refactor: replace commander with native Node.js parseArgs

[MarshallOfSound]

Summary

Replaced the commander CLI framework dependency with Node.js's built-in parseArgs utility from the node:util module. This eliminates an external dependency while maintaining all existing CLI functionality.

Key Changes

• Removed commander dependency from package.json
• Replaced commander import with parseArgs from node:util
• Refactored CLI structure from fluent command builder pattern to a declarative commands object
• Implemented custom argument parsing and validation logic using parseArgs
• Added custom help text generation (printHelp() and printCommandHelp()) to replace commander's built-in help
• Converted command handlers to use positional arguments and parsed options
• Maintained all existing commands: pack, list, extract-file, extract, and integrity-digest
• Preserved command aliases and all option flags with their original behavior

Implementation Details

• Commands are now defined as a configuration object with metadata (aliases, usage, description, args, options, action)
• Manual argument parsing and validation replaces commander's automatic handling
• Help system is custom-built to match the original output format
• Error handling for missing required arguments and invalid commands is explicit
• All command actions properly handle both synchronous and asynchronous operations via Promise.resolve()

https://claude.ai/code/session_018MZgp8bWBzCGeFy3SaCjtC