Refactor vpp.go to have the connection mgmt and vpp_*.go to have one Manager each

src/main.go

@@ -45,11 +45,19 @@ func main() {
 		log.Fatalf("Failed to start AgentX: %v", err)
 	}
 
-	// Set up interface event callback to update interface details
-	vpp.SetInterfaceEventCallback(interfaceMIB.UpdateInterfaceDetails)
+	// Create VPP client and managers
+	vppClient := vpp.NewVPPClient()
+	interfaceManager := vpp.NewInterfaceManager(vppClient)
+	statsManager := vpp.NewStatsManager(vppClient, interfaceManager)
 
-	// Start VPP stats routine with callback to update MIB
-	vpp.StartStatsRoutine(interfaceMIB.UpdateStats)
+	// Set up interface event callback to update interface details
+	interfaceManager.SetEventCallback(interfaceMIB.UpdateInterfaceDetails)
+
+	// Set up stats callback to update MIB
+	statsManager.SetStatsCallback(interfaceMIB.UpdateStats)
+
+	// Start VPP stats routine
+	statsManager.StartStatsRoutine()
 
 	// Set up signal handling for graceful shutdown
 	sigChan := make(chan os.Signal, 1)
@@ -59,6 +67,10 @@ func main() {
 	<-sigChan
 	logger.Printf("Shutting down...")
 
+	// Stop stats routine and disconnect
+	statsManager.StopStatsRoutine()
+	vppClient.Disconnect()
+
 	// Flush any buffered log entries
 	logger.Sync()
 }