ci: prerender against the internal mesh API + fail loud if empty

The fedora-44 runner reaches the public internet (the CV gist on
api.github.com prerendered fine) but not the public rob.tn — split-horizon
DNS — so every moments-API-sourced route baked empty loading states while the
build still "succeeded". prefetchQuery swallows fetch errors, so the empty
snapshot shipped silently.

- Point VITE_API_BASE at the internal API the deploy already reaches
  (http://nikola.kosherinata.internal:42424/v1), verified reachable over the
  mesh. Only affects the SSR/prerender build; the browser bundle still uses the
  relative /api/v1.
- run-prerender.mjs now aborts (exit 1) if zero dynamic routes are enumerated,
  i.e. the API was unreachable — so an empty snapshot can never deploy again.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01X7zF7Kf4JqDwa6M8Qgge9M

ui/run-prerender.mjs

@@ -81,6 +81,22 @@ function outPathFor(route) {
 const template = await readFile(join(distDir, 'index.html'), 'utf8');
 let routes = await collectRoutes();
 
+// Guard: the dynamic routes (blog posts, projects) are enumerated from the
+// moments API. If none came back, the API was unreachable at build time — fail
+// loudly rather than bake and deploy an empty, content-free snapshot. (The CV,
+// sourced from the public GitHub gist, can still succeed independently.)
+const dynamicRouteCount = routes.filter(
+  (r) => r.startsWith('/project/') || r.startsWith('/blog/'),
+).length;
+if (dynamicRouteCount === 0) {
+  console.error(
+    'prerender: 0 dynamic routes enumerated — the moments API was unreachable ' +
+      'at build time. Aborting so an empty snapshot is never deployed. ' +
+      `(VITE_API_BASE=${process.env.VITE_API_BASE ?? '(unset)'})`,
+  );
+  process.exit(1);
+}
+
 // Optional filter args: `node run-prerender.mjs /activity /cv` bakes only the
 // routes whose path starts with one of the given prefixes (useful for quick
 // iteration). With no args, every route is baked.