v1.8.23: fix Ctrl+V/C/X/A/Z for non-Latin keyboard layouts, add Entry undo/redo

- Global keycode-based handler for Ctrl shortcuts (works with Russian, Chinese, any layout)
- Tkinter maps <<Paste>> to <Control-v> by keysym which fails on non-Latin layouts
- New handler intercepts <Control-Key> at 'all' level, checks keycodes and generates correct virtual events
- Added Undo/Redo support for Entry widgets (tk.Entry has no built-in undo)
- Tab switch focus management: terminal releases focus when switching away

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

gui/widgets/entry_undo.py

@@ -18,7 +18,6 @@ def enable_undo(ctk_entry):
         if not history or history[-1] != val:
             history.append(val)
             redo_stack.clear()
-            # Cap history size
             if len(history) > 200:
                 del history[:100]
 
@@ -46,15 +45,6 @@ def enable_undo(ctk_entry):
             _recording[0] = True
         return "break"
 
-    def _on_ctrl_key(event):
-        """Route Ctrl+key by physical keycode (layout-independent)."""
-        if event.keycode == 90:  # Z
-            return _undo(event)
-        if event.keycode == 89:  # Y
-            return _redo(event)
-        return None
-
     entry.bind("<KeyRelease>", _snapshot, add="+")
     entry.bind("<Control-z>", _undo)
     entry.bind("<Control-y>", _redo)
-    entry.bind("<Control-Key>", _on_ctrl_key)