refactor(socket): decouple command handling and add message sending

- Move command handler to variable for better flexibility
- Add SendMsg function for sending messages through socket
- Fix missing return statements in command execution
- Improve error handling in monitor exception reporting

main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"Watchdog_Linux-systemd/command"
 	"Watchdog_Linux-systemd/postLog"
 	"Watchdog_Linux-systemd/socket"
 	"fmt"
@@ -44,6 +45,10 @@ func main() {
 	}
 	postLog.Info(fmt.Sprintf("%s %s (Build %d.%s) by %s", softwareInfo.Name, softwareInfo.Version, softwareInfo.BuildVer, softwareInfo.BuildType, softwareInfo.Developer))
 
+	// Set command handler
+	socket.CommandHandler = command.ExecuteCommand
+	// End of command handler
+
 	go func() {
 		err := socket.BootSocket(Type, listenAddr, listenPort)
 		if err != nil {