[em3s]

Summary

The docs are moving to kakao.github.io/actionbase/ (#507), so the site has to work under base: '/actionbase/'. Astro doesn't prefix base onto root-relative URLs in Markdown, components, or redirect destinations. Built with the new SITE_URL, starlight-links-validator fails on every ](/...) link, and the favicon, directory cards, and stories/* redirects point outside the site.

This PR makes all of those follow base. Nothing changes on actionbase.io because base is still / there. The actual switch is the next step.

Part of #507

Changes

• Add plugins/remark-base-path.mjs to prefix base onto root-relative link/image/definition URLs and MDX href/src. It runs before starlight-links-validator, so validation sees the final URLs
• Prefix base onto redirects destinations
• Use import.meta.env.BASE_URL in DirectoryList, CategoryDirectoryList, and the favicon in Head.astro
• Move the 404 "Go home" link from the hero action into the body, because Starlight passes hero link through as-is

How to Test

cd website
SITE_URL=https://kakao.github.io/actionbase/ npm run build
grep -rhoE '(href|src)="/[^"]*"' --include=*.html dist | grep -v '="/actionbase/'   # no output
npm run build   # base '/', output unchanged
npm run lint && npm run format:check

AI Assistance

• This PR was written largely with AI assistance.
  • Tool / model: Claude Code (Claude Opus 5.5)

[em3s]

Optimistic