Integrate Winston Structured Logging Middleware to Record Method, Path, Status, and Duration per Request

[mftee]

Description:
Add structured request/response logging using Winston as an independent middleware layer, so every inbound HTTP request is logged with method, path, status code, and duration.

Tasks:

• Install winston and nest-winston
• Create src/common/middleware/logger.middleware.ts implementing NestMiddleware
• Log: method, url, status, duration_ms, user_agent, ip
• Apply the middleware globally in AppModule
• Replace default NestJS logger with Winston logger in main.ts
• Add LOG_LEVEL env var (debug, info, warn, error) to .env.example

Acceptance Criteria:

• Every request produces a structured log line in JSON format
• Log level is configurable via env var
• Sensitive headers (Authorization) are redacted from logs