Add command-line configuration management tools

[wesen]

Adds a new config command group for managing go-go-mcp configuration files and profiles
through the command line:

Key features:

• Create and edit configuration files with init and edit commands
• Manage profiles with add-profile, duplicate-profile, and set-default-profile
• Add tool sources with add-tool --dir and add-tool --file
• List and inspect profiles with list-profiles and show-profile
• Preserves comments and formatting when editing configuration files

Technical changes:

• YAML editor package for manipulating YAML while preserving structure
• Config editor type for managing go-go-mcp specific configuration
• Path helpers for handling default and custom config locations
• Updated documentation with CLI configuration workflow examples

The changes make it easier to create and maintain configuration files through a
consistent CLI interface rather than manual editing.