feat: add global error handling middleware

[morelucks]

feat: add global error handling middleware

Overview

This PR implements a robust, centralized error-handling architecture for the Creditra API. It standardizes error responses, automates HTTP status code mapping, and ensures secure, structured logging across all service routes.

Key Changes

Core Architecture

• AppError Class: A custom extension of the native Error class designed to carry typed ErrorCodes and optional details for context-rich debugging.
• Factory Helpers: Implementation of semantic helpers (validationError, notFoundError, authenticationError, etc.) to streamline error creation in route handlers.
• Unified JSON Envelope: Enforces a consistent response structure across the entire API:

  {
    "error": "Human readable message",
    "code": "ERROR_CATEGORY_CODE",
    "details": { "optional": "metadata" }
  }
  

closes #2

[greatest0fallt1me]

please resolve the conflicts

[morelucks]

fixed
@greatest0fallt1me

[greatest0fallt1me]

@morelucks Can you resolve the conflicts?