# mapBoth

Transforms both the success and error channels of an Fx using the provided options.

Mirrors `Effect.mapBoth`: `onSuccess` maps emitted values, `onFailure` maps the
typed failure (via `Cause.map`); defects and interrupts are preserved.

## Signatures

```ts
export declare const mapBoth: {
    <E, E2, A, A2>(options: {
        readonly onFailure: (e: E) => E2;
        readonly onSuccess: (a: A) => A2;
    }): <R>(self: Fx<A, E, R>) => Fx<A2, E2, R>;
    <A, E, R, E2, A2>(self: Fx<A, E, R>, options: {
        readonly onFailure: (e: E) => E2;
        readonly onSuccess: (a: A) => A2;
    }): Fx<A2, E2, R>;
};
```

## Why

`mapBoth` transforms success values and typed failures together while preserving the rest of an
Effect `Cause`. Every success still emits once in order; only typed failure values are mapped.

## Ownership and lifetime

Both callbacks are synchronous and the operation acquires no resources. Defects, interruption,
service requirements, and source lifetime pass through unchanged.

## Examples

```ts
import { Fx } from "@typed/fx"

const normalized = Fx.fail("offline").pipe(Fx.mapBoth({
  onFailure: (message) => new Error(message),
  onSuccess: (value) => String(value),
}))
```