feat: advance local-first conflict and search indexing

- 补齐本地 markdown 冲突处理与合并写回路径\n- 增加本地搜索索引路由、刷新与 browser smoke\n- 同步更新 current-priority checklist 的阶段进度

rust/crates/mnote-web/src/routes/documents.rs

@@ -1558,6 +1558,32 @@ mod tests {
             .expect("save response");
 
         assert_eq!(response.status(), StatusCode::CONFLICT);
+        let body = to_bytes(response.into_body(), usize::MAX)
+            .await
+            .expect("body");
+        let payload: Value = serde_json::from_slice(&body).expect("json");
+        assert_eq!(payload["code"], "local_markdown_external_change");
+        assert_eq!(
+            payload["details"]["conflict"]["documentId"].as_str(),
+            Some(document_id)
+        );
+        assert_eq!(
+            payload["details"]["conflict"]["rootUri"].as_str(),
+            Some(root_uri.as_str())
+        );
+        assert_eq!(
+            payload["details"]["conflict"]["editorBaseVersion"].as_str(),
+            Some(stale_file_version.as_str())
+        );
+        assert!(payload["details"]["conflict"]["currentDiskVersion"]
+            .as_str()
+            .unwrap_or("")
+            .starts_with("local-md:local-mdid:expected-file-version:"));
+        assert!(payload["details"]["conflict"]["suggestedActions"]
+            .as_array()
+            .unwrap()
+            .iter()
+            .any(|action| action.as_str() == Some("merge")));
         let markdown = std::fs::read_to_string(root.join("README.md")).expect("read md");
         assert!(markdown.contains("# External"));
         assert!(!markdown.contains("# Editor"));