chore: 将 Cloudflare Tunnel 设为可选服务

使用 Docker Compose profiles 功能，默认不启动 tunnel 服务
启用方式: docker compose --profile tunnel up -d

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

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

docker-compose.yml

@@ -31,6 +31,7 @@ services:
       start_period: 40s
 
   # Cloudflare Tunnel (可选)
+  # 启用方式: docker compose --profile tunnel up -d
   # 需要在 .env 中设置 TUNNEL_TOKEN
   tunnel:
     image: cloudflare/cloudflared:latest
@@ -41,3 +42,5 @@ services:
       - TUNNEL_TOKEN=${TUNNEL_TOKEN}
     depends_on:
       - droid2api
+    profiles:
+      - tunnel