Initial commit: MOPC platform with Docker deployment setup

Full Next.js 15 platform with tRPC, Prisma, PostgreSQL, NextAuth.
Includes production Dockerfile (multi-stage, port 7600), docker-compose
with registry-based image pull, Gitea Actions CI workflow, nginx config
for portal.monaco-opc.com, deployment scripts, and DEPLOYMENT.md guide.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/app/loading.tsx

@@ -0,0 +1,12 @@
+import { Loader2 } from 'lucide-react'
+
+export default function Loading() {
+  return (
+    <div className="flex min-h-screen items-center justify-center">
+      <div className="flex flex-col items-center gap-4">
+        <Loader2 className="h-8 w-8 animate-spin text-primary" />
+        <p className="text-sm text-muted-foreground">Loading...</p>
+      </div>
+    </div>
+  )
+}