feat: F030 Anfragencenter — Aktive & Latente Anfragen + Angebot-Wizard

Neuer Menüpunkt «Anfragencenter» (ehemals «Eingehende Bedarfe»):

Aktive Anfragen:
- Split-View: Anfrageliste (Liste/Grid-Toggle) + Chat-Detailansicht
- Chat-Verlauf mit Sender-Styling (Mieter links, Supply rechts)
- Antwortformular mit Betreff, Nachricht, Anhänge, Statuswechsel
- Zugehörige Property Card neben dem Chat

Latente Anfragen:
- Drei-Spalten-Layout: Need-Liste | Need-Detail | Eigene Objekte
- Need Cards mit AI-Zusammenfassung, Must-Haves, Präferenzen
- Eigene Portfolio-Objekte sortiert nach deterministischem Match-Score
- Checkbox-Selektion für Angebotsauswahl

Angebot-Wizard (4 Schritte):
- Schritt 1: Objekte auswählen (mit Score-Vorschau)
- Schritt 2: PDF-Vorschau + editierbare Textfelder
- Schritt 3: Angebot prüfen & bestätigen
- Schritt 4: Nachricht an Suchenden mit KI-generierter Mail

Architektur:
- Domain: Inquiry, LatentNeed, OfferDraft Types
- Provider: IInquiryProvider, ILatentNeedProvider, IOfferProvider + Mockups
- Services: inquiryService, latentNeedService, offerService
- Hooks: useInquiries, useLatentNeeds, useOffers (TanStack Query)
- Store: offerWizardStore (Zustand, lokaler Wizard-State)
- 27 neue Komponenten, alle Loading/Empty/Error States

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

src/components/anfragencenter/MockPdfPreview.tsx

@@ -0,0 +1,95 @@
+import { Box, Typography } from '@mui/material'
+import { FileText } from 'lucide-react'
+import { useOfferWizardStore } from '../../stores/offerWizardStore'
+import { mockProperties } from '../../mock-data/properties'
+
+interface MockPdfPreviewProps {
+  fields: Record<string, string>
+  fallbackFields: Record<string, string>
+}
+
+export function MockPdfPreview({ fields, fallbackFields }: MockPdfPreviewProps) {
+  const needTitle = useOfferWizardStore(s => s.needTitle)
+  const propertyIds = useOfferWizardStore(s => s.selectedPropertyIds)
+
+  const properties = mockProperties.filter(p => propertyIds.includes(p.id))
+
+  const v = (id: string) => fields[id] ?? fallbackFields[id] ?? ''
+
+  return (
+    <Box
+      sx={{
+        bgcolor: 'white',
+        borderRadius: 1.5,
+        border: '1px solid #cbd5e1',
+        boxShadow: '0 4px 16px rgba(15,23,42,0.08)',
+        p: 4,
+        height: '100%',
+        overflowY: 'auto',
+        fontFamily: '"Georgia", "Times New Roman", serif',
+      }}
+    >
+      <Box sx={{ display: 'flex', alignItems: 'center', gap: 1, mb: 3, color: '#64748b' }}>
+        <FileText size={16} />
+        <Typography variant="caption" sx={{ textTransform: 'uppercase', letterSpacing: 1, fontSize: '0.7rem' }}>
+          Angebotsvorschau (PDF)
+        </Typography>
+      </Box>
+
+      <Typography variant="caption" sx={{ display: 'block', color: '#94a3b8', textAlign: 'right' }}>
+        Wincasa AG · Zürich
+      </Typography>
+      <Typography variant="caption" sx={{ display: 'block', color: '#94a3b8', textAlign: 'right', mb: 4 }}>
+        {new Date().toLocaleDateString('de-CH')}
+      </Typography>
+
+      <Typography variant="h6" sx={{ fontWeight: 700, color: '#0f172a', mb: 2, fontSize: '1.05rem' }}>
+        Angebot: {needTitle}
+      </Typography>
+
+      <Typography variant="body2" sx={{ mb: 1.5, fontSize: '0.875rem' }}>
+        {v('recipient_salutation')},
+      </Typography>
+
+      <Typography variant="body2" sx={{ mb: 2, fontSize: '0.875rem', lineHeight: 1.6, whiteSpace: 'pre-wrap' }}>
+        {v('offer_intro')}
+      </Typography>
+
+      <Typography variant="body2" sx={{ mb: 1, fontWeight: 700, fontSize: '0.875rem' }}>
+        Hervorgehobene Kriterien
+      </Typography>
+      <Typography variant="body2" sx={{ mb: 2.5, fontSize: '0.875rem', lineHeight: 1.6, whiteSpace: 'pre-wrap' }}>
+        {v('highlighted_criteria')}
+      </Typography>
+
+      <Typography variant="body2" sx={{ mb: 1, fontWeight: 700, fontSize: '0.875rem' }}>
+        Vorgeschlagene Objekte
+      </Typography>
+      <Box component="ul" sx={{ pl: 2, mb: 2.5 }}>
+        {properties.map(p => (
+          <Typography
+            key={p.id}
+            component="li"
+            variant="body2"
+            sx={{ fontSize: '0.875rem', mb: 0.5, lineHeight: 1.5 }}
+          >
+            <strong>{p.title}</strong> — {p.location.city}, {p.areaSqm.toLocaleString('de-CH')} m², CHF {p.rentPricePerSqm}/m²
+          </Typography>
+        ))}
+        {properties.length === 0 && (
+          <Typography variant="body2" sx={{ color: '#94a3b8', fontStyle: 'italic' }}>
+            Keine Objekte ausgewählt.
+          </Typography>
+        )}
+      </Box>
+
+      <Typography variant="body2" sx={{ mb: 2.5, fontSize: '0.875rem', lineHeight: 1.6, whiteSpace: 'pre-wrap' }}>
+        {v('next_steps')}
+      </Typography>
+
+      <Typography variant="body2" sx={{ fontSize: '0.875rem', whiteSpace: 'pre-wrap', lineHeight: 1.6 }}>
+        {v('closing')}
+      </Typography>
+    </Box>
+  )
+}