refactor: replace cyan accent with ember orange across entire frontend

Swap accent color from cyan (#22d3ee) to ember orange (#f97316) site-wide.
Cyan caused contrast issues and felt generic — orange brings warmth and
urgency fitting for a troubleshooting tool.

Changes:
- CSS variables: accent, accent-hover, accent-dim, accent-text, primary, ring
- Warning color shifted from amber (#fbbf24) to yellow (#eab308) for
  semantic separation from orange accent
- Brand SVGs: logo gradient updated to orange
- 50+ component files: all hardcoded cyan hex values, Tailwind cyan-*
  classes, and rgba(34,211,238,...) glow values replaced
- landing.css: all 45+ cyan references + 5 old border color fixes
- DESIGN-SYSTEM.md bumped to v5 with decisions log
- CLAUDE.md: all color references synced to charcoal palette + orange accent
- PWA theme-color meta tag updated to match sidebar (#10121a)

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

frontend/src/components/dashboard/TeamSummary.tsx

@@ -19,8 +19,8 @@ export function TeamSummary() {
   if (!isAccountOwner) return null
 
   const items = [
-    { label: 'Escalations', value: escalationCount, icon: AlertTriangle, color: '#fbbf24', href: '/escalations' },
-    { label: 'Team Activity', value: '\u2014', icon: Activity, color: '#22d3ee', href: '/analytics' },
+    { label: 'Escalations', value: escalationCount, icon: AlertTriangle, color: '#eab308', href: '/escalations' },
+    { label: 'Team Activity', value: '\u2014', icon: Activity, color: '#f97316', href: '/analytics' },
     { label: 'Members', value: '\u2014', icon: Users, color: '#a78bfa', href: '/account' },
   ]