feat(cli): always print version header first, add --no-version flag

Previously the version banner only printed via PersistentPreRun, which
Cobra skips for --help and bare invocations. It now prints from main()
before Cobra parses anything, so it's the first line for every command.
Suppressible with --no-version; skipped for the version subcommand to
avoid duplicating its own output.

cmd/relspec/main.go

@@ -6,6 +6,7 @@ import (
 )
 
 func main() {
+	printVersionHeader(os.Args[1:])
 	if err := rootCmd.Execute(); err != nil {
 		fmt.Fprintln(os.Stderr, err)
 		os.Exit(1)

cmd/relspec/root.go

@@ -13,6 +13,7 @@ var (
 	version   = "dev"
 	buildDate = "unknown"
 	prisma7   bool
+	noVersion bool
 )
 
 func init() {
@@ -54,9 +55,6 @@ bidirectional conversion between various database schema formats.
 It reads database schemas from multiple sources (live databases, DBML,
 DCTX, DrawDB, etc.) and writes them to various formats (GORM, Bun,
 JSON, YAML, SQL, etc.).`,
-	PersistentPreRun: func(cmd *cobra.Command, args []string) {
-		fmt.Printf("RelSpec %s (built: %s)\n\n", version, buildDate)
-	},
 }
 
 func init() {
@@ -72,4 +70,22 @@ func init() {
 	rootCmd.AddCommand(versionCmd)
 	rootCmd.AddCommand(reportCmd)
 	rootCmd.PersistentFlags().BoolVar(&prisma7, "prisma7", false, "Use Prisma 7 generator conventions when reading/writing Prisma schemas")
+	rootCmd.PersistentFlags().BoolVar(&noVersion, "no-version", false, "Suppress the RelSpec version header")
+}
+
+// printVersionHeader prints the "RelSpec <version> (built: <date>)" banner
+// that precedes all command output. It is invoked from main() before cobra
+// parses/executes anything, so it runs even for --help and bare invocations.
+// It is skipped when --no-version is present, or when the version subcommand
+// is being run (which prints its own, more detailed output).
+func printVersionHeader(args []string) {
+	for _, a := range args {
+		if a == "--no-version" {
+			return
+		}
+	}
+	if len(args) > 0 && args[0] == "version" {
+		return
+	}
+	fmt.Printf("RelSpec %s (built: %s)\n\n", version, buildDate)
 }