feat: enhance security logging and ensure rate limit blocks are properly tracked

- Add comprehensive logging for rate limit blocks with full request details
  - IP address (with proper proxy detection), user agent, headers, timestamps
  - Rate limit info (current count, limit, remaining, reset time)
  - Separate tracking for auth vs general endpoints

- Enhance authentication failure logging
  - JWT validation failures with detailed error info
  - Admin auth attempts without token
  - Failed token validation with user context
  - All events include IP, path, method, user agent

- Improve Winston logger configuration for production
  - Add automatic log rotation (10MB errors, 50MB combined)
  - Create separate security.log for auth/rate limit events
  - Ensure logs directory exists automatically
  - Add structured JSON format for log aggregation
  - Support container logging with LOG_TO_CONSOLE env var

- Create comprehensive documentation
  - Security logging guide with examples
  - Monitoring recommendations
  - Configuration reference

- Add test script to verify logging functionality

All rate limit settings remain configurable via admin panel:
- Window duration, max requests, auth limits
- Skip authenticated requests option
- Public endpoints only option

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

backend/server.js

@@ -4,6 +4,14 @@ require('dotenv').config();
 const { validateEnvironment } = require('./src/config/validateEnv');
 validateEnvironment();
 
+// Initialize logger early to capture startup logs
+const logger = require('./src/utils/logger');
+logger.info('Server starting up', {
+  nodeVersion: process.version,
+  environment: process.env.NODE_ENV || 'development',
+  timestamp: new Date().toISOString()
+});
+
 const express = require('express');
 const helmet = require('helmet');
 const cors = require('cors');