feat: Objekt→Einheit architecture — unit-level pre-market, property detail page, click-through from cards

- Domain: PropertyUnit extended with propertyId + schattenmarktRelease per unit
- Domain: FutureAvailabilityResult carries resolved property + unit
- useSchattenmarktSignals: generates unit-level signals (schattenmarkt-{propId}-{unitId})
- useUnifiedResults: resolves backing property + unit on FUTURE_AVAILABILITY fast path
- IUnitProvider + MockupUnitProvider: first-class unit access and mutation
- matchCardAdapter: maps preMarketUnit, preMarketAllUnits, propertyId, unitId to ViewModel
- IntelligenceMatchCard: PRE-MARKET VERIFIED shows unit info strip + "Zur Einheit →" button
- PropertyDetailView: unit-level toggles + date pickers inside PreMarketPanel
- New page: /demand/property/:propertyId with unit table, status chips, inquiry form
- App.tsx: demand route /demand/property/:propertyId registered
- Mock data: prop-001/007/037 units updated with correct lease dates + unit-level schattenmarktRelease

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

src/App.tsx

@@ -34,6 +34,7 @@ const MatchDetail = lazy(() => import('./pages/demand/MatchDetail'))
 const Compare = lazy(() => import('./pages/demand/Compare'))
 const Shortlists = lazy(() => import('./pages/demand/Shortlists'))
 const Pipeline = lazy(() => import('./pages/demand/Pipeline'))
+const PropertyDetail = lazy(() => import('./pages/demand/PropertyDetail'))
 
 const MarketIntelligence = lazy(() => import('./pages/ops/MarketIntelligence'))
 
@@ -71,6 +72,7 @@ function App() {
                 <Route path="/demand/compare" element={<Compare />} />
                 <Route path="/demand/shortlists" element={<Shortlists />} />
                 <Route path="/demand/pipeline" element={<Pipeline />} />
+                <Route path="/demand/property/:propertyId" element={<PropertyDetail />} />
               </Route>