Feature: Undo / Clean Command - `universal-box clean <projectName>`

## Feature Request

**Is your feature request related to a problem you're trying to solve with Universal-Box? Please describe.**
When a user initializes a project using `universal-box init`, they might realize they selected the wrong template, used the wrong directory, or want to abort setup midway.
Currently, there’s no built-in way to easily undo or clean up previously scaffolded files — the user must manually delete the project folder.

**Describe the solution you'd like**
Introduce a new CLI command:
```
universal-box clean
```
This command would:
- Safely delete the generated project folder and all its contents.
- Optionally ask for confirmation before deletion (e.g., “Are you sure you want to remove this project?”).
- Support a --force flag to skip confirmation for automation workflows.

Example usage:
```
universal-box clean my-app
# or
universal-box clean my-app --force
```

**Describe alternatives you've considered**
- Manually deleting folders using file explorer or shell commands.
- Adding a cleanup flag within init (but that would mix creation and deletion logic).

**How would this feature improve Universal-Box?**
This feature adds convenience and improves developer productivity by giving users a quick way to roll back failed or incorrect scaffolds.
It also makes Universal-Box safer to experiment with — users can test multiple templates and clean up with a single command.

**Additional context**
NA