Fix nullability warnings and improve process selection logic in CPU usage retrieval

Worker.cs

@@ -126,7 +126,7 @@ namespace ResourceMonitorService
                     var requestBody = await new StreamReader(context.Request.Body).ReadToEndAsync();
                     var parameters = JsonConvert.DeserializeObject<dynamic>(requestBody);
 
-                    string action = parameters?.Action?.ToString()?.ToLower(); // "shutdown" or "restart"
+                    string? action = parameters?.Action?.ToString()?.ToLower(); // "shutdown" or "restart"
                     int delaySeconds = parameters?.DelaySeconds ?? 0;
 
                     // Validate action input
@@ -248,32 +248,32 @@ namespace ResourceMonitorService
                         }
                     })
                     .Where(p => p != null)
-                    .OrderByDescending(p => p.TotalProcessorTime)
+                    .OrderByDescending(p => p!.TotalProcessorTime)
-                    .Select(p => p.Process)
+                    .Select(p => p!.Process)
                     .ToList();
 
                 // Create a new anonymous type containing the CPU usage, RAM usage, and the top 3 highest CPU-using processes
                 return new
                 {
                     Usage = usage,
-                    Process1 = new
+                    Process1 = processes.Count > 0 ? new
                     {
-                        Name = processes.ElementAt(0).ProcessName,
+                        Name = processes[0].ProcessName,
-                        TotalProcessorTime = processes.ElementAt(0).TotalProcessorTime,
+                        TotalProcessorTime = processes[0].TotalProcessorTime,
-                        WorkingSet64 = processes.ElementAt(0).WorkingSet64 / (1024 * 1024) // Convert to MB
+                        WorkingSet64 = processes[0].WorkingSet64 / (1024 * 1024) // Convert to MB
-                    },
+                    } : null,
-                    Process2 = new
+                    Process2 = processes.Count > 1 ? new
                     {
-                        Name = processes.ElementAt(1).ProcessName,
+                        Name = processes[1].ProcessName,
-                        TotalProcessorTime = processes.ElementAt(1).TotalProcessorTime,
+                        TotalProcessorTime = processes[1].TotalProcessorTime,
-                        WorkingSet64 = processes.ElementAt(1).WorkingSet64 / (1024 * 1024) // Convert to MB
+                        WorkingSet64 = processes[1].WorkingSet64 / (1024 * 1024) // Convert to MB
-                    },
+                    } : null,
-                    Process3 = new
+                    Process3 = processes.Count > 2 ? new
                     {
-                        Name = processes.ElementAt(2).ProcessName,
+                        Name = processes[2].ProcessName,
-                        TotalProcessorTime = processes.ElementAt(2).TotalProcessorTime,
+                        TotalProcessorTime = processes[2].TotalProcessorTime,
-                        WorkingSet64 = processes.ElementAt(2).WorkingSet64 / (1024 * 1024) // Convert to MB
+                        WorkingSet64 = processes[2].WorkingSet64 / (1024 * 1024) // Convert to MB
-                    }
+                    } : null
                 };
             }