🐛 fix(query-editor): 优化事务下拉显示与浮层交互

- 自动提交延迟选项改为多语言完整文案，避免短标签语义不清
- 收窄并校准 V2 工具栏事务下拉宽度，兼顾不截断与紧凑布局
- 事务模式 Select 展开时自动隐藏 DBeaver 参考 Tooltip，避免浮层互相遮挡
- 补充事务设置行为测试和布局守护测试

frontend/src/components/QueryEditorTransactionSettings.test.tsx

@@ -0,0 +1,74 @@
+import React from 'react';
+import { act, create, type ReactTestRenderer } from 'react-test-renderer';
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest';
+
+import QueryEditorTransactionSettings from './QueryEditorTransactionSettings';
+
+const antdState = vi.hoisted(() => ({
+  selectProps: [] as any[],
+  tooltipProps: [] as any[],
+}));
+
+vi.mock('antd', () => ({
+  Select: (props: any) => {
+    antdState.selectProps.push(props);
+    return <button type="button">{props.value}</button>;
+  },
+  Tooltip: (props: any) => {
+    antdState.tooltipProps.push(props);
+    return <div>{props.children}</div>;
+  },
+}));
+
+vi.mock('../i18n/provider', () => ({
+  useOptionalI18n: () => ({
+    t: (key: string, params?: Record<string, unknown>) => params?.seconds ? `${params.seconds}s后提交` : key,
+  }),
+}));
+
+const latestSelectProps = () => antdState.selectProps[antdState.selectProps.length - 1];
+const latestTooltipProps = () => antdState.tooltipProps[antdState.tooltipProps.length - 1];
+
+describe('QueryEditorTransactionSettings', () => {
+  let renderer: ReactTestRenderer | null = null;
+
+  beforeEach(() => {
+    antdState.selectProps = [];
+    antdState.tooltipProps = [];
+  });
+
+  afterEach(() => {
+    renderer?.unmount();
+    renderer = null;
+  });
+
+  it('hides the DBeaver reference tooltip while the transaction mode select is open', () => {
+    act(() => {
+      renderer = create(
+        <QueryEditorTransactionSettings
+          isV2Ui
+          commitMode="manual"
+          autoCommitDelayMs={0}
+          onCommitModeChange={vi.fn()}
+          onAutoCommitDelayMsChange={vi.fn()}
+        />,
+      );
+    });
+
+    act(() => {
+      latestTooltipProps().onOpenChange(true);
+    });
+    expect(latestTooltipProps().open).toBe(true);
+
+    act(() => {
+      latestSelectProps().onOpenChange(true);
+    });
+    expect(latestTooltipProps().open).toBe(false);
+
+    act(() => {
+      latestSelectProps().onOpenChange(false);
+      latestTooltipProps().onOpenChange(true);
+    });
+    expect(latestTooltipProps().open).toBe(true);
+  });
+});