fix: add nixos-rebuild to PATH and fix CLI hanging after deploy failure

- Add nixos-rebuild to listener service PATH in NixOS module
- Fix CLI deploy command hanging after receiving final status by properly
  tracking lastResponse time and exiting when all hosts have responded

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

cmd/homelab-deploy/main.go

@@ -16,7 +16,7 @@ import (
 	"github.com/urfave/cli/v3"
 )
 
-const version = "0.1.3"
+const version = "0.1.4"
 
 func main() {
 	app := &cli.Command{