feat: 收口文档桥接与 OnlyOffice/Sidebar 回归

- 为 documents.save/meta/content、blocks.patch 与 sidebar.dataset.list 补齐 Rust 协议映射、共享契约与桥接执行器

- 对齐 BlockNote、Mindmap、OnlyOffice 的保存/路由元信息，并补真实浏览器回归脚本与 OnlyOffice 部署基线

- 忽略 Rust 本地构建产物与 Harness 调试状态文件，避免临时产物进入仓库历史

infra/onlyoffice/docker-compose.yml

@@ -0,0 +1,20 @@
+version: "3.9"
+
+services:
+  onlyoffice-documentserver:
+    image: onlyoffice/documentserver:9.3.1
+    container_name: mnote-onlyoffice-documentserver
+    restart: unless-stopped
+    ports:
+      - "8082:80"
+    environment:
+      JWT_ENABLED: "true"
+      JWT_SECRET: "change-me-to-strong-secret"
+      JWT_HEADER: "Authorization"
+      JWT_IN_BODY: "true"
+      USE_UNAUTHORIZED_STORAGE: "true"
+    extra_hosts:
+      - "host.docker.internal:host-gateway"
+    volumes:
+      # 说明：只挂插件目录，不覆盖 DocumentServer 自带 web-apps，避免升级后静态资源被旧版本文件覆盖。
+      - ../../src/components/onlyoffice/onlyoffice-plugins:/var/www/onlyoffice/documentserver/sdkjs-plugins:ro