- get_myclaude_project_root() now expands ~ in MYCLAUDE_PROJECT_ROOT
(was resolving to ./~/path instead of $HOME/path)
- Extract hardcoded 16/8 depth limits as _MAX_WALK_DEPTH / _MAX_SOURCE_DEPTH
- Remove redundant cwd= from _run_pip_editable (already specified via -e)
- Add test_cwd_invalid_directory and test_env_var_expands_tilde
- Remove incorrect test_extra_args_forwarded (click.Group does not
support forwarding arbitrary args; ctx.args is always empty)