Volume pages should have their own citation

As discussed under #8000 etc.

Right now the frontmatter (if it exists) has the citation.

Is this just a front-end change (in Hugo), or does it require any back-end changes?

Review the existing volume-page frontmatter and Hugo rendering to determine where citations are currently produced. Trace whether the citation data comes from the front end or requires a back-end change; done means each volume page displays its own citation without relying on frontmatter.

由索引模型根据 Issue 内容生成。