fix(ui): unify visual interaction styling

[mychiffonn]

Summary

• remove the trailing author comma from short publication author lists
• unify link underline, hover, visited, active, and pointer states
• center the timeline marker without z-index
• restrict animated card borders to clickable cards and remove duplicate hover rings

Validation

• pnpm format:check
• pnpm lint
• pnpm lint:styles
• pnpm astro check (0 errors; existing generated-file hints only)