Pagefind site search adoption policy

Decision

• Adopt Pagefind as the site-wide search engine.
• Provide search routes at /search and /{lang}/search, using language-specific indexes based on html[lang].
• Make Pagefind indexing mandatory after astro build in the build pipeline.
• Route header search navigation to the current locale search page.

Context

The site is fully static and needs full-text search without introducing server-side search infrastructure. The site already serves multilingual URLs (ja/en/ko/fr/de/pt), so search behavior should stay language-scoped.

Options

• Option A: Use an external hosted search service.
• Option B: Build and maintain a custom search API.
• Option C: Introduce Pagefind with static indexing (chosen).

Rationale

• Pagefind runs after static HTML generation and fits the Astro workflow.
• Language-aware index selection via html[lang] is available out of the box.
• Client-side search keeps operational overhead low and avoids extra infrastructure dependencies.

Consequences

• Production builds must generate dist/pagefind/.
• Initial UI implementation uses @pagefind/default-ui, with room to move to a custom UI later.
• Further relevance tuning (exclude selectors, weighting, metadata enrichment) will be added after observing real search usage.