test: add unit tests for Analytics, Search, and Notifications modules

Add 15 test files with 45 test cases covering all untested handlers:
- Analytics: track-event, generate-report, update-market-index, get-heatmap, get-price-trend, get-market-report, get-district-stats
- Search: reindex-all, sync-listing, search-properties, geo-search, listing-approved event handler
- Notifications: send-notification, agent-verified listener, user-registered listener

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/api/src/modules/search/infrastructure/__tests__/listing-approved.handler.spec.ts

@@ -0,0 +1,45 @@
+import { ListingApprovedEventHandler } from '../event-handlers/listing-approved.handler';
+
+describe('ListingApprovedEventHandler', () => {
+  let handler: ListingApprovedEventHandler;
+  let mockIndexer: { indexListing: ReturnType<typeof vi.fn>; removeListing: ReturnType<typeof vi.fn> };
+  let mockLogger: { log: ReturnType<typeof vi.fn>; warn: ReturnType<typeof vi.fn>; error: ReturnType<typeof vi.fn> };
+
+  beforeEach(() => {
+    mockIndexer = {
+      indexListing: vi.fn(),
+      removeListing: vi.fn(),
+    };
+    mockLogger = {
+      log: vi.fn(),
+      warn: vi.fn(),
+      error: vi.fn(),
+    };
+    handler = new ListingApprovedEventHandler(mockIndexer as any, mockLogger as any);
+  });
+
+  it('indexes listing on listing.approved event', async () => {
+    mockIndexer.indexListing.mockResolvedValue(undefined);
+
+    await handler.handle({ listingId: 'listing-1' });
+
+    expect(mockIndexer.indexListing).toHaveBeenCalledWith('listing-1');
+    expect(mockLogger.log).toHaveBeenCalled();
+  });
+
+  it('indexes listing on listing.updated event', async () => {
+    mockIndexer.indexListing.mockResolvedValue(undefined);
+
+    await handler.handleUpdate({ listingId: 'listing-2' });
+
+    expect(mockIndexer.indexListing).toHaveBeenCalledWith('listing-2');
+  });
+
+  it('removes listing on listing.deactivated event', async () => {
+    mockIndexer.removeListing.mockResolvedValue(undefined);
+
+    await handler.handleDeactivation({ listingId: 'listing-3' });
+
+    expect(mockIndexer.removeListing).toHaveBeenCalledWith('listing-3');
+  });
+});