Add Pagefind indexing and browser search adapters behind a provider switch.
This lets prebuild generate either Stork or Pagefind search artifacts and lets the existing search UI run against Pagefind while preserving scoped filters, excerpts, and result metadata.
Align local version markers and GitHub Actions with Node 24, switch the default test entrypoint to the maintained Vitest runner, and replace pnpm-incompatible npm helpers in repo scripts.
This also removes the obsolete AVA plus esm path and excludes disabled test fixtures from generic Vitest discovery so CI reflects the supported test surface.