fix: Fix lambda function argument errors in overlay_window.py

BUG: TypeError: missing 1 required positional argument: 'checked'

The lambda functions were expecting a 'checked' argument that wasn't
being passed by the signals:
- QShortcut.activated doesn't pass any arguments
- SidebarButton.clicked doesn't pass any arguments

Fix: Removed 'checked' parameter from both lambda functions.

core/overlay_window.py

@@ -528,7 +528,7 @@ class OverlayWindow(QMainWindow):
         # Ctrl+1-9 to switch plugins
         for i in range(1, 10):
             shortcut = QShortcut(QKeySequence(f"Ctrl+{i}"), self)
-            shortcut.activated.connect(lambda checked, idx=i-1: self._switch_to_plugin(idx))
+            shortcut.activated.connect(lambda idx=i-1: self._switch_to_plugin(idx))
     
     def _setup_animations(self):
         """Setup window animations."""
@@ -559,7 +559,7 @@ class OverlayWindow(QMainWindow):
             
             # Create sidebar button
             btn = SidebarButton(plugin.name, icon_name, self.icon_manager)
-            btn.clicked.connect(lambda checked, i=idx: self._on_plugin_selected(i))
+            btn.clicked.connect(lambda i=idx: self._on_plugin_selected(i))
             
             # Insert before stretch
             self.sidebar_buttons_layout.insertWidget(idx, btn)