors.click,
-        child: SizedBox(
+        onEnter: (_) => setState(() => _hovered = true),
+        onExit: (_) => setState(() => _hovered = false),
+        child: Container(
           width: 36,
           height: 28,
-          child: Icon(icon, color: Colors.white54, size: 16),
+          decoration: BoxDecoration(
+            border: Border.all(
+              color: Colors.black54,
+              width: 1,
+            ),
+            color: _hovered ? Colors.red.withValues(alpha: 0.7) : Colors.transparent,
+            borderRadius: const BorderRadius.only(
+              topRight: Radius.circular(4),
+            ),
+          ),
+          child: Icon(
+            widget.icon,
+            color: Colors.white,
+            size: 14,
+          ),
         ),
       ),
     );