Add canonical term policy and normalize terminology

[XucroYuri]

Summary

• add a canonical term policy, term register, and repository checker for banned drift terms
• wire the new policy into README/governance surfaces and rename the voice reference pack
• normalize high-risk Chinese public surfaces to the new canonical terminology

Verification

• python3 scripts/check_canonical_terms.py
• python3 scripts/check_links.py
• python3 scripts/check_semantic_consistency.py
• python3 scripts/generate_index.py >/tmp/how-to-make-script-index.json && echo INDEX_OK
• python3 -m py_compile scripts/*.py
• python3 -m unittest discover -s tests -v