Add structured logging with zerolog

- Implement zerolog logger package with configurable levels
- Add contextual logging middleware (request_id, user_id, method, path, status, duration)
- Support both JSON (production) and human-readable (development) formats
- Add LOG_LEVEL and ENVIRONMENT configuration variables
- Replace standard log calls with structured logger throughout application
- Integrate logger in HTTP router and auth middleware

internal/infrastructure/http/auth_middleware.go

@@ -6,6 +6,7 @@ import (
 	"strings"
 
 	"apocapoc-api/internal/infrastructure/auth"
+	"apocapoc-api/internal/infrastructure/logger"
 )
 
 type contextKey string
@@ -35,6 +36,7 @@ func AuthMiddleware(jwtService *auth.JWTService) func(http.Handler) http.Handler
 			}
 
 			ctx := context.WithValue(r.Context(), UserIDKey, claims.UserID)
+			ctx = logger.AddUserID(ctx, claims.UserID)
 			next.ServeHTTP(w, r.WithContext(ctx))
 		})
 	}