feat: all 4 UX priorities — wizard, examples, onboarding, pipeline

- Offer wizard: 4→3 steps by merging 'Prüfen' into PDF review step
- Search mask: quick-select chips for area ranges, budget, and city presets
- Onboarding: WelcomeDialog (3 slides, localStorage) on first visit
- Deal Pipeline: Kanban board (6 stages, 8 mock items, advance-to-next-stage)
  added to demand workspace navigation

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

src/App.tsx

@@ -32,6 +32,7 @@ const Results = lazy(() => import('./pages/demand/Results'))
 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 ReviewQueue = lazy(() => import('./pages/ops/ReviewQueue'))
 const AIMonitoring = lazy(() => import('./pages/ops/AIMonitoring'))
@@ -71,6 +72,7 @@ function App() {
                 <Route path="/demand/results/:matchId" element={<MatchDetail />} />
                 <Route path="/demand/compare" element={<Compare />} />
                 <Route path="/demand/shortlists" element={<Shortlists />} />
+                <Route path="/demand/pipeline" element={<Pipeline />} />
               </Route>
 
               {/* Operations Workspace */}