build: add reproducible release bundles

cmd/rvc/main.go

@@ -25,6 +25,9 @@ import (
 
 const defaultControlSocket = "/run/rvbox/server.sock"
 
+// buildVersion is set by scripts/release for published artifacts.
+var buildVersion = "dev"
+
 func main() {
 	if err := run(os.Args[1:], os.Stdout, os.Stderr); err != nil {
 		fmt.Fprintln(os.Stderr, "rvc:", err)
@@ -33,6 +36,10 @@ func main() {
 }
 
 func run(args []string, output, diagnostics io.Writer) error {
+	if len(args) == 1 && args[0] == "--version" {
+		_, err := fmt.Fprintln(output, buildVersion)
+		return err
+	}
 	if len(args) == 0 {
 		return errors.New("a command is required (stat or run)")
 	}