Yinyang collection maintenance

Read MODEL.md before maintaining this repository. It owns collection scope, independent member ownership, language, source limits, and publication boundaries. The root README editions introduce the actual collection members. Keep English and Chinese reader editions semantically aligned.

Each Skill under skills/ owns its complete package and supporting resources. For Yinyang, read its MODEL.md and its AGENTS.md before editing its philosophical account or formation method. Yinyang's references/docs/ and references/diagrams/ are package accessories, not root collections or independent Skills. Other actual Skills retain their specialist purpose and methods.

Keep changes within the affected owner. Verify local links and public source locators after relocation; preserve licenses, separate rights, third-party notices, executable modes, and assets. Do not invent demonstration members, copy a private portrait, or retrieve personal material just to maintain this public repository. Model-facing maintenance prose remains English.

Website implementation source is maintained privately in its native Site repository. This collection contains the canonical essays, diagrams and Skills, not a website source snapshot. Update reading projections through the Site's own publication route. Keep package downloads at GitHub and do not add a separate website package ZIP or Release/tag workflow.