Add a practical guide to when LabNote fits

[Wonderforge-Lab]

Phase 5: the human doorway

Adds a concise README section and a deeper guide in English and Simplified Chinese.

It covers:

• the everyday problems that lead people to seek project continuity;
• where LabNote fits and where a simpler or different tool is better;
• natural prompts a person can give an AI to investigate options; and
• concrete criteria an AI can use when comparing public GitHub candidates.

The guidance is deliberately bounded: it does not call LabNote automatic memory, a personality store, an observability system or a replacement for one-shot work.