feat: redesign Schattenmarkt card & detail view for explainability

- Remove abstract Konfidenz/DQ badges from match detail header
- Replace ScoreBreakdownPanel with 3-step Bewertungsherleitung for
  FUTURE_AVAILABILITY: Kriterien-Match per factor with bars, Signal-
  Abschlag (verified ERP = kein Abschlag / probabilistic = -N Punkte),
  Gesamt-Score
- Restructure FutureAvailabilityContextPanel: source section first,
  verified ERP box for LEASE_CONTRACT, remove Konfidenz row, disclaimer
  as grey footnote instead of yellow alert
- Add LEASE_EXPIRY to signal type/relevance bridge labels
- Show up to 3 match reasons with explanation on cards (was 1)
- matchCardAdapter: return top-3 positive factors as reasons

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

src/components/match-card/IntelligenceMatchCard.tsx

@@ -258,7 +258,6 @@ export function IntelligenceMatchCard({ vm, imageUrl, lat, lng, cityLabel }: Pro
   const tier = getScoreTier(vm.matchScore)
   const theme = SCORE_THEME[tier]
   const rt = RESULT_TYPE_META[vm.resultType] ?? { label: vm.resultType, color: '#64748b' }
-  const topReason = vm.reasons[0]
   const isFuture = vm.resultType === 'FUTURE_AVAILABILITY'
 
   return (
@@ -360,14 +359,23 @@ export function IntelligenceMatchCard({ vm, imageUrl, lat, lng, cityLabel }: Pro
           </>
         )}
 
-        {topReason && (
+        {vm.reasons.length > 0 && (
           <>
             <Divider sx={{ my: 1.25 }} />
-            <Box sx={{ display: 'flex', alignItems: 'flex-start', gap: 0.75 }}>
-              <CheckCircle2 size={13} color="#1a7a4a" style={{ marginTop: 2, flexShrink: 0 }} />
-              <Typography variant="caption" sx={{ color: '#1a7a4a', fontWeight: 600, lineHeight: 1.4 }}>
-                {topReason.label}
-              </Typography>
+            <Box sx={{ display: 'flex', flexDirection: 'column', gap: 0.625 }}>
+              {vm.reasons.slice(0, 3).map((r, i) => (
+                <Box key={i} sx={{ display: 'flex', alignItems: 'flex-start', gap: 0.75 }}>
+                  <CheckCircle2 size={13} color="#1a7a4a" style={{ marginTop: 2, flexShrink: 0 }} />
+                  <Box>
+                    <Typography sx={{ fontSize: '0.75rem', fontWeight: 600, color: '#1e293b', lineHeight: 1.3 }}>
+                      {r.label}
+                    </Typography>
+                    <Typography sx={{ fontSize: '0.72rem', color: '#64748b', lineHeight: 1.3 }}>
+                      {r.explanation}
+                    </Typography>
+                  </Box>
+                </Box>
+              ))}
             </Box>
           </>
         )}