Revert "feat(config): implement loading and saving of bot node configuration with default notification settings"

This reverts commit ec1cf20347.

main.go

@@ -47,13 +47,6 @@ func main() {
 		log.Fatalf("Failed to load bot user config: %v", err)
 	}
 
-	// Load the node registry config. Unlike the other files it is optional:
-	// missing or empty bot_node_config.json simply means every node keeps its
-	// default enableStatusNotify (true).
-	if err := config.LoadBotNodeConfig(global.ConfigPath.BotNodeConfig); err != nil {
-		log.Fatalf("Failed to load bot node config: %v", err)
-	}
-
 	// Initialize logging.
 	postLog.SetDebugMode(cfg.System.DebugMode)
 	postLog.InitLogBroadcaster()