feat: Implement immutable DMS command policy

- Added pre-run checks for greeter and setup commands to enforce policy restrictions
- Created cli-policy.default.json to define blocked commands and user messages for immutable environments.

core/cmd/dms/commands_setup.go

@@ -16,9 +16,10 @@ import (
 )
 
 var setupCmd = &cobra.Command{
-	Use:   "setup",
-	Short: "Deploy DMS configurations",
-	Long:  "Deploy compositor and terminal configurations with interactive prompts",
+	Use:               "setup",
+	Short:             "Deploy DMS configurations",
+	Long:              "Deploy compositor and terminal configurations with interactive prompts",
+	PersistentPreRunE: requireMutableSystemCommand,
 	Run: func(cmd *cobra.Command, args []string) {
 		if err := runSetup(); err != nil {
 			log.Fatalf("Error during setup: %v", err)