💄 style(query-editor): 调整 v2 查询工具栏布局样式

- 为查询工具栏控件增加 v2 专用 class，移除 v2 下 inline 固定宽度依赖

- 使用内容宽度约束选择区，避免最大行数后出现多余空白

- 覆盖 Ant Design Button.Group 负 margin 和伪元素合并效果

- 增加 CSS 静态断言覆盖对齐、间距和响应式布局

frontend/src/components/QueryEditor.tsx

@@ -4875,92 +4875,105 @@ const QueryEditor: React.FC<{ tab: TabData; isActive?: boolean }> = ({ tab, isAc
       `}</style>
       <div ref={editorPaneRef} className={isV2Ui ? 'gn-v2-query-editor-pane' : undefined}>
       <div className={isV2Ui ? 'gn-v2-query-toolbar' : undefined} style={{ padding: '4px 8px 8px', display: 'flex', gap: '8px', flexShrink: 0, alignItems: 'center' }}>
-        <Select 
-            style={{ width: 150 }} 
-            placeholder="选择连接"
-            value={currentConnectionId}
-            onChange={(val) => {
-                setCurrentConnectionId(val);
-                setCurrentDb('');
-            }}
-            options={queryCapableConnections.map(c => ({ label: c.name, value: c.id }))}
-            showSearch
-        />
-        <Select 
-            style={{ width: 200 }} 
-            placeholder="选择数据库"
-            value={currentDb}
-            onChange={setCurrentDb}
-            options={dbList.map(db => ({ label: db, value: db }))}
-            showSearch
-        />
-        <Tooltip title="最大返回行数（会对 SELECT 自动加 LIMIT，防止大结果集卡死）">
-            <Select
-                style={{ width: 170 }}
-                value={queryOptions?.maxRows ?? 5000}
-                onChange={(val) => setQueryOptions({ maxRows: Number(val) })}
-                options={[
-                    { label: '最大行数：500', value: 500 },
-                    { label: '最大行数：1000', value: 1000 },
-                    { label: '最大行数：5000', value: 5000 },
-                    { label: '最大行数：20000', value: 20000 },
-                    { label: '最大行数：不限', value: 0 },
-                ]}
-            />
-        </Tooltip>
-        <Button.Group>
-          <Tooltip
-              title={
-	                  runQueryShortcutBinding.enabled && runQueryShortcutBinding.combo
-	                      ? `运行（${getShortcutDisplayLabel(runQueryShortcutBinding.combo, activeShortcutPlatform)}）`
-	                      : '运行'
-              }
-          >
-              <Button type="primary" icon={<PlayCircleOutlined />} onMouseDown={captureEditorCursorPosition} onClick={handleRun} loading={loading}>
-                运行
-              </Button>
+        <div
+          className={isV2Ui ? 'gn-v2-query-toolbar-selects' : undefined}
+          style={{ display: 'flex', gap: '8px', flexShrink: 0, alignItems: 'center' }}
+        >
+          <Select
+              className={isV2Ui ? 'gn-v2-query-toolbar-select gn-v2-query-toolbar-connection-select' : undefined}
+              style={isV2Ui ? undefined : { width: 150 }}
+              placeholder="选择连接"
+              value={currentConnectionId}
+              onChange={(val) => {
+                  setCurrentConnectionId(val);
+                  setCurrentDb('');
+              }}
+              options={queryCapableConnections.map(c => ({ label: c.name, value: c.id }))}
+              showSearch
+          />
+          <Select
+              className={isV2Ui ? 'gn-v2-query-toolbar-select gn-v2-query-toolbar-database-select' : undefined}
+              style={isV2Ui ? undefined : { width: 200 }}
+              placeholder="选择数据库"
+              value={currentDb}
+              onChange={setCurrentDb}
+              options={dbList.map(db => ({ label: db, value: db }))}
+              showSearch
+          />
+          <Tooltip title="最大返回行数（会对 SELECT 自动加 LIMIT，防止大结果集卡死）">
+              <Select
+                  className={isV2Ui ? 'gn-v2-query-toolbar-select gn-v2-query-toolbar-max-rows-select' : undefined}
+                  style={isV2Ui ? undefined : { width: 170 }}
+                  value={queryOptions?.maxRows ?? 5000}
+                  onChange={(val) => setQueryOptions({ maxRows: Number(val) })}
+                  options={[
+                      { label: '最大行数：500', value: 500 },
+                      { label: '最大行数：1000', value: 1000 },
+                      { label: '最大行数：5000', value: 5000 },
+                      { label: '最大行数：20000', value: 20000 },
+                      { label: '最大行数：不限', value: 0 },
+                  ]}
+              />
           </Tooltip>
-          {loading && (
-            <Button type="primary" danger icon={<StopOutlined />} onClick={handleCancel}>
-              停止
-            </Button>
-          )}
-        </Button.Group>
-        <Button.Group>
+        </div>
+        <div
+          className={isV2Ui ? 'gn-v2-query-toolbar-actions' : undefined}
+          style={{ display: 'flex', gap: '8px', flexShrink: 0, alignItems: 'center' }}
+        >
+          <Button.Group className={isV2Ui ? 'gn-v2-query-toolbar-action-group' : undefined}>
             <Tooltip
                 title={
-                    saveQueryShortcutBinding.enabled && saveQueryShortcutBinding.combo
-                        ? `保存（${getShortcutDisplayLabel(saveQueryShortcutBinding.combo, activeShortcutPlatform)}）`
-                        : '保存'
+	                    runQueryShortcutBinding.enabled && runQueryShortcutBinding.combo
+	                        ? `运行（${getShortcutDisplayLabel(runQueryShortcutBinding.combo, activeShortcutPlatform)}）`
+	                        : '运行'
                 }
             >
-              <Button icon={<SaveOutlined />} onClick={handleQuickSave}>
-                保存
+                <Button className={isV2Ui ? 'gn-v2-query-toolbar-run-action' : undefined} type="primary" icon={<PlayCircleOutlined />} onMouseDown={captureEditorCursorPosition} onClick={handleRun} loading={loading}>
+                  运行
+                </Button>
+            </Tooltip>
+            {loading && (
+              <Button type="primary" danger icon={<StopOutlined />} onClick={handleCancel}>
+                停止
               </Button>
-            </Tooltip>
-            <Dropdown menu={{ items: saveMoreMenuItems }} placement="bottomRight">
-                <Button>更多</Button>
-            </Dropdown>
-        </Button.Group>
-        
-        <Button.Group>
-            <Tooltip title="美化 SQL">
-                <Button icon={<FormatPainterOutlined />} onClick={handleFormat}>美化</Button>
-            </Tooltip>
-            <Dropdown menu={{ items: formatSettingsMenu }} placement="bottomRight">
-                <Button icon={<SettingOutlined />} />
-            </Dropdown>
-        </Button.Group>
+            )}
+          </Button.Group>
+          <Button.Group className={isV2Ui ? 'gn-v2-query-toolbar-action-group' : undefined}>
+              <Tooltip
+                  title={
+                      saveQueryShortcutBinding.enabled && saveQueryShortcutBinding.combo
+                          ? `保存（${getShortcutDisplayLabel(saveQueryShortcutBinding.combo, activeShortcutPlatform)}）`
+                          : '保存'
+                  }
+              >
+                <Button icon={<SaveOutlined />} onClick={handleQuickSave}>
+                  保存
+                </Button>
+              </Tooltip>
+              <Dropdown menu={{ items: saveMoreMenuItems }} placement="bottomRight">
+                  <Button>更多</Button>
+              </Dropdown>
+          </Button.Group>
 
-        <Dropdown menu={{ items: [
-            { key: 'ai-generate', label: '生成 SQL', icon: <RobotOutlined />, onClick: () => handleAIAction('generate') },
-            { key: 'ai-explain', label: '解释 SQL', icon: <RobotOutlined />, onClick: () => handleAIAction('explain') },
-            { key: 'ai-optimize', label: '优化 SQL', icon: <RobotOutlined />, onClick: () => handleAIAction('optimize') },
-            { type: 'divider' as const },
-            { key: 'ai-schema', label: 'Schema 分析', icon: <RobotOutlined />, onClick: () => handleAIAction('schema') },
-        ] }} placement="bottomRight">
-            <Button icon={<RobotOutlined />} style={{ color: '#818cf8' }}>AI</Button>
-        </Dropdown>
+          <Button.Group className={isV2Ui ? 'gn-v2-query-toolbar-action-group' : undefined}>
+              <Tooltip title="美化 SQL">
+                  <Button icon={<FormatPainterOutlined />} onClick={handleFormat}>美化</Button>
+              </Tooltip>
+              <Dropdown menu={{ items: formatSettingsMenu }} placement="bottomRight">
+                  <Button className={isV2Ui ? 'gn-v2-query-toolbar-icon-action' : undefined} icon={<SettingOutlined />} />
+              </Dropdown>
+          </Button.Group>
+
+          <Dropdown menu={{ items: [
+              { key: 'ai-generate', label: '生成 SQL', icon: <RobotOutlined />, onClick: () => handleAIAction('generate') },
+              { key: 'ai-explain', label: '解释 SQL', icon: <RobotOutlined />, onClick: () => handleAIAction('explain') },
+              { key: 'ai-optimize', label: '优化 SQL', icon: <RobotOutlined />, onClick: () => handleAIAction('optimize') },
+              { type: 'divider' as const },
+              { key: 'ai-schema', label: 'Schema 分析', icon: <RobotOutlined />, onClick: () => handleAIAction('schema') },
+          ] }} placement="bottomRight">
+              <Button className={isV2Ui ? 'gn-v2-query-toolbar-ai-action' : undefined} icon={<RobotOutlined />} style={{ color: '#818cf8' }}>AI</Button>
+          </Dropdown>
+        </div>
       </div>
       
       <div ref={editorShellRef} className={isV2Ui ? 'gn-v2-query-monaco-shell' : undefined} style={{ height: editorHeight, minHeight: '100px' }}>