🐛 fix(workbench): 修复结果区切换与对象设计字段定义

- 修复手动隐藏结果区后快捷键无法再次显示的问题

- 补全 Dameng/Oracle-like 字段长度、精度和可空标识

- 增加 SQL 编辑器、字段元数据和对象设计回归测试

frontend/src/components/QueryEditor.external-sql-save.test.tsx

@@ -741,6 +741,15 @@ describe('QueryEditor external SQL save', () => {
     });
     expect(textContent(renderer.toJSON())).not.toContain('等待执行 SQL');
 
+    const FakeNode = class {};
+    const bodyNode = new FakeNode();
+    const documentElement = new FakeNode();
+    vi.stubGlobal('Node', FakeNode);
+    vi.stubGlobal('document', {
+      body: bodyNode,
+      documentElement,
+    });
+    editorState.hasTextFocus = false;
     const isMacRuntime = /(Mac|iPhone|iPad|iPod)/i.test(`${navigator.platform || ''} ${navigator.userAgent || ''}`);
     const toggleEvent = {
       ctrlKey: !isMacRuntime,
@@ -748,7 +757,7 @@ describe('QueryEditor external SQL save', () => {
       altKey: false,
       shiftKey: true,
       key: 'm',
-      target: null,
+      target: bodyNode,
       preventDefault: vi.fn(),
       stopPropagation: vi.fn(),
     };