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/analytics/FlowAnalyticsPanel.tsx

@@ -16,7 +16,7 @@ import type { FlowAnalyticsResponse, AnalyticsPeriod } from '@/types'
 const CHART_COLORS = {
   resolved: '#34d399',
   escalated: '#f87171',
-  workaround: '#fbbf24',
+  workaround: '#eab308',
   unresolved: '#94a3b8',
 }
 

frontend/src/components/analytics/PsaMetricsPanel.tsx

@@ -95,21 +95,21 @@ export default function PsaMetricsPanel({ data }: PsaMetricsPanelProps) {
               <Bar
                 yAxisId="entries"
                 dataKey="entries"
-                fill="rgba(34,211,238,0.3)"
+                fill="rgba(249,115,22,0.3)"
                 radius={[4, 4, 0, 0]}
               />
               <Area
                 yAxisId="hours"
                 type="monotone"
                 dataKey="hours"
-                stroke="#22d3ee"
+                stroke="#f97316"
                 fill="url(#psaHoursGradient)"
                 strokeWidth={2}
               />
               <defs>
                 <linearGradient id="psaHoursGradient" x1="0" y1="0" x2="0" y2="1">
-                  <stop offset="5%" stopColor="#22d3ee" stopOpacity={0.3} />
-                  <stop offset="95%" stopColor="#22d3ee" stopOpacity={0} />
+                  <stop offset="5%" stopColor="#f97316" stopOpacity={0.3} />
+                  <stop offset="95%" stopColor="#f97316" stopOpacity={0} />
                 </linearGradient>
               </defs>
             </ComposedChart>