feat(Greeter): Add install/uninstall/activate cli commands & new UI opts

- AppArmor profile management
- Introduced `dms greeter uninstall` command to remove DMS greeter configuration and restore previous display manager.
- Implemented AppArmor profile installation and uninstallation for enhanced security.

core/cmd/dms/assets/cli-policy.default.json

@@ -4,6 +4,7 @@
     "greeter install",
     "greeter enable",
     "greeter sync",
+    "greeter uninstall",
     "setup"
   ],
   "message": "This command is disabled on immutable/image-based systems. Use your distro-native workflow for system-level changes."