feat(messages): unified conversation inbox — connect demand ↔ supply, offers reach the seeker

Phase 1 of the messaging rework: one conversation/thread model (Inquiry) is the single source of truth, read perspectivally by both sides.

- domain/inquiry: add kind (INQUIRY|OFFER), tenantOrgId (demand org), offeredPropertyIds
- provider/service: InquiryFilters gains tenantOrgId+kind; new createInquiry (demand→supply) & createOffer (supply→demand) materialize threads; addMessage bumps unread; reply carries senderType (tenant vs supply_user)
- hooks: useCreateInquiry, useCreateOffer; reply payload carries sender perspective
- demand: InquiryQuickDialog → createInquiry via provider (session-based tenant/org, no hardcode); Anfragen.tsx reads via React Query (tenantOrgId) with Gesendet/Erhalten tabs, replies via provider, shows offered properties for OFFER threads; inquiryStore reduced to dialog-only (removes Zustand server-data island)
- supply: OfferChatComposer send now materializes an OFFER conversation into the seeker's inbox (routed via latentNeed.tenantOrgId); Anfragencenter gains a "Gesendet" tab; ActiveInquiriesTab filters by perspective (org + kind)
- seed: merge demand inquiries with tenantOrgId=org-mobimo + 2 OFFER seeds; provider seeds from both sets

Closes the loop: a sent inquiry reaches the Verwaltung and a sent offer reaches the Nachfrager — both answerable in one thread.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/mock-data/demandInquiries.ts

@@ -5,6 +5,8 @@ export const mockDemandInquiries: Inquiry[] = [
   {
     id: 'dinq-001',
     organizationId: 'org-wincasa',
+    tenantOrgId: 'org-mobimo',
+    kind: 'INQUIRY',
     propertyId: 'prop-technopark',
     tenantName: 'Admin User',
     tenantCompany: 'Mobimo Management AG',
@@ -39,6 +41,8 @@ export const mockDemandInquiries: Inquiry[] = [
   {
     id: 'dinq-002',
     organizationId: 'org-wincasa',
+    tenantOrgId: 'org-mobimo',
+    kind: 'INQUIRY',
     propertyId: 'prop-hardturmpark',
     tenantName: 'Admin User',
     tenantCompany: 'Mobimo Management AG',
@@ -73,6 +77,8 @@ export const mockDemandInquiries: Inquiry[] = [
   {
     id: 'dinq-003',
     organizationId: 'org-wincasa',
+    tenantOrgId: 'org-mobimo',
+    kind: 'INQUIRY',
     propertyId: 'prop-sihlcity',
     tenantName: 'Admin User',
     tenantCompany: 'Mobimo Management AG',
@@ -130,6 +136,8 @@ export const mockDemandInquiries: Inquiry[] = [
   {
     id: 'dinq-004',
     organizationId: 'org-wincasa',
+    tenantOrgId: 'org-mobimo',
+    kind: 'INQUIRY',
     propertyId: 'prop-bahnhofzug',
     tenantName: 'Admin User',
     tenantCompany: 'Mobimo Management AG',
@@ -186,6 +194,8 @@ export const mockDemandInquiries: Inquiry[] = [
   {
     id: 'dinq-005',
     organizationId: 'org-wincasa',
+    tenantOrgId: 'org-mobimo',
+    kind: 'INQUIRY',
     propertyId: 'prop-dreispitz',
     tenantName: 'Admin User',
     tenantCompany: 'Mobimo Management AG',
@@ -238,4 +248,40 @@ export const mockDemandInquiries: Inquiry[] = [
       },
     ],
   },
+
+  // 6 — OFFER (Verwaltung → Nachfrager, proaktiv aus Latente Anfragen)
+  {
+    id: 'off-seed-001',
+    organizationId: 'org-wincasa',
+    tenantOrgId: 'org-mobimo',
+    kind: 'OFFER',
+    propertyId: 'prop-001',
+    offeredPropertyIds: ['prop-001', 'prop-093'],
+    tenantName: 'Mobimo Management AG',
+    propertyManagerCompany: 'Wincasa AG',
+    propertyAddress: '2 Objekte im Angebot',
+    subject: 'Passende Büroflächen zu Ihrem Bedarf',
+    message:
+      'Sehr geehrte Damen und Herren,\n\nbasierend auf Ihrem Suchprofil haben wir zwei passende Büroflächen für Sie zusammengestellt. Details finden Sie im beigefügten Angebot.\n\nFreundliche Grüsse\nWincasa AG',
+    status: 'new',
+    unreadCount: 1,
+    isRead: false,
+    createdAt: '2026-05-24T10:00:00Z',
+    updatedAt: '2026-05-24T10:00:00Z',
+    thread: [
+      {
+        id: 'off-seed-001-1',
+        inquiryId: 'off-seed-001',
+        senderType: 'supply_user',
+        senderName: 'Wincasa AG',
+        subject: 'Passende Büroflächen zu Ihrem Bedarf',
+        body:
+          'Sehr geehrte Damen und Herren,\n\nbasierend auf Ihrem Suchprofil haben wir zwei passende Büroflächen für Sie zusammengestellt. Details finden Sie im beigefügten Angebot.\n\nFreundliche Grüsse\nWincasa AG',
+        attachments: [
+          { id: 'off-att-001', fileName: 'Angebot_Bueroflaechen_Zuerich.pdf', fileType: 'application/pdf', fileSize: 312500, generated: true },
+        ],
+        createdAt: '2026-05-24T10:00:00Z',
+      },
+    ],
+  },
 ]