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);

backend/src/utils/logger.js

@@ -0,0 +1,43 @@
+const winston = require('winston');
+const path = require('path');
+
+// Log format
+const logFormat = winston.format.combine(
+  winston.format.timestamp({ format: 'YYYY-MM-DD HH:mm:ss' }),
+  winston.format.errors({ stack: true }),
+  winston.format.printf(({ timestamp, level, message, stack }) => {
+    return `${timestamp} [${level.toUpperCase()}]: ${stack || message}`;
+  })
+);
+
+// Logger instance
+const logger = winston.createLogger({
+  level: process.env.LOG_LEVEL || 'info',
+  format: logFormat,
+  transports: [
+    // Console transport
+    new winston.transports.Console({
+      format: winston.format.combine(
+        winston.format.colorize(),
+        logFormat
+      ),
+    }),
+    // File transport - errors
+    new winston.transports.File({
+      filename: path.join(__dirname, '../../logs/error.log'),
+      level: 'error',
+      maxsize: 5242880, // 5MB
+      maxFiles: 5,
+    }),
+    // File transport - combined
+    new winston.transports.File({
+      filename: path.join(__dirname, '../../logs/combined.log'),
+      maxsize: 5242880, // 5MB
+      maxFiles: 5,
+    }),
+  ],
+  exitOnError: false,
+});
+
+module.exports = logger;
+