Add persistent focus node for keyboard listener and improve focus handling

lib/main.dart

@@ -308,6 +308,7 @@ class MainPageState extends State<MainPage> with WindowListener {
   final TextEditingController _intervalController = TextEditingController();
   final TextEditingController _soundController = TextEditingController();
   final TextEditingController _searchController = TextEditingController();
+  final FocusNode _keyboardListenerFocusNode = FocusNode(); // Add persistent focus node
 
   Note? previousNote;
   Note? _currentlyDisplayedNote;
@@ -359,6 +360,7 @@ class MainPageState extends State<MainPage> with WindowListener {
     _previousEntryController.dispose();
     _currentEntryController.dispose();
     _currentEntryFocusNode.dispose();
+    _keyboardListenerFocusNode.dispose(); // Dispose the keyboard listener focus node
     _scratchController.dispose();
     _intervalController.dispose();
     _soundController.dispose();
@@ -424,13 +426,16 @@ class MainPageState extends State<MainPage> with WindowListener {
         await windowManager.setSize(const Size(1600, 900));
         await windowManager.center();
 
-        // Now show and focus
+        // Show and focus immediately
         await windowManager.show();
-        await Future.delayed(const Duration(milliseconds: 100)); // Short delay
         await windowManager.focus();
 
-        // Set input focus
-        _currentEntryFocusNode.requestFocus();
+        // Set input focus with a post-frame callback to ensure it sticks
+        WidgetsBinding.instance.addPostFrameCallback((_) {
+          if (mounted) {
+            _currentEntryFocusNode.requestFocus();
+          }
+        });
 
         // Play notification sound
         await _playSound();
@@ -439,7 +444,11 @@ class MainPageState extends State<MainPage> with WindowListener {
       } else {
         // Already visible, just focus
         await windowManager.focus();
-        _currentEntryFocusNode.requestFocus();
+        WidgetsBinding.instance.addPostFrameCallback((_) {
+          if (mounted) {
+            _currentEntryFocusNode.requestFocus();
+          }
+        });
         debugPrint("Window already visible, just focused");
       }
 
@@ -1229,9 +1238,7 @@ class MainPageState extends State<MainPage> with WindowListener {
   Widget build(BuildContext context) {
     // Wrap Scaffold with RawKeyboardListener as workaround for Escape key
     return RawKeyboardListener(
-      focusNode:
-          FocusNode()
-            ..requestFocus(), // Request focus to ensure keyboard events are captured
+      focusNode: _keyboardListenerFocusNode, // Use persistent focus node
       onKey: (RawKeyEvent event) {
         if (event is RawKeyDownEvent) {
           // Handle Escape to close window
@@ -1240,8 +1247,7 @@ class MainPageState extends State<MainPage> with WindowListener {
               "Escape pressed inside MainPage (RawKeyboardListener - Workaround)",
             );
             // Call method directly since we are in the state
-            FocusManager.instance.primaryFocus
-                ?.unfocus(); // Keep unfocus attempt
+            FocusManager.instance.primaryFocus?.unfocus(); // Keep unfocus attempt
             onWindowClose();
           }
           // Handle Ctrl+F to open search