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/dashboard/PendingEscalations.tsx

@@ -0,0 +1,87 @@
+import { useState, useEffect } from 'react'
+import { Link, useNavigate } from 'react-router-dom'
+import { AlertTriangle } from 'lucide-react'
+import { aiSessionsApi } from '@/api/aiSessions'
+import type { AISessionSummary } from '@/types/ai-session'
+
+function timeAgo(dateStr: string): string {
+  const diffMs = Date.now() - new Date(dateStr).getTime()
+  const minutes = Math.floor(diffMs / 60000)
+  if (minutes < 1) return 'just now'
+  if (minutes < 60) return `${minutes}m ago`
+  const hours = Math.floor(minutes / 60)
+  if (hours < 24) return `${hours}h ago`
+  return `${Math.floor(hours / 24)}d ago`
+}
+
+export function PendingEscalations() {
+  const [escalations, setEscalations] = useState<AISessionSummary[]>([])
+  const navigate = useNavigate()
+
+  useEffect(() => {
+    aiSessionsApi.getEscalationQueue()
+      .then(setEscalations)
+      .catch(() => {})
+  }, [])
+
+  if (escalations.length === 0) return null
+
+  return (
+    <div
+      className="glass-card-static overflow-hidden"
+      style={{ borderColor: 'rgba(251, 191, 36, 0.2)' }}
+    >
+      <div
+        className="flex items-center justify-between px-5 py-3"
+        style={{ borderBottom: '1px solid var(--glass-border)' }}
+      >
+        <div className="flex items-center gap-2">
+          <AlertTriangle size={14} className="text-amber-400" />
+          <h3 className="font-heading text-sm font-bold text-foreground">
+            Pending Escalations
+            <span className="ml-2 inline-flex h-5 min-w-5 items-center justify-center rounded-full bg-amber-400/10 px-1.5 text-[0.625rem] font-bold text-amber-400">
+              {escalations.length}
+            </span>
+          </h3>
+        </div>
+        <Link
+          to="/escalations"
+          className="text-[0.6875rem] text-muted-foreground hover:text-foreground transition-colors"
+        >
+          View all
+        </Link>
+      </div>
+      <div>
+        {escalations.slice(0, 3).map((esc, i) => (
+          <div
+            key={esc.id}
+            className="flex items-center gap-3 px-5 py-3"
+            style={{
+              borderBottom: i < Math.min(escalations.length, 3) - 1
+                ? '1px solid var(--glass-border)'
+                : undefined,
+            }}
+          >
+            <span className="h-2 w-2 shrink-0 rounded-full bg-amber-400 animate-pulse" />
+            <div className="flex-1 min-w-0">
+              <div className="text-sm text-foreground truncate">
+                {esc.problem_summary || 'Escalated session'}
+              </div>
+              <div className="text-[0.6875rem] text-muted-foreground">
+                {esc.problem_domain || 'General'}
+                <span className="mx-1.5 text-[var(--text-dimmed)]">&middot;</span>
+                <span className="font-label text-[0.625rem]">{timeAgo(esc.created_at)}</span>
+              </div>
+            </div>
+            <button
+              onClick={() => navigate(`/pilot/${esc.id}?pickup=true`)}
+              className="shrink-0 rounded-lg border border-amber-400/30 bg-amber-400/10 px-3 py-1 text-[0.6875rem] font-medium text-amber-400 hover:bg-amber-400/20 transition-colors"
+            >
+              Pick up
+            </button>
+          </div>
+        ))}
+      </div>
+    </div>
+  )
+}