Replace task/batch shorthand IDs and residual layer labels in
human-facing docs with semantic phrases. Add the new cleanup
policy to docs/编号规范.md and update the entry docs.
Machine keys (TC/CODE-RULE/MENU-STATE/TRAP/FR), hardware
designators/pins/MAC, protocol/version numbers and frozen
historical evidence are intentionally kept.
Docs only; no code behavior change. Verified with
check_doc_links.py --all and git diff --check.