feat: Add CLI self-update functionality with unified update management

[RoryDotGG]

Summary

This PR introduces CLI self-update functionality to synchronizer-cli, allowing users to update the CLI tool itself directly from the command line. It also implements automatic update checking and provides a unified update experience for both the CLI and Docker containers.

Key Changes

🆕 New Features

• CLI Self-Update: Users can now update synchronizer-cli without manually running npm/pnpm commands
• Automatic Update Checking: Performs daily background checks for CLI updates and notifies users when updates are available
• Unified Update Command: New synchronize update command checks for both CLI and container updates in one go

📝 Command Changes

• Added synchronize update - Check all updates (CLI + containers)
• Added synchronize update-cli - Check CLI updates only
• Renamed synchronize check-updates to synchronize update-container for consistency
• All commands now perform automatic update checks on launch

🔧 Technical Implementation

• Version comparison using semantic versioning
• Update check data persistence (checks once per day)
• Graceful error handling with helpful messages for permission issues
• Non-intrusive automatic checks (only shows notification if update available)

🎯 User Experience Improvements

• Interactive update process with confirmation prompts
• Clear visual feedback during update process
• Helpful error messages with fallback instructions
• Update summary showing all available updates
• Links to changelog for release notes

Example Usage

# Check for all updates
synchronize update

# Update CLI only
synchronize update-cli

# Update containers only
synchronize update-container

# Automatic check happens in background
synchronize start  # Will show update notification if available

Breaking Changes

• synchronize check-updates command renamed to synchronize update-container (old command will no longer work)

Testing

• CLI update check from npm registry
• Version comparison logic
• Automatic update notifications
• Interactive update process