Evaluation: Structured errors for limits

[vprashrex]

Is your feature request related to a problem?
When using the evaluations API with an invalid limit value (e.g., -1), it returns a raw PostgreSQL database error instead of a structured validation error. This exposes internal SQL details and disrupts standard API error handling.

Describe the solution you'd like

• Return a structured validation error instead of a raw SQL error for invalid limit values.
• Ensure error response format matches the expected behavior outlined above.

Original issue

Describe the bug
When calling the evaluations API with an invalid limit value (e.g., -1), the API returns a raw database error from PostgreSQL instead of a structured validation error.
This exposes internal SQL details and breaks expected API error handling standards.

To Reproduce
Steps to reproduce the behavior:
Send a GET request to:
/api/v1/evaluations?limit=-1&offset=0
Observe the response

Expected behavior

{
    "success": false,
    "data": null,
    "error": "Validation failed",
    "errors": [
        {
            "field": "query.limit",
            "message": "Input should be greater than 0"
        }
    ],
    "metadata": null
}

Screenshots

Additional context
Add any other context about the problem here.