complete rewrite to grpc

main.go

@@ -169,10 +169,13 @@ func main() {
 		log.Fatalf("Error creating synced pool: %v\n", err)
 	}
 
-	hg, err := NewGrainHandler(app.pool, ":1337")
+	// Start unified gRPC server (CartActor + ControlPlane) replacing legacy RPC server on :1337
+	// TODO: Remove any remaining legacy RPC server references and deprecated frame-based code after full gRPC migration is validated.
+	grpcSrv, err := StartGRPCServer(":1337", app.pool, syncedPool)
 	if err != nil {
-		log.Fatalf("Error creating handler: %v\n", err)
+		log.Fatalf("Error starting gRPC server: %v\n", err)
 	}
+	defer grpcSrv.GracefulStop()
 
 	go func() {
 		for range time.Tick(time.Minute * 10) {
@@ -202,17 +205,21 @@ func main() {
 	mux.HandleFunc("/debug/pprof/trace", pprof.Trace)
 	mux.Handle("/metrics", promhttp.Handler())
 	mux.HandleFunc("/healthz", func(w http.ResponseWriter, r *http.Request) {
-		if !hg.IsHealthy() {
+		// Grain pool health: simple capacity check (mirrors previous GrainHandler.IsHealthy)
+		app.pool.mu.RLock()
+		grainCount := len(app.pool.grains)
+		capacity := app.pool.PoolSize
+		app.pool.mu.RUnlock()
+		if grainCount >= capacity {
 			w.WriteHeader(http.StatusInternalServerError)
-			w.Write([]byte("handler not healthy"))
+			w.Write([]byte("grain pool at capacity"))
 			return
 		}
 		if !syncedPool.IsHealthy() {
 			w.WriteHeader(http.StatusInternalServerError)
-			w.Write([]byte("pool not healthy"))
+			w.Write([]byte("control plane not healthy"))
 			return
 		}
-
 		w.WriteHeader(http.StatusOK)
 		w.Write([]byte("ok"))
 	})