🔧 Fix zero-downtime deployment issues

- Fix Dockerfile standalone build path from /app/.next/standalone/gitea/portfolio to /app/.next/standalone/app
- Fix nginx configuration by removing conflicting server blocks
- Consolidate health check and main proxy into single server block
- Ensure proper load balancing between portfolio-app-1 and portfolio-app-2

✅ Deployment now working successfully with:
- Application running on both instances (healthy)
- Database and Redis running (healthy)
- Nginx load balancer working
- Health endpoints accessible
- Main portfolio site accessible at http://localhost/

Dockerfile

@@ -55,7 +55,7 @@ RUN chown nextjs:nodejs .next
 
 # Automatically leverage output traces to reduce image size
 # https://nextjs.org/docs/advanced-features/output-file-tracing
-COPY --from=builder --chown=nextjs:nodejs /app/.next/standalone ./
+COPY --from=builder --chown=nextjs:nodejs /app/.next/standalone/app ./
 COPY --from=builder --chown=nextjs:nodejs /app/.next/static ./.next/static
 
 # Copy Prisma files