feat(tools): add Cosmosmith workflow rule

[devnomad-byte]

Summary

Adds a Cosmosmith workflow rule under the Tools category.

The new rule covers:

• AGENTS.md as the canonical project constitution
• task.md as the task ledger and verification evidence
• thin adapters for Claude Code, Cursor, Copilot, OpenCode, and Trae
• role handoffs across product, research, architecture, UI/UX, frontend, backend, QA, DevOps, and governance review
• Prompt / Context / Harness / Loop practice for multi-agent work

It also updates the Chinese and English Tools rule index pages and refreshes generated site facts so the rule count stays in sync.

Verification

• npm test
• npm run lint
• npm run docs:build