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/components/layout/AppShell.tsx

@@ -1,5 +1,6 @@
 import { useEffect, useState } from 'react'
 import { Outlet, NavLink, useNavigate, useLocation } from 'react-router'
+import { WelcomeDialog } from '../onboarding/WelcomeDialog'
 import { useLayoutStore } from '../../stores/layoutStore'
 import { useSessionStore } from '../../stores/sessionStore'
 import { WorkspaceType } from '../../domain/enums'
@@ -37,6 +38,7 @@ import {
   GitBranch,
   MessageSquare,
   Menu,
+  Kanban,
 } from 'lucide-react'
 import type { LucideIcon } from 'lucide-react'
 import { OrganizationContextBadge } from './OrganizationContextBadge'
@@ -97,6 +99,7 @@ const WORKSPACE_CONFIG: Record<WorkspaceType, WorkspaceConfig> = {
       { path: '/demand/results', label: 'Ergebnisse', icon: List },
       { path: '/demand/compare', label: 'Vergleich', icon: Columns2 },
       { path: '/demand/shortlists', label: 'Shortlists', icon: Bookmark },
+      { path: '/demand/pipeline', label: 'Deal Pipeline', icon: Kanban },
     ],
   },
   [WorkspaceType.OPERATIONS]: {
@@ -598,6 +601,7 @@ export function AppShell() {
       <GlobalAIAssistantDrawer />
       <GlobalAIAssistantButton />
       <ToastProvider />
+      <WelcomeDialog />
     </Box>
   )
 }