feat: demo deployment with AIUI chat, SSH key auth, Quick Start fix

- Add AIUI pre-built dist to demo/ for Portainer deployment
- Add nginx-demo.conf with Claude API proxy (envsubst for API key)
- Add docker-entrypoint.sh for runtime API key injection
- Update Dockerfile.web to include AIUI and Claude proxy
- Update docker-compose.demo.yml with ANTHROPIC_API_KEY env var
- Switch deploy script from sshpass to SSH key auth
- Fix Quick Start Goals animating before other cards (stagger 5, opacity guard)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

neode-ui/docker/docker-entrypoint.sh

@@ -0,0 +1,4 @@
+#!/bin/sh
+# Substitute only ANTHROPIC_API_KEY in nginx config, leave nginx variables untouched
+envsubst '${ANTHROPIC_API_KEY}' < /etc/nginx/nginx.conf.template > /etc/nginx/nginx.conf
+exec nginx -g 'daemon off;'