Move starting the engine behind run cli argument.

main.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"fmt"
 	"log"
 	"os"
 	"os/signal"
@@ -12,46 +13,66 @@ import (
 
 func main() {
 	log.SetFlags(log.LstdFlags | log.Lmicroseconds)
-	log.Println("=== Bybit BTC/USDT Tick Ingest Engine ===")
 
 	// Load configuration
 	cfg, err := LoadConfig("config.json")
 	if err != nil {
 		log.Fatalf("Config error: %v", err)
 	}
-	log.Printf("Config: symbol=%s, hot_retention=%dh, feature_retention=%dd",
-		cfg.Symbol, cfg.HotRetentionHours, cfg.FeatureRetentionDays)
 
-    if len(os.Args) > 1 {
+	if len(os.Args) < 2 {
+		printUsage()
+		return
+	}
 
-        switch os.Args[1] {
+	command := os.Args[1]
+
+	switch command {
+	case "run":
+		runEngine(cfg)
 
 	case "recover":
+		log.Println("=== Starting Recovery Mode ===")
 		sm, err := NewStorageManager(cfg)
 		if err != nil {
 			log.Fatal(err)
 		}
-
 		if err := sm.StartupRecovery(); err != nil {
 			log.Fatal(err)
 		}
-
 		log.Println("Recovery completed.")
-            return
 
 	case "maintain":
+		log.Println("=== Starting Manual Maintenance ===")
 		sm, err := NewStorageManager(cfg)
 		if err != nil {
 			log.Fatal(err)
 		}
-
 		sm.RunHourlyMaintenance()
-
 		log.Println("Maintenance completed.")
-            return
-        }
-    }
 
+	case "help":
+		printUsage()
+
+	default:
+		log.Printf("Unknown command: %s", command)
+		printUsage()
+	}
+}
+
+func printUsage() {
+	fmt.Println("Usage: engine [command]")
+	fmt.Println("\nCommands:")
+	fmt.Println("  run       Start the WebSocket ingestor and processing engine")
+	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 runEngine(cfg Config) {
+	log.Println("=== Bybit BTC/USDT Tick Ingest Engine ===")
+	log.Printf("Config: symbol=%s, hot_retention=%dh, feature_retention=%dd",
+		cfg.Symbol, cfg.HotRetentionHours, cfg.FeatureRetentionDays)
 
 	// Initialize storage (creates dirs, databases, tables)
 	sm, err := NewStorageManager(cfg)