cb9797d0e8
- Simplify flows.zh-CN.md to an entry + quick reference, add "Quick Navigation" and in-depth reading links, original sections 6/7/9/10 are retained in the entry page with titles but changed to links.
- Add in-depth reading sub-document:
- docs/ai-playbook/flows/frontend.zh-CN.md
- docs/ai-playbook/flows/backpressure-chunking.zh-CN.md
- docs/ai-playbook/flows/resume.zh-CN.md
- docs/ai-playbook/flows/reconnect-consistency.zh-CN.md
- docs/ai-playbook/index.zh-CN.md add "Process (In-depth reading split)" index