feat: Reminder Manager + Schattenmarkt-Freigabe + mock data overhaul

- Add Reminder Manager page (/supply/reminder-manager) with KPI bar,
  filter bar, list/card feed, and detail drawer (7 sections incl.
  activity log, snooze, complete, dismiss actions)
- Add Schattenmarkt-Freigabe toggle on PropertyDetailView: Verwaltung
  can opt-in properties for early market exposure before contract expiry
- Auto-generate FutureSignal cards via useSchattenmarktSignals hook
  when leaseEndDate - leadTimeMonths <= MOCK_TODAY
- Fix useUnifiedResults: use property.resultType as fallback (was
  defaulting everything to VERIFIED_PORTFOLIO)
- Fix demand Results: hide VERIFIED_PORTFOLIO from non-manager users
  even when showOwnProperties toggle was previously enabled
- Fix AppShell: redirect to allowed workspace on user role switch
- Fix 3 wrong match scores (match-002: 93→62, match-009: 86→55,
  match-017: 87→52)
- Add 7 new match records (match-050–056) for need-001, need-002,
  need-011
- Add need-011 (Retail Bern Innenstadt)
- Add prop-031–036 (EXTERNAL_MARKET / MAISON_WORK / FUTURE_AVAILABILITY)
- Fix duplicate image URLs across all properties
- Add signal-011 (Bern Altstadt, Mode Boutique) + propertyId to
  signal-001

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

src/App.tsx

@@ -25,6 +25,7 @@ const MatchCenter = lazy(() => import('./pages/supply/MatchCenter'))
 const Anfragencenter = lazy(() => import('./pages/supply/Anfragencenter'))
 const FutureAvailability = lazy(() => import('./pages/supply/FutureAvailability'))
 const DataQuality = lazy(() => import('./pages/supply/DataQuality'))
+const ReminderManager = lazy(() => import('./pages/supply/ReminderManager'))
 
 const AISearch = lazy(() => import('./pages/demand/AISearch'))
 const Results = lazy(() => import('./pages/demand/Results'))
@@ -56,6 +57,7 @@ function App() {
                 <Route path="/supply/anfragen" element={<Anfragencenter />} />
                 <Route path="/supply/future-availability" element={<FutureAvailability />} />
                 <Route path="/supply/data-quality" element={<DataQuality />} />
+                <Route path="/supply/reminder-manager" element={<ReminderManager />} />
                 <Route path="/supply/market-intelligence" element={<MarketIntelligence />} />
               </Route>