Add @clack/prompts with spinner functionality to progress module

[amondnet]

Summary

Add @clack/prompts package to enable interactive prompts and animated spinner functionality in the progress module.

Motivation

• Need spinner support for long-running operations
• Want interactive CLI prompts (text, select, confirm, etc.)
• Enhance user experience with visual feedback

Proposed Implementation

New Files

• src/progress/spinner.ts - Spinner wrapper around @clack/prompts
• src/progress/prompts.ts - Interactive prompt functions
• test/progress/spinner.test.ts - Spinner tests
• test/progress/prompts.test.ts - Prompts tests

Modified Files

• src/progress/index.ts - Export new functions/types
• src/index.ts - Re-export from main entry
• package.json - Add @clack/prompts dependency

Features

• createSpinner() - Start/stop/error methods for animated spinner
• promptText(), promptSelect(), promptConfirm() - Interactive prompts
• Maintains consistency with existing createProgressIndicator()
• Backward compatible

Tasks

• Add @clack/prompts to package.json
• Implement spinner.ts with createSpinner()
• Implement prompts.ts with prompt functions
• Write tests for spinner
• Write tests for prompts
• Update exports in progress/index.ts
• Update main src/index.ts
• Add documentation/JSDoc