feat(dashboard): FlowPilot cockpit dashboard + sidebar redesign

- Replace QuickStartPage with FlowPilot-centric dashboard
- Add StartSessionInput with Guided/Chat mode toggle
- Add PendingEscalations, ActiveFlowPilotSessions, PerformanceCards
- Add KnowledgeBaseCards, TeamSummary, RecentFlowPilotSessions
- Every number/card is a portal to its detail page
- Restructure sidebar: Resolve/Knowledge/Insights sections
- Remove redundant nav items (FlowPilot, Flow Editor, Flow Assist, etc.)
- Wire prefill from dashboard input to FlowPilot intake
- Update mobile nav to match new sidebar structure

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/components/layout/AppLayout.tsx

@@ -1,6 +1,6 @@
 import { useEffect, useState, useCallback } from 'react'
 import { useLocation, useNavigate, Link } from 'react-router-dom'
-import { Menu, X, LayoutGrid, Box, PenLine, Clock, FileText, Bookmark, Settings, LogOut, Shield, Terminal } from 'lucide-react'
+import { Menu, X, LayoutGrid, Clock, Network, AlertTriangle, Code2, BarChart3, Settings, LogOut, Shield, Library } from 'lucide-react'
 import { useAuthStore } from '@/store/authStore'
 import { usePermissions } from '@/hooks/usePermissions'
 import { useUserPreferencesStore } from '@/store/userPreferencesStore'
@@ -52,12 +52,12 @@ export function AppLayout() {
 
   const mobileNavItems = [
     { path: '/', label: 'Dashboard', icon: LayoutGrid },
-    { path: '/trees', label: 'All Flows', icon: Box },
-    { path: '/my-trees', label: 'My Flows', icon: PenLine },
-    { path: '/sessions', label: 'Sessions', icon: Clock },
-    { path: '/shares', label: 'Exports', icon: FileText },
-    { path: '/step-library', label: 'Step Library', icon: Bookmark },
-    { path: '/scripts', label: 'Script Library', icon: Terminal },
+    { path: '/sessions', label: 'Active Sessions', icon: Clock },
+    { path: '/escalations', label: 'Escalations', icon: AlertTriangle },
+    { path: '/trees', label: 'Flows', icon: Network },
+    { path: '/step-library', label: 'Step Library', icon: Library },
+    { path: '/scripts', label: 'Scripts', icon: Code2 },
+    { path: '/analytics', label: 'Analytics', icon: BarChart3 },
     { path: '/account', label: 'Account', icon: Settings },
   ]