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

rust/crates/core-protocol/src/command.rs

@@ -72,6 +72,25 @@ pub struct UpdatePageOptions {
     pub embed_default_block_id: Option<String>,
 }
 
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct SavePageContent {
+    pub page_id: String,
+    pub workspace_id: Option<String>,
+    pub revision: Option<u64>,
+    pub content_json: String,
+    pub conflict_detection_key: Option<String>,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct PatchPageBlock {
+    pub page_id: String,
+    pub block_id: String,
+    pub workspace_id: Option<String>,
+    pub revision: Option<u64>,
+    pub block_snapshot_json: String,
+    pub conflict_detection_key: Option<String>,
+}
+
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct InsertBlock {
     pub page_id: String,