feat: replace hardcoded orange hex values with blue equivalents

BrandLogo gradient, EmptyStateIllustrations SVGs, categoryColors,
landing page, brand SVG assets, and all remaining files.
Warning #eab308 → #fbbf24 (amber). categoryColors deduped.

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: '#eab308',
+  workaround: '#fbbf24',
   unresolved: '#94a3b8',
 }
 

frontend/src/components/analytics/PsaMetricsPanel.tsx

@@ -102,14 +102,14 @@ export default function PsaMetricsPanel({ data }: PsaMetricsPanelProps) {
                 yAxisId="hours"
                 type="monotone"
                 dataKey="hours"
-                stroke="#f97316"
+                stroke="#60a5fa"
                 fill="url(#psaHoursGradient)"
                 strokeWidth={2}
               />
               <defs>
                 <linearGradient id="psaHoursGradient" x1="0" y1="0" x2="0" y2="1">
-                  <stop offset="5%" stopColor="#f97316" stopOpacity={0.3} />
-                  <stop offset="95%" stopColor="#f97316" stopOpacity={0} />
+                  <stop offset="5%" stopColor="#60a5fa" stopOpacity={0.3} />
+                  <stop offset="95%" stopColor="#60a5fa" stopOpacity={0} />
                 </linearGradient>
               </defs>
             </ComposedChart>