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/pages/auth/LoginScreen.tsx

@@ -134,7 +134,7 @@ export default function LoginScreen() {
                 variant="contained"
                 fullWidth
                 disabled={loading}
-                sx={{ bgcolor: '#1e3a5f', textTransform: 'none', fontWeight: 600, '&:hover': { bgcolor: '#162d4a' } }}
+                sx={{ bgcolor: '#152642', textTransform: 'none', fontWeight: 600, '&:hover': { bgcolor: '#162d4a' } }}
               >
                 {loading ? <CircularProgress size={20} sx={{ color: '#fff' }} /> : 'Anmelden'}
               </Button>
@@ -146,7 +146,7 @@ export default function LoginScreen() {
         <Card elevation={0} sx={{ border: '1px solid #e2e8f0' }}>
           <CardContent sx={{ p: 3 }}>
             <Box sx={{ display: 'flex', alignItems: 'center', gap: 1, mb: 2 }}>
-              <Chip label="Demo" size="small" sx={{ bgcolor: '#1e3a5f', color: '#fff', fontSize: '0.7rem', height: 20 }} />
+              <Chip label="Demo" size="small" sx={{ bgcolor: '#152642', color: '#fff', fontSize: '0.7rem', height: 20 }} />
               <Typography variant="body2" sx={{ fontWeight: 600 }}>
                 Demo-Zugänge
               </Typography>
@@ -169,7 +169,7 @@ export default function LoginScreen() {
                     border: '1px solid #e2e8f0',
                     cursor: 'pointer',
                     transition: 'border-color 0.15s',
-                    '&:hover': { borderColor: '#1e3a5f', bgcolor: 'rgba(30,58,95,0.03)' },
+                    '&:hover': { borderColor: '#152642', bgcolor: 'rgba(30,58,95,0.03)' },
                   }}
                 >
                   <Box>