feat: premium redesign — DM Serif, refined palette, flat score badges

- Design tokens (ds.ts, theme.ts, scoreTheme.ts): new warm palette
  (#152642 navy, #f9f8f6 warm white, #e8e7e4 borders, #b8975a gold accent),
  flat score tier badges replacing CSS gradients, Inter + DM Serif Display typography
- Card components: white-background cards, DM Serif score numbers, max-2 badge
  chips with +N overflow tooltip, editorial score badge positioning
- Layout shell: gold left-accent nav active state, 64px top bar, outlined
  workspace chip, DM Serif page titles
- Shared atoms: GenericBadge (outlined/solid variants), ResultFilterBar
  (simplified chip styles), DecisionContextPanel (dot metrics, no left accent)
- Global replacement (118 files): #1e3a5f→#152642, #e2e8f0→#e8e7e4,
  #f4f6f9→#f9f8f6 — all handled via Node.js for proper UTF-8 safety

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/components/cards/MetricCard.tsx

@@ -17,7 +17,7 @@ interface MetricCardProps {
   sx?: SxProps<Theme>
 }
 
-export function MetricCard({ label, value, delta, icon, color = '#1e3a5f', sx }: MetricCardProps) {
+export function MetricCard({ label, value, delta, icon, color = '#152642', sx }: MetricCardProps) {
   return (
     <Card sx={{ p: 2.5, ...sx }}>
       <Box sx={{ display: 'flex', alignItems: 'flex-start', justifyContent: 'space-between' }}>

src/components/cards/SourceTypeBadge.tsx

@@ -9,7 +9,7 @@ interface SourceTypeBadgeProps {
 }
 
 const CONFIG: Record<string, { bg: string; color: string; Icon: React.ElementType }> = {
-  VERIFIED_PORTFOLIO:  { bg: 'rgba(30,58,95,0.1)',   color: '#1e3a5f', Icon: ShieldCheck },
+  VERIFIED_PORTFOLIO:  { bg: 'rgba(30,58,95,0.1)',   color: '#152642', Icon: ShieldCheck },
   MAISON_WORK:         { bg: 'rgba(3,105,161,0.1)',  color: '#0369a1', Icon: Building2 },
   FUTURE_AVAILABILITY: { bg: 'rgba(124,58,237,0.1)', color: '#6d28d9', Icon: Sparkles },
 }