Add cancel shutdown feature and enhance system control access methods in dashboard

Controllers/ResourceController.cs

@@ -227,6 +227,48 @@ namespace ResourceMonitorService.Controllers
                 return StatusCode(500, "Internal server error");
             }
         }
+
+        [HttpPost("cancel-shutdown")]
+        public ActionResult CancelShutdown()
+        {
+            try
+            {
+                // Execute the shutdown abort command
+                var processInfo = new ProcessStartInfo
+                {
+                    FileName = "shutdown",
+                    Arguments = "/a",
+                    UseShellExecute = false,
+                    CreateNoWindow = true,
+                    RedirectStandardOutput = true,
+                    RedirectStandardError = true
+                };
+
+                var process = Process.Start(processInfo);
+                process?.WaitForExit();
+
+                var exitCode = process?.ExitCode ?? -1;
+                
+                string message;
+                if (exitCode == 0)
+                {
+                    message = "Shutdown/restart canceled successfully";
+                    _logger.LogInformation("Shutdown/restart canceled by user");
+                }
+                else
+                {
+                    message = "No shutdown/restart was scheduled to cancel, or cancellation failed";
+                    _logger.LogInformation("Attempted to cancel shutdown but none was scheduled");
+                }
+
+                return Ok(new { message });
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(ex, "Error canceling shutdown command");
+                return StatusCode(500, "Internal server error");
+            }
+        }
     }
 
     public class SystemControlRequest