♻️ refactor(sidebar): 抽出 ConnectionRail 为独立子组件

- 新建 sidebar/SidebarConnectionRail.tsx：V2 连接栏（新建分组/批量导出/SQL 文件/定位/AI/工具/设置 7 个按钮）
- Props 用聚合对象（labels + handlers + canLocateActiveTab）避免 18+ 个独立 props drilling
- Sidebar.tsx 删除 renderV2ConnectionRail（-93 行），加 v2ConnectionRailProps 构造 + <SidebarConnectionRail /> 调用
- Sidebar.tsx 从 10187 减至 10122 行

frontend/src/components/Sidebar.tsx

@@ -1,4 +1,5 @@
 import Modal from './common/ResizableDraggableModal';
+import SidebarConnectionRail from './sidebar/SidebarConnectionRail';
 import {
   V2_RAIL_UNGROUPED_CONNECTION_GROUP_ID,
   formatSidebarRowCount,
@@ -9162,104 +9163,38 @@ const Sidebar: React.FC<{
   const v2CommandSearchLabel = t('sidebar.command_search.label');
   const v2CommandSearchPlaceholder = t('sidebar.command_search.placeholder');
 
-  const renderV2ConnectionRail = () => (
-      <div className="gn-v2-connection-rail" aria-label={v2RailSystemActionsLabel}>
-          <div className="gn-v2-rail-primary-actions" aria-label={v2RailObjectActionsLabel}>
-              <Tooltip title={v2NewGroupLabel} placement="right">
-                  <button
-                      type="button"
-                      className="gn-v2-rail-tool gn-v2-rail-action"
-                      onClick={() => { setRenameViewTarget(null); createTagForm.resetFields(); setIsCreateTagModalOpen(true); }}
-                      aria-label={v2NewGroupLabel}
-                      data-sidebar-create-group-action="true"
-                  >
-                      <FolderOpenOutlined />
-                  </button>
-              </Tooltip>
-              <Tooltip title={v2BatchTablesLabel} placement="right">
-                  <button
-                      type="button"
-                      className="gn-v2-rail-tool gn-v2-rail-action"
-                      onClick={() => openBatchTableExportWorkbench()}
-                      aria-label={v2BatchTablesLabel}
-                      data-sidebar-batch-table-action="true"
-                  >
-                      <TableOutlined />
-                  </button>
-              </Tooltip>
-              <Tooltip title={v2BatchDatabasesLabel} placement="right">
-                  <button
-                      type="button"
-                      className="gn-v2-rail-tool gn-v2-rail-action"
-                      onClick={() => openBatchDatabaseExportWorkbench()}
-                      aria-label={v2BatchDatabasesLabel}
-                      data-sidebar-batch-database-action="true"
-                  >
-                      <DatabaseOutlined />
-                  </button>
-              </Tooltip>
-              <Tooltip title={v2OpenExternalSqlFileLabel} placement="right">
-                  <button
-                      type="button"
-                      className="gn-v2-rail-tool gn-v2-rail-action"
-                      onClick={handleOpenSQLFileFromToolbar}
-                      aria-label={v2OpenExternalSqlFileLabel}
-                      data-sidebar-open-external-sql-file-action="true"
-                  >
-                      <FileAddOutlined />
-                  </button>
-              </Tooltip>
-              <Tooltip title={canLocateActiveTab ? v2LocateCurrentTableLabel : v2LocateCurrentTableUnavailableLabel} placement="right">
-                  <span className="gn-v2-rail-action-wrap">
-                      <button
-                           type="button"
-                           className="gn-v2-rail-tool gn-v2-rail-action"
-                           onClick={handleLocateActiveTabInSidebar}
-                           aria-label={v2LocateCurrentTableLabel}
-                           data-sidebar-locate-current-tab-action="true"
-                           disabled={!canLocateActiveTab}
-                       >
-                          <AimOutlined />
-                      </button>
-                  </span>
-              </Tooltip>
-          </div>
-          <div className="gn-v2-rail-secondary-actions" aria-label={v2RailSystemActionsLabel}>
-              <Tooltip title={v2AiAssistantLabel} placement="right">
-                  <button
-                      type="button"
-                      className="gn-v2-rail-tool"
-                      onClick={onToggleAI}
-                      aria-label={v2AiAssistantLabel}
-                      data-gonavi-ai-entry-action="true"
-                  >
-                      <RobotOutlined />
-                  </button>
-              </Tooltip>
-              <Tooltip title={v2ToolsLabel} placement="right">
-                  <button
-                      type="button"
-                      className="gn-v2-rail-tool"
-                      onClick={onOpenTools}
-                      aria-label={v2ToolsLabel}
-                      data-gonavi-open-tools-action="true"
-                  >
-                      <ToolOutlined />
-                  </button>
-              </Tooltip>
-              <Tooltip title={v2SettingsLabel} placement="right">
-                  <button type="button" className="gn-v2-rail-tool" onClick={onOpenSettings} aria-label={v2SettingsLabel}>
-                      <SettingOutlined />
-                  </button>
-              </Tooltip>
-          </div>
-      </div>
-  );
+  // V2 Connection Rail 子组件 props（从原 renderV2ConnectionRail 抽出，保留所有原行为）
+  const v2ConnectionRailProps = {
+    labels: {
+      railSystemActions: v2RailSystemActionsLabel,
+      railObjectActions: v2RailObjectActionsLabel,
+      newGroup: v2NewGroupLabel,
+      batchTables: v2BatchTablesLabel,
+      batchDatabases: v2BatchDatabasesLabel,
+      openExternalSqlFile: v2OpenExternalSqlFileLabel,
+      locateCurrentTable: v2LocateCurrentTableLabel,
+      locateCurrentTableUnavailable: v2LocateCurrentTableUnavailableLabel,
+      aiAssistant: v2AiAssistantLabel,
+      tools: v2ToolsLabel,
+      settings: v2SettingsLabel,
+    },
+    handlers: {
+      openCreateTagModal: () => { setRenameViewTarget(null); createTagForm.resetFields(); setIsCreateTagModalOpen(true); },
+      openBatchTableExport: () => openBatchTableExportWorkbench(),
+      openBatchDatabaseExport: () => openBatchDatabaseExportWorkbench(),
+      openExternalSqlFile: handleOpenSQLFileFromToolbar,
+      locateActiveTab: handleLocateActiveTabInSidebar,
+      toggleAI: onToggleAI ?? (() => {}),
+      openTools: onOpenTools ?? (() => {}),
+      openSettings: onOpenSettings ?? (() => {}),
+    },
+    canLocateActiveTab,
+  };
 
   return (
     <div className={isV2Ui ? 'gn-v2-sidebar-redesign' : undefined} style={{ display: 'flex', height: '100%', minHeight: 0 }}>
         {exportProgressModal}
-        {isV2Ui && renderV2ConnectionRail()}
+        {isV2Ui && <SidebarConnectionRail {...v2ConnectionRailProps} />}
         <div className={isV2Ui ? 'gn-v2-object-explorer' : undefined} style={{ display: 'flex', flexDirection: 'column', height: '100%', minWidth: 0, flex: 1 }}>
         {isV2Ui && (
             <div className="gn-v2-active-connection-header" data-object-count={activeConnectionObjectCount}>

frontend/src/components/sidebar/SidebarConnectionRail.tsx

@@ -0,0 +1,144 @@
+import React from 'react';
+import { Tooltip, Form } from 'antd';
+import {
+  FolderOpenOutlined,
+  TableOutlined,
+  DatabaseOutlined,
+  FileAddOutlined,
+  AimOutlined,
+  RobotOutlined,
+  ToolOutlined,
+  SettingOutlined,
+} from '@ant-design/icons';
+
+// V2 Connection Rail 子组件（从 Sidebar.tsx 抽取）。
+//
+// 注意：本组件是 Sidebar.tsx 拆分的一部分，依赖大量主组件的 label/state/handler。
+// 通过聚合 props 对象传递，避免 18+ 个独立 props 的 drilling 噪音。
+// 后续状态管理重构（PR-A）会把 labels/handlers 迁到 useSidebarUIState hook。
+//
+// 设计取舍：用 labels + handlers 聚合对象 + FormInstance，换取 Sidebar.tsx 减少 ~100 行。
+// 主组件 props drilling 复杂度可控（只有一处调用点）。
+
+export interface SidebarConnectionRailProps {
+  labels: {
+    railSystemActions: string;
+    railObjectActions: string;
+    newGroup: string;
+    batchTables: string;
+    batchDatabases: string;
+    openExternalSqlFile: string;
+    locateCurrentTable: string;
+    locateCurrentTableUnavailable: string;
+    aiAssistant: string;
+    tools: string;
+    settings: string;
+  };
+  handlers: {
+    openCreateTagModal: () => void;
+    openBatchTableExport: () => void;
+    openBatchDatabaseExport: () => void;
+    openExternalSqlFile: () => void;
+    locateActiveTab: () => void;
+    toggleAI: () => void;
+    openTools: () => void;
+    openSettings: () => void;
+  };
+  canLocateActiveTab: boolean;
+}
+
+const SidebarConnectionRail: React.FC<SidebarConnectionRailProps> = ({ labels, handlers, canLocateActiveTab }) => (
+  <div className="gn-v2-connection-rail" aria-label={labels.railSystemActions}>
+    <div className="gn-v2-rail-primary-actions" aria-label={labels.railObjectActions}>
+      <Tooltip title={labels.newGroup} placement="right">
+        <button
+          type="button"
+          className="gn-v2-rail-tool gn-v2-rail-action"
+          onClick={handlers.openCreateTagModal}
+          aria-label={labels.newGroup}
+          data-sidebar-create-group-action="true"
+        >
+          <FolderOpenOutlined />
+        </button>
+      </Tooltip>
+      <Tooltip title={labels.batchTables} placement="right">
+        <button
+          type="button"
+          className="gn-v2-rail-tool gn-v2-rail-action"
+          onClick={handlers.openBatchTableExport}
+          aria-label={labels.batchTables}
+          data-sidebar-batch-table-action="true"
+        >
+          <TableOutlined />
+        </button>
+      </Tooltip>
+      <Tooltip title={labels.batchDatabases} placement="right">
+        <button
+          type="button"
+          className="gn-v2-rail-tool gn-v2-rail-action"
+          onClick={handlers.openBatchDatabaseExport}
+          aria-label={labels.batchDatabases}
+          data-sidebar-batch-database-action="true"
+        >
+          <DatabaseOutlined />
+        </button>
+      </Tooltip>
+      <Tooltip title={labels.openExternalSqlFile} placement="right">
+        <button
+          type="button"
+          className="gn-v2-rail-tool gn-v2-rail-action"
+          onClick={handlers.openExternalSqlFile}
+          aria-label={labels.openExternalSqlFile}
+          data-sidebar-open-external-sql-file-action="true"
+        >
+          <FileAddOutlined />
+        </button>
+      </Tooltip>
+      <Tooltip title={canLocateActiveTab ? labels.locateCurrentTable : labels.locateCurrentTableUnavailable} placement="right">
+        <span className="gn-v2-rail-action-wrap">
+          <button
+            type="button"
+            className="gn-v2-rail-tool gn-v2-rail-action"
+            onClick={handlers.locateActiveTab}
+            aria-label={labels.locateCurrentTable}
+            data-sidebar-locate-current-tab-action="true"
+            disabled={!canLocateActiveTab}
+          >
+            <AimOutlined />
+          </button>
+        </span>
+      </Tooltip>
+    </div>
+    <div className="gn-v2-rail-secondary-actions" aria-label={labels.railSystemActions}>
+      <Tooltip title={labels.aiAssistant} placement="right">
+        <button
+          type="button"
+          className="gn-v2-rail-tool"
+          onClick={handlers.toggleAI}
+          aria-label={labels.aiAssistant}
+          data-gonavi-ai-entry-action="true"
+        >
+          <RobotOutlined />
+        </button>
+      </Tooltip>
+      <Tooltip title={labels.tools} placement="right">
+        <button
+          type="button"
+          className="gn-v2-rail-tool"
+          onClick={handlers.openTools}
+          aria-label={labels.tools}
+          data-gonavi-open-tools-action="true"
+        >
+          <ToolOutlined />
+        </button>
+      </Tooltip>
+      <Tooltip title={labels.settings} placement="right">
+        <button type="button" className="gn-v2-rail-tool" onClick={handlers.openSettings} aria-label={labels.settings}>
+          <SettingOutlined />
+        </button>
+      </Tooltip>
+    </div>
+  </div>
+);
+
+export default SidebarConnectionRail;