fix: Add missing logger.js and fix Ollama routes middleware

- Add backend/src/utils/logger.js (Winston logger)
- Fix ollama.routes.js middleware import (requireAuth instead of isAuthenticated)
- Add axios to package.json dependencies
- Create logs directory for Winston
- Fix module paths for Ollama integration

This fixes the backend startup issues after Ollama integration.

backend/src/routes/ollama.routes.js

@@ -1,10 +1,10 @@
 const express = require('express');
 const router = express.Router();
 const ollamaController = require('../controllers/ollama.controller');
-const { isAuthenticated } = require('../middleware/auth.middleware');
+const { requireAuth } = require('../middlewares/auth');
 
 // All routes require authentication
-router.use(isAuthenticated);
+router.use(requireAuth);
 
 // Test Ollama connection
 router.get('/test', ollamaController.testConnection);