- Changed the kernel to a minimal Python REPL:
%%bashcells,%cd,%env, and!escapes were replaced bybash('cmd')andos.chdir(...)/os.environ[...](magic-style cells fail with a plain PythonSyntaxError); startup is faster and memory use is lower. - Removed the Jupyter/ipykernel kernel client; existing kernel venvs are rebuilt once (slimmer, no ipykernel) on next start.