Description

This PR introduces a complete plugin system for the AgentForge framework, enabling extensibility and modular functionality. The plugin system allows developers to create, register, and use custom plugins that can add new tools, notification channels, and primitives to the framework without modifying core code.

Core Components Implemented

• Plugin Behavior: Defined a formal plugin behavior interface that plugins must implement
• Plugin Manager: Created a central registry for managing plugin lifecycle (loading, unloading, listing)
• Tools Registry: Implemented a registry for plugin-provided tools with dynamic discovery
• Notification System: Built a notification registry and channel system for plugins to hook into
• Plugin Integration: Added seamless integration with existing Flow and Signal systems

Technical Details

• Implemented the Plugin behavior with required callbacks (init, register_tools, metadata, etc.)
• Created the PluginManager GenServer to manage plugin state and registration
• Developed the Tools registry for function registration and discovery
• Built the Notification.Registry for managing communication channels
• Added HTTP plugin implementation as a reference plugin
• Created comprehensive testing infrastructure for plugins

Testing

The implementation includes extensive tests covering all aspects of the plugin system:

# Run plugin system tests
mix test test/agent_forge/plugin_system_test.exs

# Run the example tests
mix test test/agent_forge/examples_test.exs

# Run all tests
mix test

For more details, refer to this design doc.