[Backend] Implement `LoggingMiddleware`

[Muhammadcodes112]

Description

Basic request logging — method, path, status code, response time — for every incoming request.

Where

astre_server/src/common/logging.middleware.ts (new file)

What to implement

A class implementing NestMiddleware that logs ${method} ${originalUrl} ${statusCode} - ${responseTime}ms when the response finishes (hook into the response's finish event).

Acceptance Criteria

• Every request produces exactly one log line
• The logged line includes method, path, status code, and response time
• npm run build compiles cleanly

[sidd51]

I'd like to work on this, please assign it to me.