feat(events): Expand MessageEvent with reply capabilities and detailed docstrings
fix(loader): Ensure plugin path is correctly managed in sys.path
feat(star): Improve Star class documentation and lifecycle method descriptions
feat(testing): Add plugin metadata handling in MockContext and enhance PluginHarness
feat(hello): Refactor HelloPlugin to utilize new reply methods and structured capabilities
test(decorators): Add tests for input/output model support in provide_capability
test(events): Implement tests for reply_image and reply_chain methods in MessageEvent
test(http): Validate API registration with capability handler references and error handling
test(tests): Enhance tests for plugin harness and directory handling in dev commands
