astro-corelisted

# Astro Core Shared model for the `astro` cluster. The rendering and content decisions below shape every page; keep them consistent. For full implementation, see `astro-framework`. ## 1. Rendering mode (decide first) | Need | Mode | |---|---| | Content known at build time (marketing, docs, blog) | **Static (SSG)** — the default; fastest, cheapest | | Per-request data (auth, personalization, form POST) | **On-demand (SSR)** — set `export const prerender = false` on that route | | Mostly static with a few dynamic fragments | **Static page + server islands** (`server:defer`) — render the shell statically, stream the dynamic piece | | Mixed across the site | **Hybrid** — static by default, opt specific routes into SSR | **Ship static by default; opt into SSR only where required.** Server islands keep a page static while deferring a dynamic fragment — prefer them over making the whole route SSR. ## 2. Islands & hydration Astro ships zero JS by default. A framework component is static HTML unless you add a directive: - `client:load` — hydrate immediately (above-the-fold interactivity). - `client:idle` — when the browser is idle (non-urgent). - `client:visible` — when scrolled into view (best default for below-the-fold). - `client:media` — when a media query matches. - `client:only` — skip SSR, render only on the client (for client-only libs). Keep islands small and hydrate at the **latest** directive that works. ## 3. Content (Content Layer & collections) - **Content coll