Release 2.1.0

Three new modules for plan T11, plus serve.js now taking its cache headers from the shared policy (its own headers are unchanged):

• openvibe-shared/cache-policy — isHashed(path), assetHeaders(path, { hashed }) (immutable for a content-addressed asset, otherwise public, max-age=300, stale-while-revalidate=86400), htmlHeaders({ private, maxAge, swr }) and an applyHtml() middleware, so "hashed asset = immutable, HTML = stale-while-revalidate" is one rule instead of one per site.
• openvibe-shared/indexnow — createIndexNow({ host, key, keyLocation?, endpoint?, fetch, log }) → keyFile, ping(urls) (one POST, deduped, https-only, own host, ≤10,000 URLs, never throws) and pingSoon(urls) (one debounced batch in 30 s). No key means no request.
• boost.js (OVBoost.start({ main }), served at /shared/boost.js) — smooth same-site page moves for a server-rendered site: a click fetches the next page (prefetched on hover, focus or touch), loads its new stylesheets first, swaps <main> in place with the shared transition, updates the title and the head tags that describe the page, runs the new main's inline scripts once, keeps history and scroll, and moves focus to the content. Any doubt (another release marker <meta name="ov-boost">, other external scripts, a non-HTML answer, a redirect off the site, an error) is a normal page load. Pages listen for ov:boost:load to wire their widgets.