feat: Future Availability Intelligence — rebrand & card redesign

Replaces "Schattenmarkt" branding with professional Future Availability
Intelligence throughout the UI. Two distinct card types: Pre-Market
(LEASE_EXPIRY + verified, green accent) and Market Signal (probabilistic,
blue accent). Professioneller Data-Header replaces dark purple gradient.
New detail panel sections: Erkannte Marktindikatoren, Strategische
Interpretation, Bestätigt/Nicht bestätigt. All 15 mock signals enriched
with concrete Swiss CRE market indicators and strategic interpretations.
Signal quality shown as 4-dot indicator (Hoch/Mittel/Niedrig).

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

src/pages/demand/MatchDetail.tsx

@@ -172,7 +172,7 @@ export default function MatchDetail() {
           sx={{ bgcolor: '#f1f5f9', color: '#475569', fontWeight: 700, letterSpacing: 0.5 }}
         />
         {isFuture && (
-          <Chip label="Probabilistisches Signal" size="small" sx={{ bgcolor: '#faf5ff', color: '#7c3aed', fontWeight: 600 }} />
+          <Chip label="Future Availability Signal" size="small" sx={{ bgcolor: '#faf5ff', color: '#7c3aed', fontWeight: 600 }} />
         )}
       </Box>