feat: bold dashboard redesign with inline stats, section labels, and chip icons

Restructure QuickStartPage for a more professional, informative layout:
- Left-aligned hero greeting (text-4xl) with date context and inline stat strip
- GreetingStatStrip shows resolved/active/MTTR at a glance
- Remove collapsible toggle — dashboard stats always visible
- Section labels with trailing border lines for visual hierarchy
- Suggestion chips with category icons, card-style hover, press feedback
- Fix cyan focus ring and icon color to ember orange design system
- Session cards: line-clamp-2 descriptions, font-medium text, problem_domain metadata
- Widen container max-w-3xl → max-w-4xl for breathing room
- Add .impeccable.md and .github/copilot-instructions.md design context
- CLAUDE.md audit: fix stale references, remove duplication, update counts

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/components/dashboard/GreetingStatStrip.tsx

@@ -0,0 +1,54 @@
+import { useState, useEffect } from 'react'
+import { CheckCircle, Clock, Zap } from 'lucide-react'
+import type { LucideIcon } from 'lucide-react'
+import { sidebarApi } from '@/api'
+
+interface StatItem {
+  icon: LucideIcon
+  value: string | number | null
+  label: string
+  color: string
+}
+
+export function GreetingStatStrip() {
+  const [resolved, setResolved] = useState<number | null>(null)
+  const [active, setActive] = useState<number | null>(null)
+  const [avgMttr, setAvgMttr] = useState<string | null>(null)
+
+  useEffect(() => {
+    sidebarApi.getStats()
+      .then((stats) => {
+        setResolved(stats.resolved_today)
+        setActive(stats.active_count)
+        const avg = stats.resolved_today > 0
+          ? Math.round(stats.total_session_minutes_today / stats.resolved_today)
+          : null
+        setAvgMttr(avg != null ? `${avg}m` : null)
+      })
+      .catch(() => {})
+  }, [])
+
+  const stats: StatItem[] = [
+    { icon: CheckCircle, value: resolved, label: 'resolved today', color: '#34d399' },
+    { icon: Zap, value: active, label: 'active now', color: '#f97316' },
+    { icon: Clock, value: avgMttr, label: 'avg MTTR', color: '#848b9b' },
+  ]
+
+  return (
+    <div className="hidden sm:flex items-center gap-5 pb-1">
+      {stats.map(({ icon: Icon, value, label, color }) => (
+        <div key={label} className="flex items-center gap-2">
+          <Icon size={13} style={{ color }} className="shrink-0" />
+          <div className="text-right">
+            <p className="font-heading text-lg font-extrabold leading-none text-[#f0f2f5]">
+              {value ?? '\u2014'}
+            </p>
+            <p className="font-sans text-[0.5625rem] uppercase tracking-[0.1em] text-muted-foreground mt-0.5">
+              {label}
+            </p>
+          </div>
+        </div>
+      ))}
+    </div>
+  )
+}