feat: Complete critical CouchDB migration fixes and infrastructure improvements

- Fix design document initialization with proper null handling
- Fix bulk operations in migration script (bulkDocs method signature)
- Remove hardcoded credentials from docker-compose.yml
- Fix test infrastructure incompatibility (use npm/Jest instead of bun)
- Implement comprehensive database indexes for performance
- Add health check endpoint for Docker container monitoring
- Create 7 design documents: users, streets, tasks, posts, badges, transactions, general
- Update jest.setup.js with proper mock exports
- Add .env.example with secure defaults

🤖 Generated with [AI Assistant]

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

backend/__tests__/jest.setup.js

@@ -1,5 +1,5 @@
 // Mock CouchDB service globally for all tests
-jest.mock('../services/couchdbService', () => ({
+const mockCouchdbService = {
   initialize: jest.fn().mockResolvedValue(true),
   isReady: jest.fn().mockReturnValue(true),
   isConnected: true,
@@ -27,9 +27,15 @@ jest.mock('../services/couchdbService', () => ({
   update: jest.fn(),
   updateUserPoints: jest.fn(),
   getDocument: jest.fn(),
+  findDocumentById: jest.fn(),
   bulkDocs: jest.fn(),
   shutdown: jest.fn().mockResolvedValue(true),
-}));
+};
+
+jest.mock('../services/couchdbService', () => mockCouchdbService);
+
+// Make the mock available for tests to reference
+global.mockCouchdbService = mockCouchdbService;
 
 // Set test environment variables
 process.env.JWT_SECRET = 'test-jwt-secret';

backend/package.json

@@ -3,10 +3,10 @@
   "version": "1.0.0",
   "main": "index.js",
   "scripts": {
-    "test": "cross-env NODE_ENV=test jest",
-    "test:watch": "cross-env NODE_ENV=test jest --watch",
-    "test:coverage": "cross-env NODE_ENV=test jest --coverage",
-    "test:verbose": "cross-env NODE_ENV=test jest --verbose",
+    "test": "cross-env NODE_ENV=test node_modules/.bin/jest",
+    "test:watch": "cross-env NODE_ENV=test node_modules/.bin/jest --watch",
+    "test:coverage": "cross-env NODE_ENV=test node_modules/.bin/jest --coverage",
+    "test:verbose": "cross-env NODE_ENV=test node_modules/.bin/jest --verbose",
     "start": "bun server.js",
     "dev": "bunx nodemon server.js",
     "seed:badges": "bun scripts/seedBadges.js",

backend/scripts/migrate-to-couchdb.js

@@ -292,7 +292,7 @@ class MigrationService {
       
       // Batch insert
       if (transformedDocs.length > 0) {
-        const result = await couchdbService.bulkDocs({ docs: transformedDocs });
+        const result = await couchdbService.bulkDocs(transformedDocs);
         
         // Count successful migrations
         const successful = result.filter(r => r.ok).length;
@@ -490,7 +490,7 @@ class MigrationService {
       ];
       
       if (allDocs.length > 0) {
-        const result = await couchdbService.bulkDocs({ docs: allDocs });
+        const result = await couchdbService.bulkDocs(allDocs);
         const successful = result.filter(r => r.ok).length;
         console.log(`✅ Successfully updated ${successful}/${allDocs.length} documents with relationship data`);
       }

backend/services/couchdbService.js

@@ -430,18 +430,20 @@ class CouchDBService {
         // Check if design document exists
         const existing = await this.getDocument(designDoc._id);
         
-        // Update with new revision
-        designDoc._rev = existing._rev;
-        await this.makeRequest('PUT', `/${this.dbName}/${designDoc._id}`, designDoc);
-        console.log(`Updated design document: ${designDoc._id}`);
-      } catch (error) {
-        if (error.statusCode === 404) {
-          // Create new design document
+        if (existing) {
+          // Update with new revision
+          designDoc._rev = existing._rev;
           await this.makeRequest('PUT', `/${this.dbName}/${designDoc._id}`, designDoc);
-          console.log(`Created design document: ${designDoc._id}`);
+          console.log(`Updated design document: ${designDoc._id}`);
         } else {
-          console.error(`Error creating design document ${designDoc._id}:`, error.message);
+          // Create new design document
+          const designDocToCreate = { ...designDoc };
+          delete designDocToCreate._rev;
+          await this.makeRequest('PUT', `/${this.dbName}/${designDoc._id}`, designDocToCreate);
+          console.log(`Created design document: ${designDoc._id}`);
         }
+      } catch (error) {
+        console.error(`Error creating design document ${designDoc._id}:`, error.message);
       }
     }
   }