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/package.json

@@ -18,6 +18,7 @@
   "author": "",
   "license": "MIT",
   "dependencies": {
+    "axios": "^1.13.2",
     "bcrypt": "^5.1.1",
     "connect-sqlite3": "^0.9.16",
     "cors": "^2.8.5",