feat(chat-web): add Docker deployment for chat frontend

- Add @sveltejs/adapter-node for server-side rendering
- Create Dockerfile for chat web SvelteKit app
- Add /health endpoint for container health checks
- Add chat-web service to docker-compose.staging.yml
- Update CI/CD workflow with chat-web health check

The chat app now deploys with both backend and web frontend:
- mana-core-auth (port 3001) - central auth
- chat-backend (port 3002) - API
- chat-web (port 3000) - web frontend

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

docker-compose.staging.yml

@@ -1,4 +1,4 @@
-# Simplified staging config: mana-core-auth + chat-backend only
+# Simplified staging config: mana-core-auth + chat (backend + web)
 # Full config archived at: docker-compose.staging.full.yml
 #
 # To restore full config:
@@ -125,6 +125,34 @@ services:
         max-size: "10m"
         max-file: "3"
 
+  chat-web:
+    image: ${DOCKER_REGISTRY:-ghcr.io/memo-2023}/chat-web:${CHAT_WEB_VERSION:-latest}
+    container_name: chat-web-staging
+    restart: unless-stopped
+    depends_on:
+      chat-backend:
+        condition: service_healthy
+    environment:
+      NODE_ENV: staging
+      PORT: 3000
+      PUBLIC_BACKEND_URL: http://chat-backend:3002
+      PUBLIC_MANA_CORE_AUTH_URL: http://mana-core-auth:3001
+    ports:
+      - "3000:3000"
+    healthcheck:
+      test: ["CMD", "wget", "--no-verbose", "--tries=1", "--spider", "http://localhost:3000/health"]
+      interval: 30s
+      timeout: 10s
+      retries: 3
+      start_period: 40s
+    networks:
+      - manacore-network
+    logging:
+      driver: "json-file"
+      options:
+        max-size: "10m"
+        max-file: "3"
+
 # ============================================
 # Networks
 # ============================================