refactor: migrate to model provider abstraction and update dependencies}
* Remove bin/architect.js entry point script * Remove legacy MCP implementation from src/mcp.mjs * Refactor Anthropic provider with improved error handling and model configuration * Refactor OpenAI provider with updated API integration and parameter handling * Update package.json dependencies to latest versions * Expand README.md with comprehensive documentation and usage examples * Update change-log.md with detailed migration notes and breaking changes