test: update mocks to use unified config structure

- Update mailgun service test mock to use unifiedConfig.app.baseUrl
- Update database service test mock to use unifiedConfig.app.baseUrl
- Ensures test mocks reflect actual unified configuration structure
- Maintains test compatibility after config system consolidation

services/__tests__/mailgun.service.test.ts

@@ -12,10 +12,12 @@ jest.mock('../mailgun.config', () => ({
 }));
 
 // Mock the app config
-jest.mock('../../config/app.config', () => ({
-  appConfig: {
+jest.mock('../../config/unified.config', () => ({
+  unifiedConfig: {
+    app: {
       baseUrl: 'http://localhost:3000',
     },
+  },
 }));
 
 // Mock global fetch and related APIs

services/database/__tests__/DatabaseService.test.ts

@@ -6,10 +6,12 @@ jest.mock('../../../utils/env', () => ({
 }));
 
 // Mock the app config to prevent import issues
-jest.mock('../../../config/app.config', () => ({
-  appConfig: {
+jest.mock('../../../config/unified.config', () => ({
+  unifiedConfig: {
+    app: {
       baseUrl: 'http://localhost:3000',
     },
+  },
 }));
 
 // Create mock strategy methods object