feat: Anfragencenter Parts A–E — read/unread, prep wizard, offer flow, report preview

- Part A: Replace InquiryStatus badges with WhatsApp-style unread indicators
  (isRead, unreadCount, lastReadAt on Inquiry; markThreadAsRead in service + hook)
- Part B: RelatedPropertyCardPanel — reposition "Objekt ansehen", add "Weitere
  Matches" section via matchService.getAdditionalMatchesForInquiry
- Part C: PreparationWizard 4-step dialog — property selection, report generation
  progress, field editing + ReportObjectFieldSelector, PDF preview + finalize
- Part D: OfferCreationWizard 4-step dialog triggered from first tenant message —
  data capture, field editing, viewing appointments, PDF generation + attach to reply
- Part E: LatentInquiryReportPreview (2-page A4 doc), ReportObjectFieldSelector
  (5 accordion groups, 35+ optional fields), mapImageUrl on Property domain

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

src/provider/IInquiryProvider.ts

@@ -10,6 +10,8 @@ export interface IInquiryProvider {
   getAll(filters?: InquiryFilters): Promise<Inquiry[]>
   getById(id: string): Promise<Inquiry | null>
   updateStatus(id: string, status: InquiryStatus): Promise<Inquiry>
+  markThreadAsRead(id: string): Promise<Inquiry>
+  getUnreadCount(): Promise<number>
   addMessage(
     inquiryId: string,
     msg: Omit<InquiryMessage, 'id' | 'inquiryId' | 'createdAt'>,

src/provider/MockupInquiryProvider.ts

@@ -21,6 +21,21 @@ export const MockupInquiryProvider: IInquiryProvider = {
     store[idx] = { ...store[idx], status, updatedAt: new Date().toISOString() }
     return store[idx]
   },
+  async markThreadAsRead(id: string): Promise<Inquiry> {
+    const idx = store.findIndex(i => i.id === id)
+    if (idx === -1) throw new Error(`Inquiry ${id} not found`)
+    store[idx] = {
+      ...store[idx],
+      isRead: true,
+      unreadCount: 0,
+      lastReadAt: new Date().toISOString(),
+      updatedAt: new Date().toISOString(),
+    }
+    return store[idx]
+  },
+  async getUnreadCount(): Promise<number> {
+    return store.reduce((sum, i) => sum + (i.unreadCount ?? 0), 0)
+  },
   async addMessage(
     inquiryId: string,
     msg: Omit<InquiryMessage, 'id' | 'inquiryId' | 'createdAt'>,