Add serialization support to custom exceptions

[coderabbitai]

Background

This issue tracks the implementation of proper serialization support for custom exceptions in the codebase.

Requirement

Custom exceptions like DatabaseOperationException should implement serialization support for scenarios where exceptions cross application boundaries (between processes, app domains, or during remote calls).

Implementation Details

For each custom exception class:

1. Add the [Serializable] attribute
2. Add protected constructor for SerializationInfo and StreamingContext

Example implementation:

[Serializable]
public class DatabaseOperationException : Exception
{
    public DatabaseOperationException() : base() { }

    public DatabaseOperationException(string msg) : base(msg) { }

    public DatabaseOperationException(string message, Exception innerException) 
        : base(message, innerException) { }

    protected DatabaseOperationException(
        System.Runtime.Serialization.SerializationInfo info,
        System.Runtime.Serialization.StreamingContext context
    ) : base(info, context)
    {
    }
}

References

• Discussed in PR: feat: implement soft delete for users and roles #11 (comment)
• File: src/Core/Exceptions/DatabaseOperationException.cs
• Microsoft guidelines: CA1032, CA2237