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/onboarding/WelcomeDialog.tsx

@@ -41,7 +41,7 @@ function Slide0() {
   return (
     <Box className="flex flex-col items-center text-center px-2">
       <Box className="mb-4">
-        <Building2 size={48} color="#1e3a5f" />
+        <Building2 size={48} color="#152642" />
       </Box>
       <Typography variant="h5" sx={{ fontWeight: 700, mb: 1 }}>
         Willkommen bei Property Match
@@ -74,7 +74,7 @@ function Slide1() {
   return (
     <Box className="flex flex-col items-center text-center px-2">
       <Box className="mb-4">
-        <Search size={48} color="#1e3a5f" />
+        <Search size={48} color="#152642" />
       </Box>
       <Typography variant="h5" sx={{ fontWeight: 700, mb: 1 }}>
         Bedarf beschreiben — KI findet Matches