✨ feat(ui): 完成新版 UI 全量改造

- 整体布局：按新版 UI 重构左侧导航、对象树、连接分组和右键菜单体系

- 数据视图：优化 DDL 侧栏、横向滚动、筛选输入、编辑入口和虚拟表格体验

- AI 面板：重构新版入口、输入区、模型选择、快捷键和悬浮布局

- 标签与快捷键：补齐 Tab 悬浮信息、复制交互和 Mac/Windows 快捷键配置

- 工程质量：新增 v2 主题样式、菜单组件、外观工具和回归测试覆盖

frontend/src/components/TabManager.hover.test.tsx

@@ -0,0 +1,111 @@
+import React from 'react';
+import { readFileSync } from 'node:fs';
+import { renderToStaticMarkup } from 'react-dom/server';
+import { describe, expect, it, vi } from 'vitest';
+
+import { resolveTabHoverOpen, TabHoverInfo, stopTabHoverDragPropagation } from './TabManager';
+import type { TabData } from '../types';
+
+describe('TabManager hover info', () => {
+  it('memoizes the tab workbench so parent-only modal state does not repaint open tabs', () => {
+    const source = readFileSync(new URL('./TabManager.tsx', import.meta.url), 'utf8');
+
+    expect(source).toContain('const TabManager: React.FC = React.memo(() => {');
+  });
+
+  it('renders full v2 tab hover context for table tabs', () => {
+    const tab: TabData = {
+      id: 'conn-1-main-users',
+      title: 'users',
+      type: 'table',
+      connectionId: 'conn-1',
+      dbName: 'main',
+      tableName: 'users',
+    };
+
+    const markup = renderToStaticMarkup(
+      <TabHoverInfo
+        tab={tab}
+        displayTitle="[开发240] 表概览"
+        connectionLabel="开发240"
+        hostSummary="192.168.1.240"
+      />,
+    );
+
+    expect(markup).toContain('data-tab-hover-info="true"');
+    expect(markup).toContain('[开发240] 表概览');
+    expect(markup).toContain('类型');
+    expect(markup).toContain('表数据');
+    expect(markup).toContain('连接');
+    expect(markup).toContain('开发240');
+    expect(markup).toContain('Host');
+    expect(markup).toContain('192.168.1.240');
+    expect(markup).toContain('数据库');
+    expect(markup).toContain('main');
+    expect(markup).toContain('对象');
+    expect(markup).toContain('users');
+  });
+
+  it('renders db identity for redis tabs without a database name', () => {
+    const tab: TabData = {
+      id: 'redis-keys-conn-1-db2',
+      title: 'db2',
+      type: 'redis-keys',
+      connectionId: 'conn-1',
+      redisDB: 2,
+    };
+
+    const markup = renderToStaticMarkup(
+      <TabHoverInfo
+        tab={tab}
+        displayTitle="[缓存 | 10.0.0.8] db2"
+        connectionLabel="缓存"
+        hostSummary="10.0.0.8"
+      />,
+    );
+
+    expect(markup).toContain('REDIS');
+    expect(markup).toContain('Redis Key');
+    expect(markup).toContain('未指定');
+    expect(markup).toContain('db2');
+  });
+
+  it('stops hover card pointer events from reaching tab drag listeners without blocking text selection', () => {
+    const event = {
+      preventDefault: vi.fn(),
+      stopPropagation: vi.fn(),
+    } as unknown as React.SyntheticEvent<HTMLElement>;
+
+    stopTabHoverDragPropagation(event);
+
+    expect(event.preventDefault).not.toHaveBeenCalled();
+    expect(event.stopPropagation).toHaveBeenCalledTimes(1);
+  });
+
+  it('keeps tab hover hidden while the tab context menu is open', () => {
+    expect(resolveTabHoverOpen(true, false)).toBe(true);
+    expect(resolveTabHoverOpen(true, true)).toBe(false);
+    expect(resolveTabHoverOpen(false, true)).toBe(false);
+  });
+
+  it('wires hover card tab-switch and drag-blocking handlers with selectable text styles', () => {
+    const source = readFileSync(new URL('./TabManager.tsx', import.meta.url), 'utf8');
+
+    expect(source).toContain('onPointerDown={stopTabHoverDragPropagation}');
+    expect(source).toContain('onPointerUp={stopTabHoverDragPropagation}');
+    expect(source).toContain('onPointerDownCapture={stopTabHoverDragPropagation}');
+    expect(source).toContain('onMouseDown={stopTabHoverDragPropagation}');
+    expect(source).toContain('onMouseUp={stopTabHoverDragPropagation}');
+    expect(source).toContain('onClick={stopTabHoverDragPropagation}');
+    expect(source).toContain('onClickCapture={stopTabHoverDragPropagation}');
+    expect(source).toContain('onTouchStart={stopTabHoverDragPropagation}');
+    expect(source).toContain('onTouchEnd={stopTabHoverDragPropagation}');
+    expect(source).toContain('setIsHoverInfoOpen(false);');
+    expect(source).toContain('setIsTabMenuOpen(true);');
+    expect(source).toContain('open={resolveTabHoverOpen(isHoverInfoOpen, isTabMenuOpen)}');
+    expect(source).toContain('onOpenChange={handleHoverInfoOpenChange}');
+    expect(source).toContain('onOpenChange={handleTabMenuOpenChange}');
+    expect(source).toMatch(/\.gn-v2-tab-hover-card \{[^}]*cursor: text;[^}]*user-select: text;/s);
+    expect(source).toMatch(/\.gn-v2-tab-hover-card \* \{[^}]*user-select: text;/s);
+  });
+});