feat(push): support --target=staging for preview envs

cmd/grounds/commands/push/push.go

@@ -22,9 +22,18 @@ func NewPushCommand() *cobra.Command {
 func newPush() *cobra.Command {
 	var target string
 	cmd := &cobra.Command{
-		Use:   "push [--target=dev]",
+		Use:   "push [--target=dev|staging]",
 		Short: "Build via Gradle plugin and deploy to a target",
+		Long: `Build the current project with the grounds-push Gradle plugin and deploy it.
+
+Targets:
+  dev     — long-lived, lands in your personal namespace (user-<handle>).
+  staging — ephemeral preview env, fresh namespace per push, auto-deleted after 7 days.
+            Public URL pattern: <name>-pr<id>.dev.grnds.io.`,
 		RunE: func(cmd *cobra.Command, _ []string) error {
+			if target != "dev" && target != "staging" {
+				return fmt.Errorf("invalid --target %q: must be \"dev\" or \"staging\"", target)
+			}
 			cwd, err := os.Getwd()
 			if err != nil {
 				return err
@@ -38,7 +47,7 @@ func newPush() *cobra.Command {
 			return gradle.Run(ctx, wrapper, args, cmd.OutOrStdout(), cmd.ErrOrStderr(), 0)
 		},
 	}
-	cmd.Flags().StringVar(&target, "target", "dev", "deploy target: dev")
+	cmd.Flags().StringVar(&target, "target", "dev", "deploy target: dev (persistent personal ns) or staging (ephemeral preview env, 7d TTL)")
 	return cmd
 }
 

cmd/grounds/commands/push/push_test.go

@@ -0,0 +1,43 @@
+package push
+
+import (
+	"bytes"
+	"strings"
+	"testing"
+)
+
+// Validates the --target flag's allow-list before grounds-push gets
+// invoked. The Gradle plugin already rejects bogus targets but
+// surfacing the error here gives a faster fail-loud signal and a
+// cleaner CLI error.
+func TestPushRejectsInvalidTarget(t *testing.T) {
+	cmd := newPush()
+	cmd.SetArgs([]string{"--target=production"})
+	var stderr bytes.Buffer
+	cmd.SetErr(&stderr)
+	cmd.SetOut(&stderr)
+	cmd.SilenceUsage = true
+
+	err := cmd.Execute()
+	if err == nil {
+		t.Fatal("expected an error for invalid target, got nil")
+	}
+	if !strings.Contains(err.Error(), "invalid --target") {
+		t.Errorf("expected 'invalid --target' in error, got: %v", err)
+	}
+	if !strings.Contains(err.Error(), "dev") || !strings.Contains(err.Error(), "staging") {
+		t.Errorf("expected error to mention 'dev' and 'staging', got: %v", err)
+	}
+}
+
+// Default value should match the help text + Gradle plugin default.
+func TestPushDefaultTargetIsDev(t *testing.T) {
+	cmd := newPush()
+	flag := cmd.Flag("target")
+	if flag == nil {
+		t.Fatal("expected --target flag to exist")
+	}
+	if flag.DefValue != "dev" {
+		t.Errorf("expected default --target=dev, got %q", flag.DefValue)
+	}
+}