Add debug logging with Show Log button

- DebugLogger class saves logs to %TEMP%\CMM\debug.log
- Show Log button appears after 3s if loading takes too long
- Log viewer with Copy to Clipboard and Open Log File options
- Detailed logging throughout LoadMonitors for debugging

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

DellMonitorControl/MainWindow.xaml

@@ -215,6 +215,9 @@
                         </Ellipse>
                         <TextBlock Name="loadingText" Text="Loading..." Foreground="LightGray" FontSize="12"
                                    HorizontalAlignment="Center"/>
+                        <Button Name="showLogButton" Content="Show Log" Margin="0,10,0,0"
+                                Style="{StaticResource DarkButton}" FontSize="10"
+                                Click="ShowLogButton_Click" Visibility="Collapsed"/>
                     </StackPanel>
                 </StackPanel>
             </ScrollViewer>