Added a build step that generates the Pagefind index after astro build
Added @pagefind/default-ui and implemented the search UI
Added search routes at /search and /{lang}/search
Updated the header search icon to navigate to the current locale search page
Added a pagefind option to Layout for page-level index inclusion control
Excluded list-style pages from indexing (blog index, changelog index, ADR index/year/month pages, tools index, and search pages)
Notes
Search uses language-specific indexes based on html lang, so /en/search targets English pages while /search (default locale) mainly targets Japanese pages.