Logs result of SendInput and PostMessage calls (#23)

* Logs result of SendInput calls

Adds logging to track the number of input events successfully sent by SendInput.

This helps diagnose potential issues where not all input events are processed correctly. It logs an error if the number of sent events doesn't match the expected count and a trace if all events are successfully sent.

* Logs PostMessage results

Adds logging to record the success or failure of PostMessage calls.
Logs the last Win32 error when PostMessage fails, aiding in debugging.
Logs successful message posts for tracing purposes.

Author: magicxor

WinSyncScroll/ViewModels/MainViewModel.cs

@@ -343,7 +343,20 @@ private async Task RunMouseEventProcessingLoopAsync(
                     if (!_options.Value.IsLegacyModeEnabled)
                     {
                         LogSendInput(inputs);
-                        PInvoke.SendInput(inputs.AsSpan(), SizeOfInput);
+                        var sentCount = PInvoke.SendInput(inputs.AsSpan(), SizeOfInput);
+                        
+                        if (sentCount != inputs.Length)
+                        {
+                            var lastError = Marshal.GetLastWin32Error();
+                            _logger.LogError("SendInput failed: expected to send {ExpectedCount} events, but only {SentCount} were sent. Last Win32 error: {LastError}",
+                                inputs.Length,
+                                sentCount,
+                                lastError);
+                        }
+                        else
+                        {
+                            _logger.LogTrace("Successfully sent {SentCount} input events", sentCount);
+                        }
                     }
                     else
                     {
@@ -369,7 +382,20 @@ private async Task RunMouseEventProcessingLoopAsync(
                                 lParam,
                                 targetX,
                                 targetY);
-                            PInvoke.PostMessage(windowHandle, (uint)buffer.MouseMessageId, (nuint)buffer.MouseMessageData.mouseData, lParam);
+                            
+                            var result = PInvoke.PostMessage(windowHandle, (uint)buffer.MouseMessageId, (nuint)buffer.MouseMessageData.mouseData, lParam);
+                            
+                            if (!result)
+                            {
+                                var lastError = Marshal.GetLastWin32Error();
+                                _logger.LogError("PostMessage failed for window {WindowHandle}: Last Win32 error: {LastError}",
+                                    windowHandle,
+                                    lastError);
+                            }
+                            else
+                            {
+                                _logger.LogTrace("Successfully posted message to window {WindowHandle}", windowHandle);
+                            }
                         }
                     }
                 }