CTAO Science Portal: static Astro site with git-based CMS (Sveltia + Gitea)

Portal code only; editorial content lives in the ctao/content repo on the
demo machine's Gitea and is overlaid at build time (see README.md and
deploy/README.md). Live demo: https://astro.isl-dev.grid.cyfronet.pl

astro.config.mjs

@@ -0,0 +1,31 @@
+import { defineConfig } from 'astro/config';
+
+// Static output (zero runtime) — the whole point of the git-based approach.
+export default defineConfig({
+  output: 'static',
+  // Public origin — used to build absolute URLs (canonical, og:*, RSS,
+  // sitemap). Change when the portal moves to its production domain.
+  site: 'https://astro.isl-dev.grid.cyfronet.pl',
+  // URL contract, pinned explicitly (these are the defaults): changing either
+  // later rewrites every public URL. nginx serves /path/ via try_files $uri/.
+  trailingSlash: 'ignore',
+  build: { format: 'directory' },
+  // Lossless whitespace handling instead of the v7 default 'jsx', which drops
+  // line breaks around inline elements and silently glues words to links when
+  // a template line wraps before <a>. Templates render as written.
+  compressHTML: true,
+  // Built-in prefetch on every internal link (no per-link attributes needed).
+  // Default 'hover' strategy: near-instant navigation without the bandwidth
+  // cost of 'viewport' on a 24-card grid; auto-falls back to 'tap' on
+  // data-saver / slow connections (Astro handles that).
+  prefetch: { prefetchAll: true },
+  vite: {
+    build: {
+      // Lightning CSS (the default minifier) illegally folds animation-timeline
+      // INTO the `animation` shorthand (`animation: ... view()`), which browsers
+      // reject — silently killing every scroll-driven effect in production.
+      // esbuild minifies without property merging.
+      cssMinify: 'esbuild',
+    },
+  },
+});