feat(l1): register /l1/* routes + L1RouteGuard + page stubs

L1RouteGuard wraps the new routes and redirects users without
canUseL1Surface back to /. Page components are stubs in this task
(real UI in T21-T24): L1Dashboard, L1WalkPage, L1DraftsPage,
L1TicketsPage.

Routes: /l1, /l1/walk/:sessionId, /l1/drafts, /l1/tickets — all gated.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

frontend/src/components/layout/L1RouteGuard.tsx

@@ -0,0 +1,10 @@
+import { Navigate } from 'react-router-dom'
+import { usePermissions } from '@/hooks/usePermissions'
+
+export function L1RouteGuard({ children }: { children: React.ReactNode }) {
+  const { canUseL1Surface } = usePermissions()
+  if (!canUseL1Surface) {
+    return <Navigate to="/" replace />
+  }
+  return <>{children}</>
+}

frontend/src/pages/l1/L1Dashboard.tsx

@@ -0,0 +1,13 @@
+import { PageMeta } from '@/components/common/PageMeta'
+
+export default function L1Dashboard() {
+  return (
+    <div className="overflow-y-auto h-full">
+      <PageMeta title="L1 Workspace" />
+      <div className="max-w-4xl mx-auto px-6 pt-12 pb-12">
+        <h1 className="font-heading text-2xl font-bold">L1 Workspace</h1>
+        <p className="text-muted-foreground mt-2">Loading…</p>
+      </div>
+    </div>
+  )
+}

frontend/src/pages/l1/L1DraftsPage.tsx

@@ -0,0 +1,13 @@
+import { PageMeta } from '@/components/common/PageMeta'
+
+export default function L1DraftsPage() {
+  return (
+    <div className="overflow-y-auto h-full">
+      <PageMeta title="My Drafts" />
+      <div className="max-w-4xl mx-auto px-6 pt-12 pb-12">
+        <h1 className="font-heading text-2xl font-bold">My Drafts</h1>
+        <p className="text-muted-foreground mt-2">Loading…</p>
+      </div>
+    </div>
+  )
+}

frontend/src/pages/l1/L1TicketsPage.tsx

@@ -0,0 +1,13 @@
+import { PageMeta } from '@/components/common/PageMeta'
+
+export default function L1TicketsPage() {
+  return (
+    <div className="overflow-y-auto h-full">
+      <PageMeta title="L1 Tickets" />
+      <div className="max-w-4xl mx-auto px-6 pt-12 pb-12">
+        <h1 className="font-heading text-2xl font-bold">L1 Tickets</h1>
+        <p className="text-muted-foreground mt-2">Loading…</p>
+      </div>
+    </div>
+  )
+}

frontend/src/pages/l1/L1WalkPage.tsx

@@ -0,0 +1,13 @@
+import { PageMeta } from '@/components/common/PageMeta'
+
+export default function L1WalkPage() {
+  return (
+    <div className="overflow-y-auto h-full">
+      <PageMeta title="L1 Walk" />
+      <div className="max-w-4xl mx-auto px-6 pt-12 pb-12">
+        <h1 className="font-heading text-2xl font-bold">L1 Walk</h1>
+        <p className="text-muted-foreground mt-2">Loading…</p>
+      </div>
+    </div>
+  )
+}

frontend/src/router.tsx

@@ -7,6 +7,7 @@ import { RouteError } from '@/components/common/RouteError'
 import { ErrorBoundary } from '@/components/common/ErrorBoundary'
 import { PageLoader } from '@/components/common/PageLoader'
 import { lazyWithRetry } from '@/lib/lazyWithRetry'
+import { L1RouteGuard } from '@/components/layout/L1RouteGuard'
 
 const sentryCreateBrowserRouter = Sentry.wrapCreateBrowserRouterV7(createBrowserRouter)
 import {
@@ -95,6 +96,12 @@ const AdminSurveyInvitesPage = lazyWithRetry(() => import('@/pages/admin/SurveyI
 const AdminSurveyResponsesPage = lazyWithRetry(() => import('@/pages/admin/SurveyResponsesPage'))
 const AdminGalleryManagementPage = lazyWithRetry(() => import('@/pages/admin/GalleryManagementPage'))
 
+// L1 workspace pages
+const L1Dashboard = lazyWithRetry(() => import('@/pages/l1/L1Dashboard'))
+const L1WalkPage = lazyWithRetry(() => import('@/pages/l1/L1WalkPage'))
+const L1DraftsPage = lazyWithRetry(() => import('@/pages/l1/L1DraftsPage'))
+const L1TicketsPage = lazyWithRetry(() => import('@/pages/l1/L1TicketsPage'))
+
 // Account pages
 const AccountLayout = lazyWithRetry(() => import('@/components/account/AccountLayout'))
 const ProfileSettingsPage = lazyWithRetry(() => import('@/pages/account/ProfileSettingsPage'))
@@ -284,6 +291,11 @@ export const router = sentryCreateBrowserRouter([
       { path: 'welcome/step-1', element: page(WelcomeStep1) },
       { path: 'welcome/step-2', element: page(WelcomeStep2) },
       { path: 'welcome/step-3', element: page(WelcomeStep3) },
+      // L1 workspace routes — gated by canUseL1Surface
+      { path: 'l1', element: <L1RouteGuard>{page(L1Dashboard)}</L1RouteGuard> },
+      { path: 'l1/walk/:sessionId', element: <L1RouteGuard>{page(L1WalkPage)}</L1RouteGuard> },
+      { path: 'l1/drafts', element: <L1RouteGuard>{page(L1DraftsPage)}</L1RouteGuard> },
+      { path: 'l1/tickets', element: <L1RouteGuard>{page(L1TicketsPage)}</L1RouteGuard> },
       // Admin routes
       {
         path: 'admin',