Fix delay timing buttons checked state in GUI sync

- Add proper setChecked(True/False) calls for delay timing buttons
- Ensure correct timing button shows as selected when loading preset
- Clear previous timing button selection before setting new one
- Fix timing button styling to properly reflect enabled/disabled and selected states

Now delay timing buttons should correctly show which timing is selected on startup.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

gui/arpeggiator_controls.py

@@ -1260,23 +1260,25 @@ class ArpeggiatorControls(QWidget):
             
             # Update delay timing buttons
             if hasattr(self, 'delay_timing_buttons') and hasattr(self.arpeggiator, 'delay_timing'):
-                # Clear current delay timing styling
+                # Clear current delay timing - uncheck old button
                 if hasattr(self, 'current_delay_timing') and self.current_delay_timing in self.delay_timing_buttons:
-                    self.apply_button_style(self.delay_timing_buttons[self.current_delay_timing], 10, "disabled")
+                    self.delay_timing_buttons[self.current_delay_timing].setChecked(False)
+                
                 # Set new active delay timing
                 self.current_delay_timing = self.arpeggiator.delay_timing
                 if self.current_delay_timing in self.delay_timing_buttons:
-                    if self.delay_enabled:
-                        self.apply_button_style(self.delay_timing_buttons[self.current_delay_timing], 10, "purple")
-                        # Enable and style all timing buttons
-                        for btn in self.delay_timing_buttons.values():
+                    # Check the correct timing button
+                    self.delay_timing_buttons[self.current_delay_timing].setChecked(True)
+                    
+                    # Style all timing buttons based on delay enabled state
+                    for timing, btn in self.delay_timing_buttons.items():
+                        if self.delay_enabled:
                             btn.setEnabled(True)
-                            if not btn.isChecked():
+                            if timing == self.current_delay_timing:
+                                self.apply_button_style(btn, 10, "purple")
+                            else:
                                 self.apply_button_style(btn, 10, "normal")
-                    else:
-                        self.apply_button_style(self.delay_timing_buttons[self.current_delay_timing], 10, "disabled")
-                        # Disable all timing buttons
-                        for btn in self.delay_timing_buttons.values():
+                        else:
                             btn.setEnabled(False)
                             self.apply_button_style(btn, 10, "disabled")