feat: order processing

feat: order commands result save/load

internal/error/generic.go

@@ -63,6 +63,8 @@ const (
 	ErrInputUpgradeParameterNotAllowed
 	ErrInputUpgradeShipsAlreadyUpToDate
 	ErrInputUpgradeTechLevelInsufficient
+	ErrInputQuitCommandFollowedByCommand
+	ErrInputUnrecognizedCommand
 )
 
 func GenericErrorText(code int) string {
@@ -159,6 +161,10 @@ func GenericErrorText(code int) string {
 		return "Insufficient planet production capacity"
 	case ErrInputUpgradeTechLevelInsufficient:
 		return "Insifficient Tech level for requested upgrade"
+	case ErrInputQuitCommandFollowedByCommand:
+		return "'Quit' must be the last order's command"
+	case ErrInputUnrecognizedCommand:
+		return "Unrecognized command"
 	case ErrSendShipHasNoDrives:
 		return "One or more ships are not equipped with hyperdrive and cannot be moved"
 	case ErrSendUnreachableDestination: