docs: add Chinese translation style guide

[laughlife]

Summary

• Add a Simplified Chinese translation style guide for Clawland documentation.
• Define shared terminology for agents, fleet, skills, bounties, hardware docs, and API docs.
• Add a focused review checklist so Chinese documentation PRs can be checked consistently.

Context

This is a non-overlapping support slice for the Chinese Documentation Translation bounty. PR #1 already adds the core Chinese documentation pages, so this PR focuses on terminology consistency and reviewer guidance rather than duplicating those translated pages.

Validation

• npm run build

References #2