Add --version flag and display version on startup

.env

@@ -1 +0,0 @@
-DSN=root:Maal12345678@tcp(localhost:3306)/nalu

cmd/gormcol/main.go

@@ -16,11 +16,33 @@ import (
 	"gorm.io/gorm"
 )
 
+// version returns the current version from git tag and last modification date.
+func version() string {
+	tag := "dev"
+	if out, err := exec.Command("git", "describe", "--tags", "--abbrev=0").Output(); err == nil {
+		tag = strings.TrimSpace(string(out))
+	}
+
+	date := ""
+	if out, err := exec.Command("git", "log", "-1", "--format=%ci").Output(); err == nil {
+		date = strings.TrimSpace(string(out))
+		if len(date) >= 10 {
+			date = date[:10]
+		}
+	}
+
+	if date != "" {
+		return fmt.Sprintf("%s (%s)", tag, date)
+	}
+	return tag
+}
+
 // main is the entry point for the gormcol-gen CLI tool.
 // It parses flags, loads configuration from .env, connects to the database,
 // and generates GORM models with column descriptors.
 func main() {
 
+	versionFlag := flag.Bool("version", false, "display version information")
 	dsn := flag.String("dsn", "", "database DSN (e.g. user:pass@tcp(host:3306)/dbname)")
 	filter := flag.String("filter", "", "regex to match table names (triggers batch mode)")
 	all := flag.Bool("all", false, "generate all tables matching filter (shows confirmation)")
@@ -44,7 +66,15 @@ func main() {
 
 	flag.Parse()
 
-	// Get DSN from flag or environment variable.
+	// Display version on startup.
+	fmt.Printf("gormcol %s\n", version())
+
+	// Display version if requested.
+	if *versionFlag {
+		return
+	}
+
+	// Connect to the database.
 	dsnValue := *dsn
 	if dsnValue == "" {
 		dsnValue = os.Getenv("DSN")