docs: add operator console walkthrough

[X-PG13]

Summary

• add a copy-pasteable local operator console walkthrough
• distinguish safe preview/demo steps from real outbound publishing
• link the walkthrough from the English and Chinese README operator docs sections

Verification

• ./.venv-dev/bin/python -m unittest tests.test_docs_links -v
• git diff --check
• make check PYTHON=./.venv-dev/bin/python

Closes #149