feat: add MongoDB table view with inline editing support

- Add document/table view toggle to MongoDocBrowser
- Convert MongoDB documents to DataGrid format (union of all top-level keys)
- Add customSave prop to DataGrid for pluggable save backends
- MongoDB grid save converts dirty rows to mongoUpdateDocument calls
- Enable transaction-mode toolbar (commit/rollback) for customSave

src/i18n/locales/en.ts

@@ -667,6 +667,8 @@ export default {
     invalidJsonValue: "This cell is not a valid JSON value",
     duplicateField: "Duplicate field name: {field}",
     edit: "Edit",
+    documentView: "Document View",
+    tableView: "Table View",
   },
   history: {
     title: "History",

src/i18n/locales/zh-CN.ts

@@ -653,6 +653,8 @@ export default {
     invalidJsonValue: "当前单元格不是合法 JSON 值",
     duplicateField: "字段名重复：{field}",
     edit: "编辑",
+    documentView: "文档视图",
+    tableView: "表格视图",
   },
   history: {
     title: "历史",