feat: production hardening UI - tags page, onboarding wizard, pagination

- Tags management page: grid cards, rename/delete/merge modals, color-coded
- Onboarding wizard: 4-step full-screen flow for new users (welcome, client, style, tour)
- Client list pagination: page controls, page size selector, URL query params
- Pipeline view unaffected (shows all clients)
- Tags added to sidebar navigation
- All components support dark mode

src/App.tsx

@@ -23,6 +23,7 @@ const InvitePage = lazy(() => import('@/pages/InvitePage'));
 const ForgotPasswordPage = lazy(() => import('@/pages/ForgotPasswordPage'));
 const ResetPasswordPage = lazy(() => import('@/pages/ResetPasswordPage'));
 const AuditLogPage = lazy(() => import('@/pages/AuditLogPage'));
+const TagsPage = lazy(() => import('@/pages/TagsPage'));
 
 function ProtectedRoute({ children }: { children: React.ReactNode }) {
   const { isAuthenticated, isLoading } = useAuthStore();
@@ -76,6 +77,7 @@ export default function App() {
             <Route path="network" element={<PageErrorBoundary><NetworkPage /></PageErrorBoundary>} />
             <Route path="reports" element={<PageErrorBoundary><ReportsPage /></PageErrorBoundary>} />
             <Route path="templates" element={<PageErrorBoundary><TemplatesPage /></PageErrorBoundary>} />
+            <Route path="tags" element={<PageErrorBoundary><TagsPage /></PageErrorBoundary>} />
             <Route path="segments" element={<PageErrorBoundary><SegmentsPage /></PageErrorBoundary>} />
             <Route path="settings" element={<PageErrorBoundary><SettingsPage /></PageErrorBoundary>} />
             <Route path="admin" element={<PageErrorBoundary><AdminPage /></PageErrorBoundary>} />