fix: serve the website dist so Coolify answers GET /

Nixpacks built Vite but had no production start command, so Coolify returned Cannot GET /.

Co-authored-by: Cursor <cursoragent@cursor.com>

CLAUDE.md

@@ -336,6 +336,7 @@ Keep rules general, evidence-backed, and under 20 words. Never add secrets, pers
 - Bump `version` in `package.json` only (+ lockfile); the manifest derives it via `pkg.version`.
 - Style inline; Tailwind classes do nothing until PostCSS is wired.
 - Verify CHANGELOG entries against code, not commit subjects or handoff summaries.
+- Website Coolify deploys must `npm start` (`server.mjs`) or the Dockerfile; Vite preview is not production.
 
 ## Memory protocol