Added simple daemonization option to the run command.

main.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"log"
 	"os"
+	"os/exec"
 	"os/signal"
 	"sync"
 	"syscall"
@@ -29,6 +30,19 @@ func main() {
 
 	switch command {
 	case "run":
+		// Check for daemon flag
+		isDaemon := false
+		for _, arg := range os.Args {
+			if arg == "--daemon" {
+				isDaemon = true
+				break
+			}
+		}
+
+		if isDaemon {
+			startDaemon()
+			return
+		}
 		runEngine(cfg)
 
 	case "recover":
@@ -61,14 +75,45 @@ func main() {
 }
 
 func printUsage() {
-	fmt.Println("Usage: engine [command]")
+	fmt.Println("Usage: engine [command] [--daemon]")
 	fmt.Println("\nCommands:")
 	fmt.Println("  run       Start the WebSocket ingestor and processing engine")
+	fmt.Println("            Use --daemon to run in background and log to engine.log")
 	fmt.Println("  recover   Run startup recovery to migrate stale ticks")
 	fmt.Println("  maintain  Run a single maintenance cycle (cleanup/retention)")
 	fmt.Println("  help      Show this help message")
 }
 
+func startDaemon() {
+	// Prepare arguments for the child process (remove --daemon)
+	args := []string{}
+	for _, arg := range os.Args[1:] {
+		if arg != "--daemon" {
+			args = append(args, arg)
+		}
+	}
+
+	// Prepare the command
+	cmd := exec.Command(os.Args[0], args...)
+	
+	// Open log file for output redirection
+	logFile, err := os.OpenFile("engine.log", os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666)
+	if err != nil {
+		log.Fatalf("Failed to open log file: %v", err)
+	}
+
+	cmd.Stdout = logFile
+	cmd.Stderr = logFile
+
+	// Start the process
+	if err := cmd.Start(); err != nil {
+		log.Fatalf("Failed to start daemon: %v", err)
+	}
+
+	fmt.Printf("Engine started in background (PID: %d). Logs: engine.log\n", cmd.Process.Pid)
+	os.Exit(0)
+}
+
 func runEngine(cfg Config) {
 	log.Println("=== Bybit BTC/USDT Tick Ingest Engine ===")
 	log.Printf("Config: symbol=%s, hot_retention=%dh, feature_retention=%dd",