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/anfragencenter/OfferPdfReviewStep.tsx

@@ -1,9 +1,8 @@
 import { useEffect, useMemo, useState } from 'react'
 import { Box, Button, CircularProgress, Typography } from '@mui/material'
-import { ArrowLeft, ArrowRight } from 'lucide-react'
+import { ArrowLeft, Send } from 'lucide-react'
 import { useOfferWizardStore } from '../../stores/offerWizardStore'
-import { offerService } from '../../services/offerService'
-import { useUpdateOfferField, useGeneratePdfPreview } from '../../hooks/useOffers'
+import { useUpdateOfferField, useGeneratePdfPreview, useMarkOfferChecked } from '../../hooks/useOffers'
 import { useToastStore } from '../../stores/toastStore'
 import { MockPdfPreview } from './MockPdfPreview'
 import { EditableOfferFieldList } from './EditableOfferFieldList'
@@ -22,6 +21,7 @@ export function OfferPdfReviewStep() {
 
   const updateFieldMut = useUpdateOfferField()
   const genPreview = useGeneratePdfPreview()
+  const markChecked = useMarkOfferChecked()
   const showToast = useToastStore(s => s.showToast)
 
   useEffect(() => {
@@ -66,13 +66,34 @@ export function OfferPdfReviewStep() {
     }
   }
 
-  const handleNext = () => {
+  const needTitle = useOfferWizardStore(s => s.needTitle)
+  const addAttachment = useOfferWizardStore(s => s.addAttachment)
+  const setMessageDraft = useOfferWizardStore(s => s.setMessageDraft)
+  const setMessageSubject = useOfferWizardStore(s => s.setMessageSubject)
+
+  const handleNext = async () => {
     if (!offerDraftId) return
     if (!pdfReady) {
       showToast('PDF-Vorschau wird noch generiert...', 'info')
       return
     }
-    setStep('checked')
+    const res = await markChecked.mutateAsync(offerDraftId)
+    if (res.error) {
+      showToast(`Fehler: ${res.error}`, 'error')
+      return
+    }
+    addAttachment({
+      id: crypto.randomUUID(),
+      fileName: `Angebot_${needTitle.replace(/\s+/g, '_')}.pdf`,
+      fileType: 'application/pdf',
+      fileSize: 320_000,
+      generated: true,
+    })
+    setMessageSubject(`Passende Gewerbeflächen zu Ihrer Anfrage: ${needTitle}`)
+    setMessageDraft(
+      `Sehr geehrte Damen und Herren,\n\nbitte finden Sie anbei unser Angebot zu Ihrem Bedarf "${needTitle}". Gerne stehen wir für Rückfragen und Besichtigungstermine zur Verfügung.\n\nFreundliche Grüsse\nWincasa AG`,
+    )
+    setStep('send')
   }
 
   if (loadingDraft || !draft) {
@@ -153,12 +174,12 @@ export function OfferPdfReviewStep() {
         </Button>
         <Button
           variant="contained"
-          endIcon={<ArrowRight size={14} />}
+          endIcon={markChecked.isPending ? <CircularProgress size={14} sx={{ color: 'white' }} /> : <Send size={14} />}
           onClick={handleNext}
-          disabled={!pdfReady}
+          disabled={!pdfReady || markChecked.isPending}
           sx={{ textTransform: 'none', bgcolor: '#1e3a5f', '&:hover': { bgcolor: '#16304d' } }}
         >
-          Angebot prüfen
+          {markChecked.isPending ? 'Wird geprüft…' : 'Angebot senden →'}
         </Button>
       </Box>
     </Box>