Fix Blank CRM Page

My customer-facing CRM suddenly stopped rendering—every route now shows a completely blank page. The stack is:

• Frontend: Vite-built JavaScript app, served by nginx
• Backend: Node.js + TypeScript with Fastify, Prisma, and a PostgreSQL database

Everything was working earlier, so I suspect a recent build, deploy, or dependency change has introduced a breaking issue. I haven’t been able to capture any obvious errors in the browser console or the server logs, and I’m not sure where to start.

Here’s what I need from you:

1. Diagnose why the frontend renders a blank screen and trace the problem through to the backend if necessary.
2. Apply (or guide me through applying) the fix—whether that involves Vite build settings, Fastify routes, Prisma queries, or nginx configuration—until the CRM loads normally again.
3. Provide a short report that outlines:
• The root cause
• Exact code or config changes made
• Preventive steps I can follow for future deployments

You’ll get Git repo access and SSH into the Ubuntu box where nginx proxies to the Fastify server. The Postgres data must remain intact, so please keep migrations or schema edits off the table unless we discuss them first.

If you’ve untangled Vite, Fastify, or nginx blank-screen bugs before, I’d like to get this resolved quickly—ideally today.