test: add comprehensive tests for Jupyter stderr support

- Test Jupyter environment detection (with/without IPython) - Test stderr printing in Jupyter and non-Jupyter environments - Test IPython display fallback when display fails - Test stderr capture and piping - Test stderr reader exception handling - Test empty line filtering and final buffer handling - Test process without stderr stream Achieves 100% code coverage for the new functionality.

Author: dgenio

src/mcp/client/stdio/__init__.py

@@ -60,7 +60,7 @@ def _is_jupyter_notebook() -> bool:
 fromIPythonimportget_ipython# type: ignore[import-not-found]
 
 ipython=get_ipython() # type: ignore[no-untyped-call]
-returnipythonisnotNoneandipython.__class__.__name__in ("ZMQInteractiveShell", "TerminalInteractiveShell")
+returnipythonisnotNoneandipython.__class__.__name__in ("ZMQInteractiveShell", "TerminalInteractiveShell")# type: ignore[union-attr]
 exceptImportError:
 returnFalse