Improve Error Handling Across API

[GautamAnjali569]

Description

Enhance error handling across all API routes to provide meaningful error messages and status codes.

Steps to Implement

1. Create a global error-handling middleware that catches unhandled errors and sends a proper response.
2. Add try/catch blocks and error responses to routes that interact with the database.
3. Standardize error responses to include a consistent error message and HTTP status code.

Expected Outcome

API errors are handled consistently, providing users with clear and meaningful error messages.