task(A4.14): make v2 tool path the default (verified e2e without flag)

frontend/src/App.tsx

@@ -19,6 +19,7 @@ import MobileDrawers from './components/MobileDrawers';
 import BackgroundImport from './components/BackgroundImport';
 import HistoryPanel from './components/HistoryPanel';
 import V2HistoryPanel from './components/V2HistoryPanel';
+import { V2_TOOLS_ENABLED } from './kernel/featureFlags';
 import SettingsModal from './components/SettingsModal';
 import InlineTextEditor from './components/InlineTextEditor';
 import { BackgroundService, type BackgroundConfig } from './services/backgroundService';
@@ -1574,7 +1575,7 @@ const CADEditor: React.FC<CADEditorProps> = ({ projectId, token, onNavigateBack
         onTabChange={setActiveRibbonTab}
         onAction={handleRibbonAction}
         onIsV2ToolActive={(toolId: string) =>
-          import.meta.env.VITE_TOOL_DISPATCHER === 'v2' &&
+          V2_TOOLS_ENABLED &&
           activeTool === toolId &&
           !!pluginRegistry.getToolV2(toolId)
         }
@@ -1743,7 +1744,7 @@ const CADEditor: React.FC<CADEditorProps> = ({ projectId, token, onNavigateBack
         onApply={handleBgApply}
         backgroundService={bgServiceRef.current}
       />
-      {historyPanelOpen && (import.meta.env.VITE_TOOL_DISPATCHER === 'v2' ? (
+      {historyPanelOpen && (V2_TOOLS_ENABLED ? (
         <V2HistoryPanel
           onClose={() => setHistoryPanelOpen(false)}
         />