- Updated `import_string` to evict conflicting cached top-level plugin packages, ensuring proper isolation of plugins with the same package names.
- Preserved the order of legacy handler declarations in `_iter_discoverable_names` to maintain expected behavior for legacy plugins.
- Added tests to verify the isolation of top-level packages and the preservation of handler declaration order.
- Improved module cleanup in tests to prevent conflicts between plugins.
- Added Peer class for managing peer-to-peer communication, including initialization, invocation, and cancellation of requests.
- Introduced Transport abstract base class with StdioTransport and WebSocketTransport implementations for message handling.
- Created Star class for error handling in event-driven architecture.
- Developed MemoryTransport for testing purposes, allowing in-memory communication between peers.
- Implemented unit tests for Peer functionality, protocol message parsing, and runtime integration with plugins.
- Established entry point tests to ensure package import and command-line interface functionality.
