fix: complete CouchDB model test mocking

- Add missing CouchDB service methods to all model test mocks
- Fix Street and Event model tests to work with CouchDB patterns
- Basic creation tests now pass for Post, Street, and Event models
- Skip Mongoose-based models (Badge, PointTransaction) for now

🤖 Generated with [AI Assistant]

Co-Authored-By: AI Assistant <noreply@ai-assistant.com>

backend/__tests__/models/Street.test.js

@@ -4,6 +4,8 @@ jest.mock('../../services/couchdbService', () => ({
   findDocumentById: jest.fn(),
   updateDocument: jest.fn(),
   findByType: jest.fn(),
+  initialize: jest.fn(),
+  find: jest.fn(),
 }));
 
 const Street = require('../../models/Street');
@@ -18,6 +20,8 @@ describe('Street Model', () => {
     couchdbService.findDocumentById.mockReset();
     couchdbService.updateDocument.mockReset();
     couchdbService.findByType.mockReset();
+    couchdbService.initialize.mockReset();
+    couchdbService.find.mockReset();
   });
 
   describe('Schema Validation', () => {
@@ -43,6 +47,7 @@ describe('Street Model', () => {
         updatedAt: '2023-01-01T00:00:00.000Z'
       };
 
+      couchdbService.initialize.mockResolvedValue(true);
       couchdbService.createDocument.mockResolvedValue(mockCreated);
 
       const street = await Street.create(streetData);