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

frontend/src/components/RibbonBar.tsx

@@ -1,6 +1,7 @@
 import React from 'react';
 import type { RibbonBarProps, RibbonTab } from '../types/ui.types';
 import { pluginRegistry } from '../plugins';
+import { V2_TOOLS_ENABLED } from '../kernel/featureFlags';
 
 const tabs: Array<{ id: RibbonTab; label: string; svg: React.ReactNode }> = [
   { id: 'start', label: 'Start', svg: <svg viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2" strokeLinecap="round" strokeLinejoin="round"><path d="m3 9 9-7 9 7v11a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2z"/><polyline points="9 22 9 12 15 12 15 22"/></svg> },
@@ -38,8 +39,8 @@ const RibbonBar: React.FC<RibbonBarProps> = ({
       </div>
 
       <div className="ribbon-content" id="ribbon-content">
-        {/* ===== V2 TOOLS (Task A4.13, nur bei aktivem Dispatcher-Flag) ===== */}
-        {activeTab === 'canvas' && import.meta.env.VITE_TOOL_DISPATCHER === 'v2' && (
+        {/* ===== V2 TOOLS (Task A4.13/A4.14: Standard aktiv — Opt-out via VITE_TOOL_DISPATCHER=legacy) ===== */}
+        {activeTab === 'canvas' && V2_TOOLS_ENABLED && (
           <div style={{
             display: 'flex', flexWrap: 'wrap', gap: '6px', alignItems: 'center',
             padding: '8px 4px', width: '100%',
@@ -51,6 +52,7 @@ const RibbonBar: React.FC<RibbonBarProps> = ({
               return (
                 <button
                   key={tool.manifest.id}
+                  data-v2tool={tool.manifest.id}
                   title={tool.manifest.description ?? tool.manifest.label}
                   onClick={() => onAction(`v2tool:${tool.manifest.id}`)}
                   style={{