**Core Library - Type-Safe Error Handling**

// Fluent, chainable operations
var result = await Result<string>.Ok(email)
    .Ensure(e => IsValidEmail(e), "Invalid email format")
    .EnsureAsync(async e => !await EmailExistsAsync(e), "Email already registered")
    .BindAsync(async e => await CreateUserAsync(e))
    .WithSuccess("User created successfully");

// Pattern matching
return result.Match(
    onSuccess: user => CreatedAtAction(nameof(GetUser), new { id = user.Id }, user),
    onFailure: errors => BadRequest(new { errors })
);