test(crm): update mocks for new createInvitation + OG date-format behavior

Two upstream tests regressed because the CRM PR added expected behavior
they didn't anticipate:

- galleryOgService.shareImage.test.js: formatEventDate is now async and
  routes through utils/dateFormatter so the OG card respects the admin's
  general_date_format setting (per feedback_respect_general_format_settings).
  That adds a third db('app_settings') call on every buildOgMetadata path.
  Mock the formatter module directly — the format itself is irrelevant
  to the cover-vs-logo contract this file pins.

- customerAccountsService.test.js: createInvitation now allows a duplicate
  email when the existing row is PASSIVE (password_hash IS NULL) — that's
  the "promote passive customer to portal" path. The active-customer
  rejection mock now has to set password_hash so the guard fires.

Both are test-only changes; no service code touched.

backend/src/__tests__/customerAccountsService.test.js

@@ -66,7 +66,11 @@ beforeEach(() => {
 describe('createInvitation', () => {
   it('rejects when a customer with the email already exists', async () => {
     const svc = require('../services/customerAccountsService');
-    db.mockImplementationOnce(() => chain({ first: { id: 1, email: 'taken@example.com' } }));
+    // Service only rejects when the existing row has a password_hash —
+    // a passive (password_hash = null) row is the "promote to portal"
+    // path and is allowed through. Pin the rejection contract by mocking
+    // an active row.
+    db.mockImplementationOnce(() => chain({ first: { id: 1, email: 'taken@example.com', password_hash: 'hash' } }));
     await expect(
       svc.createInvitation({ email: 'taken@example.com', invitedById: 9 })
     ).rejects.toThrow(/already exists/i);

backend/src/__tests__/galleryOgService.shareImage.test.js

@@ -29,6 +29,14 @@ jest.mock('../services/storage', () => ({
   getStorage: jest.fn(),
 }));
 
+// dateFormatter.formatDate queries `app_settings` for general_date_format,
+// which would add a third unmocked db() call to every buildOgMetadata path.
+// The format itself is irrelevant to the cover-vs-logo contract this file
+// pins — short-circuit it to a stable string so the tests stay focused.
+jest.mock('../utils/dateFormatter', () => ({
+  formatDate: jest.fn().mockResolvedValue('12.06.2026'),
+}));
+
 const { db } = require('../database/db');
 const { ensureThumbnail } = require('../services/imageProcessor');
 const { getStorage } = require('../services/storage');