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>

docker-compose.demo.yml

@@ -1,6 +1,10 @@
-# Archipelago Demo Stack - Mock backend + Vue UI
-# Deploy via Portainer: Web editor → paste this, or deploy from repo
+# Archipelago Demo Stack - Mock backend + Vue UI + AIUI Chat
+# Deploy via Portainer: Web editor -> paste this, or deploy from repo
 # Access at http://localhost:4848 (or your host:4848)
+#
+# Required: Set ANTHROPIC_API_KEY for AI chat to work
+# In Portainer: Add as environment variable when deploying
+# Locally: ANTHROPIC_API_KEY=sk-ant-... docker compose -f docker-compose.demo.yml up --build
 
 services:
   neode-backend:
@@ -21,6 +25,8 @@ services:
     container_name: archy-demo-web
     ports:
       - "4848:80"
+    environment:
+      ANTHROPIC_API_KEY: ${ANTHROPIC_API_KEY:-}
     depends_on:
       - neode-backend
     restart: unless-stopped